JP2009103111A - Cooling system and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling system capable of efficient cooling with an excellent waterproofness, a piezoelectric pump, and an electronic equipment. <P>SOLUTION: This cooling system 1 includes a bottom part 10 of a housing 3 having a passage 31 for introducing gas from outside, a piezoelectric pump 32 for introducing the gas from the outside via the passage 31 and jetting the gas from inside, and a filter 33 provided to block the passage 31, allowing at least the gas, but restraining passage of liquid. So, the system does not suck water drops, so as to obtain a portable video camera 1 with excellent waterproofness. The piezoelectric pump 32 has a high static pressure of about 2 KPa, and there is little possibility that a suction force of the piezoelectric pump 32 is substantially reduced by the filter 33. Accordingly, cooling can be efficiently done. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cooling device, a piezoelectric pump, and an electronic device used for cooling a hard disk drive mounted on a portable electronic device such as a portable video camera.

  Conventionally, as a technique for cooling an electronic component mounted on a portable electronic device, it is well known to forcibly exhaust the inside of a housing with a cooling fan (see, for example, Patent Document 1).

  However, including a space for securing a fan and an air passage, the volume is large, which is a factor that hinders the recent miniaturization and thinning of portable electronic devices. There is also a problem of noise generated from the fan. In particular, when a recording function such as a portable video camera is provided, the noise problem is fatal.

As a technique for solving these problems, for example, a "jet generator" is disclosed in which a diaphragm is vibrated at a frequency that is difficult for humans to hear in a chamber having a nozzle for ejecting gas, and a cooling gas is ejected from the nozzle. (Patent Document 2).
Japanese Patent Laying-Open No. 2005-12132 (paragraph [0019], FIG. 2) JP 2006-297295 A (paragraphs [0029] to [0031], FIG. 2)

  Portable electronic devices such as portable video cameras and cellular phones are held by wet hands, for example, or there is an opportunity for water droplets to adhere to the case during precipitation. If introduced from the outside, water droplets will enter the device and cause a failure of the device.

  In view of the circumstances as described above, an object of the present invention is to provide a cooling device, a piezoelectric pump, and an electronic device that are excellent in waterproofness and can perform cooling efficiently.

  In order to solve such a problem, a cooling device according to the present invention includes a gas introduction part having a passage for introducing a gas from the outside, and a piezoelectric that introduces the gas from the outside through the passage and ejects the gas from the inside. A pump and a filter provided so as to close the passage, and at least a gas passes but restricts the passage of the liquid.

  In the present invention, a filter for restricting the passage of the liquid is provided in the passage for introducing the gas from the outside to the piezoelectric pump so that the passage of the gas is restricted so that the passage of the liquid is blocked. Will be excellent in waterproofness. Also, since the piezoelectric pump has a high static pressure, even if the filter is provided in the passage for introducing gas from the outside to the piezoelectric pump, the suction force by the piezoelectric pump is not substantially reduced. Cooling can be performed efficiently.

  In addition, in the present invention, by providing the above-described filter, for example, the opportunity for dust to be sucked into a portable electronic device in which the cooling device according to the present invention is mounted is drastically reduced. The resulting failure of the electronic equipment is greatly reduced. Further, by using the piezoelectric pump, it is excellent in quietness and low power consumption can be realized. Moreover, since the piezoelectric pump can be easily reduced in thickness, it can sufficiently contribute to the reduction in size and thickness of, for example, a portable electronic device in which the cooling device according to the present invention is mounted.

  The piezoelectric pump has a common hole for introducing gas from the passage into the interior and ejecting the gas from the interior, a pump chamber driven by a piezoelectric body, and the hole across the passage It is preferable to comprise a wall body having discharge ports provided so as to face each other. By configuring the venturi nozzle with such a common hole and discharge port, it is possible to increase the flow rate due to the “breathing operation” of the piezoelectric pump.

  It is preferable that the gas introduction part has a recess with respect to the outer surface, and the inlet of the passage is provided at the bottom of the recess. This prevents the gas inlet of the passage from being blocked by water and sucking water from the outside through the gas inlet.

  The piezoelectric pump has an introduction hole for introducing gas into the inside from the passage and an ejection hole for ejecting gas from the inside to the outside, and includes a pump chamber driven by a piezoelectric body, It is preferable that the cooling device further includes a heat exchange element disposed on the passage. By providing the heat exchanger upstream of the gas flow path, the cooling efficiency can be increased.

  The piezoelectric pump is preferably driven at a frequency of 22 kHz or higher. As a result, the piezoelectric pump can be driven at a frequency outside the audible sound range, and the silence is excellent.

  The filter is preferably a waterproof breathable sheet in which a number of fine holes are formed in a highly water-repellent sheet material. The fine holes may be, for example, circular and have a diameter of 250 μm or less, more preferably 150 μm or less, and a waterproof ventilation sheet made of GORE-TEX (registered trademark) or the like may be used as the filter.

  If the filter is a waterproof breathable sheet with a lot of fine holes perforated in a highly water-repellent sheet material, the water droplets will be bead-shaped due to the water repellency of the sheet material and the surface tension of the water itself. Can't pass. On the other hand, since air can freely pass through fine holes, the function of passing air without passing water can be obtained. As a sheet-like material having high water repellency, for example, Teflon (registered trademark) can be used. For example, Gore-Tex (registered trademark) can be used as a filter, but by using a waterproof breathable sheet in which a large number of fine holes are formed in the above water-repellent sheet-like material, ventilation resistance and It is possible to design the waterproofness optimally. For example, when the suction pressure is high, the hole diameter can be reduced to prevent water from being sucked, and when the pressure is low, the hole diameter can be increased to reduce the airflow resistance. In addition, by using a thin sheet material as a filter material, the low profile of the piezoelectric pump is not impaired, and for example, it is advantageous for mounting on a portable electronic device.

  If the fine pores are about 150 μm or less, the water-resistant air-permeable sheet will have water droplets even if the suction pressure of the piezoelectric pump (which may be considered as static pressure) is as high as 2 kPa unless the entire surface of the water-proof air-permeable sheet is covered with water Never go through. This is because air passes through a portion where water droplets are not attached and releases pressure. On the other hand, a fine hole having a diameter of about 250 μm or less can be used only when the suction pressure of the piezoelectric pump is as low as 300 Pa or less. When the hole diameter is large, the ventilation resistance of the waterproof ventilation sheet is low, so that the performance degradation when using a piezoelectric pump with a low suction pressure can be reduced.

  In addition, since the ventilation resistance of the waterproof ventilation sheet is inversely proportional to the area of the area through which air can pass, the larger the area, the less the performance degradation. Therefore, ideally, it would be ideal if the entire mounting area of the piezoelectric pump could be used for the waterproof ventilation sheet. Since the piezoelectric pump has a space for driving the piezoelectric actuator, the maximum performance that can be realized by the area of the piezoelectric pump can be exhibited by adopting a configuration in which the area of this space can be used by the waterproof ventilation sheet. .

  The piezoelectric pump according to the present invention has a common hole for introducing gas into the inside from a passage for introducing gas from outside and ejecting the gas from inside, and is a pump chamber driven by a piezoelectric body And a wall body having a discharge port provided so as to face the hole across the passage and constituting the passage with the pump chamber.

  As described above, by configuring the venturi nozzle with the common hole and the discharge port, it is possible to increase the flow rate due to the “breathing operation” of the piezoelectric pump. Thereby, the performance as a piezoelectric pump can be improved. In addition, it contributes to thinning.

Preferably, the pump chamber includes a diaphragm to which the piezoelectric body is attached, and a pump main body that forms a pump chamber between the diaphragm and the hole provided on the side facing the diaphragm. Thereby, the piezoelectric pump can be thinned. The diameter of the discharge port is preferably larger than the diameter of the hole. As a result, the flow rate due to the “breathing operation” of the piezoelectric pump can be further increased.

  An electronic device according to the present invention has a gas introduction portion having a passage for introducing gas from the outside, and introduces gas from the outside through the passage, jets the gas from the inside, and is driven at a frequency outside the audible sound range. And a cooling device that is provided so as to block the passage, and that has a filter that passes at least gas but restricts passage of liquid, and an electronic component that is cooled based on the gas ejected from the piezoelectric pump It comprises.

  In the present invention, a filter for restricting the passage of the liquid is provided in the passage for introducing the gas from the outside to the piezoelectric pump so that the passage of the gas is restricted so that the passage of the liquid is blocked. Will be excellent in waterproofness. Also, since the piezoelectric pump has a high static pressure, even if the filter is provided in the passage for introducing gas from the outside to the piezoelectric pump, the suction force by the piezoelectric pump is not substantially reduced. Cooling can be performed efficiently. Furthermore, in the present invention, by providing the above-described filter, the chance of dust being sucked into the electronic device is drastically reduced, and the failure of the electronic device due to such dust is extremely reduced. Furthermore, by using a piezoelectric pump, it is possible to achieve excellent quietness and low power consumption. Moreover, since the piezoelectric pump can be easily reduced in thickness, it can sufficiently contribute to the reduction in size and thickness of the electronic device according to the present invention.

  The piezoelectric pump includes a pump chamber including a diaphragm to which the piezoelectric body is attached and a pump body that forms a pump chamber between the diaphragm and the hole provided on the side facing the diaphragm. The diaphragm is preferably used also as a speaker of the electronic device. Thereby, reduction of the number of parts of an electronic device can be aimed at.

  As mentioned above, according to this invention, it is excellent in waterproofness and can perform cooling efficiently.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an exploded perspective view of a main part showing a configuration of a portable electronic device according to an embodiment of the present invention, FIG. 2 is a sectional view including a microphone and a lens of the portable electronic device, and FIG. It is an external view. Here, a portable video camera is taken as an example of the portable electronic device, but a portable phone or other electronic device may of course be used.

  As shown in these drawings, in the portable video camera 1, the captured subject video is recorded / reproduced by the HDD unit 5 mounted in the housing 3 of the camera body 2.

  Here, in FIG. 3, 4 is a lens of the camera unit, 6 is a microphone for collecting sound during imaging, 7 is a display unit such as an LCD which is a monitor and finder pivotally attached to the camera body 2, and 8 Is an eyepiece unit, 9 is a group of operation buttons, and a cooling device 16 is disposed on the bottom 10 of the housing 3.

  The casing 5a of the HDD unit 5 is a metal part cast on the front side (the back side in FIG. 1) by aluminum die casting or the like, and the back side (the front side in FIG. 1) is composed of a printed circuit board for driving. With the part facing down, the heat transfer sheet 21a is joined to the heat transfer unit 20 having a high heat conductivity, such as a metal such as copper.

  The heat transfer unit 20 has a shape in which both ends of the strip-shaped copper plate are bent in opposite directions to each other, and a heat transfer sheet 21 a is joined to one bent piece 20 a and fixed to the HDD unit 5. The heat transfer sheet 21b is also joined to the other bent piece 20b, and the heat conduction sheet 21b is joined to the upper surface of the sealed casing 19, and the HDD unit 5 is fixed on the sealed casing 19 as shown in FIG. .

  The sealed casing 19 and the cooling device 16 are fixed to the bottom 10 of the housing 3 via screws 23. Accordingly, the heat heated to a high temperature by the HDD unit 5 is transmitted to the heat transfer unit 20, and this heat is cooled by the cooling device 16.

FIG. 4 is a cross-sectional view showing the configuration of the cooling device 16.
As shown in FIG. 4, the cooling device 16 includes flow paths 31 (introduction holes 25) provided at, for example, four locations on the bottom portion 10 (gas introduction portion) of the housing 3 in order to introduce gas from outside, A piezoelectric pump 32 that introduces gas from the outside through the flow path 31 and ejects the gas from the inside, and a filter 33 that is provided so as to close each flow path 31 and that allows gas to pass but restricts passage of liquid. It has.

FIG. 5 is an exploded perspective view of the piezoelectric pump 32.
As shown in FIGS. 4 and 5, the piezoelectric pump 32 includes a top plate 34 as a wall body, an insertion plate 35 for forming a flow path (passage) 31, and a top plate 37 of the pump chamber 36 in order from the top. , An insertion plate 38 for forming a space in the pump chamber 36, a diaphragm 39, a piezoelectric element 40 attached to the back surface of the diaphragm 39, and a protective ring 41.

  The top plate 34 has, for example, a substantially box shape, and a discharge port 42 is provided at the center of the top plate 34 for discharging the gas ejected from the piezoelectric pump 32 toward the bent piece 20b.

  The insertion plate 35 has a substantially rectangular shape, for example, and has a cross-shaped punching portion 43 in order to form the flow path 31. The venturi nozzle part is provided at a position corresponding to the discharge port 42, that is, at the center of the insertion plate 35 (intersection of the cross-shaped punching part 43).

  The top plate 37 of the pump chamber 36 has, for example, an octagonal shape in which square corners are cut off, for example. A portion 44 where each corner of these squares is cut off forms a flow path 31 with the inner wall of the top plate 34. The top plate 37 is provided with a hole 45 for introducing gas from the flow path 31 into the pump chamber 36 and for ejecting gas from the pump chamber 36 to the bent piece 20 b side through the discharge port 42. .

  The insertion plate 38 for forming the space in the pump chamber 36 also has the same shape as the top plate 37 described above, and the cut portion 46 forms the flow path 31 between the inner walls of the top plate 34. . The insertion plate 38 has a thickness for forming a space to some extent as the pump chamber 36.

  The diaphragm 39 also has the same shape as the top plate 37 described above, and the cut portion 47 forms the flow path 31 with the inner wall of the top plate 34. The protrusion 48 protruding in the horizontal direction from one side forms a wiring pattern to the piezoelectric element 40.

  The piezoelectric element 40 has a circular shape, for example, and vibrates according to an applied voltage (alternating voltage). FIG. 6 is a block diagram showing a schematic configuration of a control system of the piezoelectric element 40. The control unit 49 applies a voltage having a voltage value corresponding to the temperature detected by the temperature detection sensor 50 in the housing 3, for example. The power supply unit 51 is controlled so as to be applied to. The frequency of the applied voltage is preferably, for example, 22 kHz or more, which is a non-audible sound region, from the viewpoint of noise suppression.

  The protection ring 41 has the same shape as the top plate 37 and the like, and the cut-out portion 52 forms the flow path 31 with the inner wall of the top plate 34. The protective ring 41 has a thickness that prevents the diaphragm 39 and the piezoelectric element 40 from colliding with the bottom 10 of the housing 3 during the vibration due to the vibration of the piezoelectric element 40.

FIG. 7 is a sectional view of the filter 33.
As shown in FIG. 7, the filter 33 is a waterproof ventilation sheet in which a large number of fine holes 54 are formed in a highly water-repellent sheet-like material 53 such as Teflon (registered trademark). The fine holes 54 may be, for example, circular and have a diameter of 250 μm or less, more preferably 150 μm or less. Of course, a waterproof breathable sheet made of GORE-TEX (registered trademark) or the like may be used as the filter 33.

  When the above-described waterproof breathable sheet is used as the filter 33, the water droplets become ball-like due to the water repellency of the sheet-like material 53 and the surface tension of the water itself, and cannot pass through the sheet. On the other hand, since air can freely pass through the fine holes 54, the function of passing air without passing water is obtained. By using a waterproof breathable sheet in which a large number of fine holes 54 are formed in a highly water-repellent sheet-like material 53 as the filter 33, it is possible to optimally design ventilation resistance and waterproofness. For example, when the suction pressure is high, the hole diameter can be reduced to prevent water from being sucked, and when the pressure is low, the hole diameter can be increased to reduce the airflow resistance.

  If the fine holes 54 are about 150 μm or less, water droplets are waterproof at first even if the suction pressure of the piezoelectric pump 32 (which may be considered as static pressure) is as high as about 2 kPa unless the entire waterproof ventilation sheet is covered with water. It does not pass through the ventilation sheet. This is because air passes through a portion where water droplets are not attached and releases pressure. On the other hand, when the diameter of the fine hole 54 is about 250 μm or less, it can be used only when the suction pressure of the piezoelectric pump 32 is as low as 300 Pa or less. With a large hole diameter, the ventilation resistance of the waterproof ventilation sheet is low, so that the performance degradation when using the piezoelectric pump 32 with a low suction pressure can be reduced.

  Next, operation | movement of the cooling device 16 comprised in this way is demonstrated based on Fig.8 (a)-(e).

  FIG. 8A to FIG. 8E are diagrams for explaining the operation of the cooling device 16.

  In the state shown in FIG. 8A, by applying an alternating voltage to the piezoelectric element 40, the diaphragm 39 is bent and deformed as shown in FIG. 8B, and the volume of the pump chamber 36 is increased. As a result, outside air is introduced into the flow path 31 from the introduction hole 25 and taken into the pump chamber 36 through the hole 45.

  As shown in FIGS. 8C and 8D, the diaphragm 39 is bent and deformed, and the volume of the pump chamber 36 is reduced. Thereby, the air in the pump chamber 36 is ejected from the discharge port 42 through the hole 45. At this time, air in the flow path (passage) 31 is simultaneously ejected from the discharge port 42 by the venturi nozzle constituted by the hole 45 and the discharge port 42 to increase the flow rate. As a result, air is blown onto the sealed casing 19 shown in FIG. 2 to cool the HDD unit 5 via the heat transfer unit 20.

  As shown in FIG. 8E, the diaphragm 39 is bent and deformed, and the volume of the pump chamber 36 is increased again. As a result, outside air is again taken into the pump chamber 36 from the hole 45 through the flow path 31.

  In FIG. 8, the hole 45 and the discharge port 42 are separated. However, it may be configured by one continuous hole.

  As described above, according to the present embodiment, the flow path (passage) 31 of the cooling device 16 is provided with the filter 33 that restricts the passage of the liquid but the gas passes so as to block the flow path 31. There is no need to inhale, and the portable video camera 1 with excellent waterproofness can be obtained. Further, since the piezoelectric pump 32 has a high static pressure of about 2 kPa, the suction force by the piezoelectric pump 32 is not substantially reduced by the filter 33, and therefore cooling can be performed efficiently.

  By providing the filter 33, for example, the opportunity for dust to be sucked into the portable video camera 1 on which the cooling device 16 is mounted is drastically reduced, and failure of the portable video camera 1 due to such dust or the like can be reduced. Very little. Moreover, by using the piezoelectric pump 32, it is excellent in silence and low power consumption can be realized. Moreover, since the piezoelectric pump 32 can be easily reduced in thickness, it can sufficiently contribute to the reduction in size and thickness of the portable video camera 1, for example.

  The piezoelectric pump 32 has a common hole 45 for introducing gas into the flow path (passage) 31 and ejecting the gas from the inside, and a pump chamber 36 driven by the piezoelectric element 40, And a top plate 34 having a discharge port 42 provided so as to face the hole 45 across the passage (passage) 31. By configuring the venturi nozzle with the common hole 45 and the discharge port 42 as described above, it is possible to increase the flow rate due to the “breathing operation” of the piezoelectric pump.

  The diaphragm 39 may also be used as a speaker of the portable video camera 1, whereby cost and size and thickness can be reduced.

Next, an example of the cooling device 1 will be described.
(1) Volume (area, height) of the pump chamber 36
Diameter φ16mm
Height 0.15mm
(2) Area of air introduction hole from outside Diameter φ1.2 mm × 4 locations (3) Area of air outlet (discharge port 42, hole 45)
Pump chamber hole 45 diameter φ0.6mm
Discharge port 42 Diameter φ0.8mm
(4) Volume (area, height) of the entire cooling device 16
Area 20mm x 20mm
1.6mm height
(The height excluding the nozzle. The nozzle height when the nozzle is provided is 0.8 mm, and the total height is 2.4 mm.)
(5) The amplitude of the piezoelectric element 40 is about ± 6 μm. (6) The vibration frequency of the piezoelectric element 40 is about 24 kHz. (7) The material name, pore diameter, pore density, and thickness of the filter 33 Sunmap LC-T (Nitto Denko Trade name of high molecular weight polyethylene porous film)
Average pore size 17μm
Porosity 25%
Thickness 0.1mm
Air permeability 1.4sec / 100cm2
(8) Impedance of filter 33 about 0.9 kPa / (L / min) (when used in the region of φ16 mm, value converted from air permeability of 1.4 sec / 100 cm 2)
(9) Static pressure 2kPa
(10) The flow rate is 1.0 L / min.

  FIG. 9 is a diagram showing operating characteristics of the piezoelectric pump 32, and FIG. 10 is a diagram comparing operating characteristics of the piezoelectric pump 32 and the axial fan.

  These figures show the case where the static pressure of the piezoelectric pump 32 is 1.2 kPa and the maximum flow rate is 20 cc / s, and the static pressure of the axial fan (commercial product) is 0.04 kPa and the maximum flow rate is 2500 cc / s. .

  It shows that the operating point of the piezoelectric pump 32 is 10 cc / s or more, whereas the axial fan (commercial product) is 1 cc / s or less.

  The air permeability of the waterproof breathable filter (sheet) is 1.4 sec / 100 cm3, which is measured by the Gurley method (passing time of 100 cc3 of air when a differential pressure of 1.23 kPa is applied to an area of 6.42 cm2. Is a value obtained in (Measurement).

  When the airflow resistance is small (that is, when the air flows freely through the housing 3 → actually difficult), the axial flow fan (fan motor) can obtain a larger flow rate, but the filter 33 (waterproof airflow filter) (Sheet)) (or in a state where the air hardly flows in the housing 3), the axial flow fan cannot obtain a flow rate at all, and unless the piezoelectric pump 32 (blower) is used, the cooling effect is obtained. Can't get.

  A cooling device 1 'according to another embodiment of the present invention will be described. In this embodiment and subsequent embodiments, the same components as those in the above-described embodiment will be denoted by the same reference numerals, description thereof will be omitted, and different points will be mainly described.

FIG. 11 is a partial cross-sectional view of a portable electronic device in which a cooling device according to another embodiment is installed.
As shown in FIG. 11, a cooling device 16 ′ having a filter 33 ′ provided at a position different from the filter 33 is provided.

  The filter 33 ′ is composed of the same components as the filter 33, and is provided on the inner surface of the housing 3 over substantially the same area as the area of the sealed casing 19. The filter 33 ′ is provided so as to block the gas inlet 17 and the outlet 18 of the housing 3. The introduction hole 25 of the cooling device 16 ′ (see FIG. 4) corresponds to the introduction port 17.

  According to such a configuration, by driving the piezoelectric element 40 of the cooling device 16 ′, outside air is taken into the sealed casing 19 from the introduction port 17 in the direction of the arrow, and gas is discharged to the outside through the discharge port 18. Sometimes, the filter 33 ′ can prevent water droplets from being sucked into the housing 3 and water droplets from flowing into the discharge port 18.

  Since the filter 33 ′ is provided on the inner surface of the housing 3 over almost the same area as the area of the hermetic casing 19, it is possible to improve the vibration isolation of the cooling device 16 ′. Since the filter 33 ′ is provided on the inner surface of the housing 3 over almost the same area as the sealed casing 19, the inlet 17 and the outlet 18 can be reliably and easily closed.

FIG. 12 is a partial cross-sectional view of a portable electronic device in which a cooling device according to another embodiment is installed.
This embodiment is different from FIG. 11 in that the outer surface 3 </ b> A of the housing 3 has a recess 55 and the introduction port 17 of the flow path 31 is provided at the bottom of the recess 55. In such a configuration, the gas inlet 17 of the flow path 31 is not blocked by water and water is not sucked from the outside through the gas inlet 17.

FIG. 13 is a partial cross-sectional view of a portable electronic device in which a cooling device according to another embodiment is installed.
As shown in FIG. 13, a cooling device 16 that ejects air to the CCD 14, an introduction portion 60 that introduces gas into the cooling device 16, and a filter 33 that prevents water droplets or the like from flowing into the introduction portion 60 are provided. ing.

  The cooling device 16 is provided in the introduction part 60 so that gas can be ejected from the discharge hole 42 to the CCD 14.

  The introduction unit 60 includes a flow path 61 that guides gas from the outside to the introduction hole of the flow path 31 of the cooling device 16, a communication hole 62 that communicates with the introduction hole of the flow path 31 of the cooling device 16, and the flow path 61. An opening 63 formed in the housing 3 is provided for introducing outside air.

  The filter 33 is provided so as to close the opening 63 of the flow path 61 of the introduction part 60.

  According to such a configuration, the CCD 14 and the like can be directly cooled, and at this time, the filter 33 can prevent water droplets from flowing in from the outside.

FIG. 14 is a partial cross-sectional view of a portable electronic device in which a cooling device according to another embodiment is installed.
A heat exchange portion 57 is provided at a position corresponding to the heat transfer sheet 21 b, and a cooling device 56 that discharges the air in the sealed casing 19 to the outside next to the heat exchange portion 57.

  The heat exchanging portion 57 is a heat sink or the like to be described later that is introduced into the sealed casing 19 from the introduction hole 25 through the filter 33 and cools the heat transfer sheet 21b.

  The cooling device 56 is disposed in the housing 3 with the discharge port 42 (see FIG. 4) side facing the housing 3 side. The ejection port 42 and the ejection hole 26 of the housing 3 are aligned so that the air ejected from the ejection port 42 is ejected to the outside. The filter 33 may be inserted into the ejection hole 26.

  According to such a configuration, by driving the cooling device 56, outside air is introduced into the sealed casing 19 from the introduction hole 25 through the filter 33, and air in the sealed casing 19 is introduced through the discharge port 42. It can be ejected from the ejection hole 26 to the outside. At this time, a gas flow is generated in the direction of the arrow in the hermetic casing 19, and the HDD unit 5 can be cooled by taking the heat of the HDD unit 5 through the heat transfer unit 20 or the like by the heat exchange unit 57. That is, the HDD unit 5 can be cooled using the heat exchanging unit 57 without blowing the air discharged from the cooling device 56 directly onto the sealed casing 19.

FIG. 15 is a cross-sectional view showing an example of the heat exchange section 57 (57a to 57e).
As shown in FIG. 15A, the heat exchanging portion 57a includes a heat sink 58a having a comb-shaped cross section and a cover 59 covering the heat sink 58a. The heat sink 58a is provided, for example, so that gas passes through the recess from the introduction hole 25 side to the ejection hole 26 side.

  As shown in FIG. 15B, the heat exchanging portion 57b includes a heat sink 58b having a meandering cross section and a cover 59 covering the heat sink 58b.

  As shown in FIG. 15C, the heat exchanging portion 57c includes a heat sink 58c having a concavo-convex cross section and a cover 59 that covers the heat sink 58c.

  As shown in FIG. 15D, the heat exchanging portion 57d includes a heat sink 58d having a bellows cross section and a cover 59 that covers the heat sink 58d.

  As shown in FIG. 15E, the heat exchanging portion 57e includes a heat sink 58e having a plurality of cross-sectional through holes 58g and a cover 59 that covers the heat sink 58e. The through hole 58 is formed, for example, so that gas passes from the introduction hole 25 side to the ejection hole 26 side.

  As shown in these drawings, the heat sinks 58a to 58e are made of a metal such as aluminum, for example.

FIG. 16 is a partial cross-sectional view of a portable electronic device in which a cooling device according to another embodiment is installed.
The cooling device 66 shown in FIG. 16 differs from the cooling device 56 shown in FIG. 14 in the position where the filter 65 is disposed.

  The filter 65 is disposed on the inner surface of the housing 3 so as to cover a mounting area substantially the same as that of the sealed casing 19. The filter 65 is disposed so as to block the introduction hole 25 and the ejection hole 26. The filter 65 is made of the same material as that of the filter 33.

  According to such a configuration, heat from the HDD unit 5 and the like can be radiated and water droplets can be prevented from flowing into the sealed casing 19 from the introduction hole 25 and the ejection hole 26.

  When both the sealed casing 19 and the housing 3 are made of metal, they are thermally insulated to some extent by the filter 65, so that heat is not directly transmitted to the housing 3, and the housing 3 is not easily heated.

  When the sealed casing 19 is made of metal and the casing 3 is made of resin, even if the sealed casing 19 is heated, the casing 3 is made of resin and heat is hardly transmitted.

FIG. 17 is a partial cross-sectional view of a portable electronic device in which a cooling device according to another embodiment is installed.
This embodiment is an example in which the sealed casing 19 is made of resin in FIG.
As shown in FIG. 17, compared with FIG. 14, a sealed casing 19 ′ in which an insertion hole 19 a is formed, and a heat exchange unit 57 ′ connected to the heat transfer unit 20 through a heat transfer sheet 21 b are provided. Yes.

  The sealed casing 19 ′ has an insertion hole 19a, and the top of the heat exchange part 57 ′ is inserted into the insertion hole 19a. The top of the heat exchanging part 57 ′ is connected to the heat transfer part 20 without passing through the heat transfer sheet 21b.

  According to such a configuration, even if the sealed casing 19 ′ is made of resin, the heat of the HDD unit 5 can be radiated to the outside of the housing 3 by the heat exchange part 57 ′ via the heat transfer sheet 21 b. . At this time, since heat is radiated by the heat exchanging portion 57 ′, heat is not easily transmitted to the housing 3. Therefore, the housing 3 may be made of resin or metal.

  FIG. 18 is a cross-sectional view showing an example of the heat exchange section of FIG.

  As shown in FIG. 18, the heat exchanging unit 57 ′ includes a heat sink 58 ′ connected to the heat transfer unit 20 and a sealed casing 19 ′ that supports and accommodates the heat sink 58 ′.

  The heat sink 58 'has a connection part 58A connected to the heat transfer part 20 and a convex part 58B having a substantially comb shape, and the connection part 58A is supported by the sealed casing 19'. The plurality of convex portions 58B are arranged so that the gas passing through the concave portions between the convex portions 58B is directed from the introduction hole 25 toward the ejection hole 26.

  According to such a configuration, the heat of the heat transfer part 20 can be radiated from the convex part 58B via the connection part 58A of the heat sink 58 ′, and the HDD unit 5 can be efficiently cooled.

FIG. 19 is a cross-sectional view illustrating a configuration of a portable electronic device in which another cooling device is arranged.
As shown in FIG. 19, the cooling device 16 </ b> A is provided via the introduction holes 25 provided at, for example, two places on the bottom portion 10 (gas introduction portion) of the housing 3 and the respective flow paths 31 in order to introduce gas from the outside. A piezoelectric pump 32 ′ that introduces a gas from the outside and ejects the gas from the inside, and a filter 33 A that is provided so as to close each flow path 31 and that allows the gas to pass but restricts the passage of the liquid.

20 is an exploded perspective view of the piezoelectric pump 32 'shown in FIG.
As shown in FIGS. 19 and 20, the piezoelectric pump 32 ′ includes, in order from the top, a top plate 34 ′ as a wall body, an insertion plate 35 ′ for forming a flow path (passage) 31, and a pump chamber 36 ′. A top plate 37 ', an insertion plate 38' for forming a space in the pump chamber 36 ', a diaphragm 39', a piezoelectric element 40 attached to the back surface of the diaphragm 39 ', and a protective ring 41'. .

  The insertion plate 35 ′ has, for example, a rectangular frame shape. The venturi nozzle portion is provided at a position corresponding to the discharge port 42, that is, at the center of the insertion plate 35 '(intersection of the frame holes).

  The top plate 37 ′ of the pump chamber 36 ′ has, for example, a hexagonal shape in which a pair of opposite corners of a square are cut off, for example. The portion 44 from which the two corners of these squares are cut out forms a flow path 31 with the inner wall of the top plate 34 '.

  An insertion plate 38 ′ for forming a space in the pump chamber 36 ′ has the same shape as the top plate 37 ′.

  The diaphragm 39 ′ also has the same shape as the top plate 37 ′, and the cut-out portion 47 forms the flow path 31 with the inner wall of the top plate 34 ′.

  The protection ring 41 'is formed with a cutting portion 41A.

  The filter 33A is provided on the convex portion 68 provided on the housing 3 so as to be separated from the housing 3 so that the mounting area of the cooling device 16A is substantially the same. As described above, the filter 33A is a waterproof ventilation sheet in which a large number of fine holes 54 are formed in a highly water-repellent sheet material 53 such as Teflon (registered trademark). Of course, as the filter 33A, a waterproof ventilation sheet made of GORE-TEX (registered trademark) or the like may be used.

  As shown in FIG. 19, when the piezoelectric element 40 is driven and the space in the pump chamber 36 ′ increases, external air is introduced into the flow path 31 from the introduction hole 25, and the pump chamber 36 ′ through the hole 45. Flows into the interior space. At this time, the air introduced from the introduction hole 25 flows into the protective ring 41 ′ side through the filter 33A having the same area as the mounting area of the cooling device 16A as indicated by an arrow, and flows into the flow path 31 through the cutting portion 41A. Flow into. When the piezoelectric element 40 is driven and the space in the pump chamber 36 ′ becomes small, the air flowing into the space in the pump chamber 36 ′ is ejected to the outside of the top plate 34 ′ through the discharge port 42.

  According to such a configuration, the air introduced from the introduction hole 25 flows into the protective ring 41 ′ side through the filter 33A having the same area as the mounting area of the cooling device 16A as shown by the arrow in FIG. It flows into the flow path 31 through the portion 41A. Therefore, air can be efficiently introduced.

  Since the entire mounting area of the piezoelectric pump 32 ′ can be used for the filter 33 </ b> A, the ventilation resistance of the filter 33 </ b> A can be reduced and the performance of the cooling device 16 </ b> A can be prevented from being lowered. Since the piezoelectric pump 32 ′ has a space for driving the piezoelectric element 40, the maximum performance that can be realized by the area of the piezoelectric pump 32 ′ is exhibited by adopting a configuration in which the area of this space can be used by the filter 33 </ b> A. be able to.

FIG. 21 is a cross-sectional view showing a configuration of a portable electronic device in which another cooling device is arranged.
As shown in FIG. 21, the cooling device 16 </ b> B introduces gas from the outside through the introduction hole 25 provided in the bottom 10 (gas introduction part) of the housing 3 and the introduction hole 25 in order to introduce gas from the outside. A piezoelectric pump 32A that introduces and ejects gas from the inside, and a filter 33 that is provided so as to block the introduction hole 25 and the flow path 31 and that allows gas to pass but restricts passage of liquid.

FIG. 22 is an exploded perspective view of the piezoelectric pump 32A shown in FIG.
As shown in FIGS. 21 and 22, the piezoelectric pump 32A includes a top plate 34 'as a wall body, an insertion plate 35A for forming a flow path (passage) 31, and a top plate of the pump chamber 36A in order from the top. 37A, an insertion plate 38A for forming a space in the pump chamber 36A, a diaphragm 39 ', a piezoelectric element 40 attached to the back surface of the diaphragm 39', and a protective ring 41B.

  The insertion plate 35A has, for example, a substantially rectangular plate shape, a hole 35b is formed at a corner to form the flow path 31, a hole 35a is formed at the center, and the holes 35a and 35b are linear holes. 35c. The hole 35 b forms the flow path 31. The venturi nozzle portion is provided at a position corresponding to the discharge port 42, that is, at the center of the insertion plate 35.

  The top plate 37A of the pump chamber 36A has, for example, a rectangular shape. A hole 37B is formed at a position corresponding to the hole 35b. This hole 37 </ b> B forms a flow path 31. The top plate 37A is provided with a hole 45 for introducing gas from the flow path 31 into the pump chamber 36A and for ejecting gas from the pump chamber 36A through the discharge port 42 to the bent piece 20b side. .

  An insertion plate 38A for forming a space in the pump chamber 36A also has the same shape as the top plate 37A. In the top plate 37A, a hole 38B is formed at a position corresponding to the hole 37B. A channel 31 is formed by the hole 38B. The insertion plate 38A has a thickness for forming a space to some extent as the pump chamber 36A.

  The protection ring 41B has the same shape as the above-described insertion plate 38A and the like, and the three cut portions 52 and the cutting portion 41C form the flow path 31 between the inner wall of the top plate 34 '. The protective ring 41B has a thickness that prevents the diaphragm 39 'and the piezoelectric element 40 from colliding with the bottom 10 of the housing 3 during vibration due to the vibration of the piezoelectric element 40.

  According to such a configuration, by driving the piezoelectric element 40, outside air is taken into the flow path 31 from the introduction hole 25, and air is introduced into the pump chamber 36A via the hole 35b, the linear hole 35c, the hole 35a, and the hole 45. Can be imported. At this time, the filter 33 can prevent water droplets or the like from entering the housing 3.

FIG. 23 is a cross-sectional view illustrating a configuration of a portable electronic device including another cooling device.
As shown in FIG. 23, the portable video camera 1 ′ includes a cooling device 16C including a filter 33B instead of the cooling device 16B shown in FIG.

  The filter 33B of the cooling device 16C is disposed on the inner surface of the housing 3 so as to cover a mounting area substantially similar to the top plate 34C. The filter 33B is disposed so as to close the introduction hole 25. The filter 33B is made of the same material as that of the filter 33. A cooling device 66 is disposed on the filter 33B. The top plate 34 'has a flange portion 34F, and the flange portion 34F is screwed at a plurality of locations.

  According to such a configuration, an anti-vibration effect can be obtained by the filter 33B. In addition to the filter 33B, another vibration-proof sheet may be disposed between the filter 33B and the housing 3. In this case, an opening may be formed at a position corresponding to the introduction hole 25.

FIG. 24 is a cross-sectional view illustrating a configuration of a portable electronic device including another cooling device.
As shown in FIG. 24, the portable video camera 1B includes a cooling device 16D including a filter 33C instead of the cooling device 16C shown in FIG. The filter 33C of the cooling device 16D is disposed on the inner surface of the housing 3 so as to cover a mounting area substantially the same as that of the top plate 34D. The filter 33C is disposed so as to close the introduction hole 25.

  A claw portion 82 is formed on the inner surface side of the housing 3, and one end portion of the top plate 34 </ b> D, one end portion of the filter 33 </ b> C, and the vibration isolating sheet 81 are sandwiched between the claw portions 82. The other end of the top plate 34D is screwed to the housing 3 via the other end of the filter 33C.

  According to such a configuration, it is possible to prevent water droplets or the like from entering the cooling device 16D by the filter 33C, and to obtain a vibration isolation effect by the filter 33C and the vibration isolation sheet 81. Further, the claw portion 82 can easily align the flow path 31 of the cooling device 16 </ b> D and the introduction hole 25 of the housing 3. In addition, the number of parts such as screws can be reduced and the cost can be reduced.

FIG. 25 is a cross-sectional view illustrating a configuration of a portable electronic device including another cooling device.
As shown in FIG. 25, the portable video camera 1C includes a cooling device unit 16U.

  The cooling device unit 16U is configured to be detachable from the housing 3 with, for example, screws. The cooling device unit 16U includes a cooling device 16C illustrated in FIG. 23 and a substrate 86 including a claw portion 85.

  The flange portion 34F of the top plate 34 'of the cooling device 16C and both end portions of the filter 33B are sandwiched between the claw portions 85, respectively.

  According to such a configuration, the cooling device unit 16U can be removed from the housing 3, and the inside of the cooling device 16C and the portable video camera 1C can be easily maintained.

  The present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the technical idea of the present invention.

It is a principal part disassembled perspective view which shows the structure of the portable electronic device which concerns on one Embodiment of this invention. It is sectional drawing including the microphone and lens of a portable electronic device. It is an external view of an electronic device. It is sectional drawing which shows the structure of a cooling device. It is a disassembled perspective view of a piezoelectric pump. It is a block diagram which shows schematic structure of the control system of a piezoelectric element. It is sectional drawing of a filter. It is a figure for demonstrating operation | movement of a cooling device. It is a figure which shows the operating characteristic of a piezoelectric pump. It is a figure which compares the operating characteristic of a piezoelectric pump and an axial flow fan. It is a fragmentary sectional view of the portable electronic device with which the cooling device of other embodiment was installed. It is a fragmentary sectional view of the portable electronic device with which the cooling device of other embodiment was installed. It is a fragmentary sectional view of the portable electronic device with which the cooling device of other embodiment was installed. It is a fragmentary sectional view of the portable electronic device with which the cooling device of other embodiment was installed. It is sectional drawing which shows the example of a heat exchange part. It is a fragmentary sectional view of the portable electronic device with which the cooling device of other embodiment was installed. It is a fragmentary sectional view of the portable electronic device with which the cooling device of other embodiment was installed. It is sectional drawing which shows an example of the heat exchange part of FIG. It is sectional drawing which shows the structure of the portable electronic device by which another cooling device is arrange | positioned. It is a disassembled perspective view of the piezoelectric pump shown in FIG. It is sectional drawing which shows the structure of the portable electronic device by which another cooling device is arrange | positioned. It is a disassembled perspective view of the piezoelectric pump shown in FIG. It is sectional drawing which shows the structure of the portable electronic device provided with another cooling device. It is sectional drawing which shows the structure of the portable electronic device provided with another cooling device. It is sectional drawing which shows the structure of the portable electronic device provided with another cooling device.

Explanation of symbols

1, 1 ', 1B, 1C Portable video camera 3 Housing 3A External surface 10 Bottom 16, 16A, 16B, 16C, 16D, 56, 66 Cooling device 25 Introduction hole 31 Passage 32 Piezoelectric pump 33, 33', 33B, 33C Filter 34 Top plate 36 Pump chamber 40 Piezoelectric element 42 Ejection port 45 Hole 55 Recess 25 Inlet hole 17 Ejection hole 53 Sheet material 54 Hole 57, 57a, 57b, 57c, 57d, 57e Heat exchange part

Claims (11)

A gas introduction part having a passage for introducing gas from the outside;
A piezoelectric pump that introduces gas from the outside through the passage and ejects the gas from the inside;
A cooling device comprising: a filter provided so as to close the passage, wherein at least gas passes but restricts passage of liquid. The cooling device according to claim 1,
The piezoelectric pump is
A pump chamber that introduces gas from the passage into the interior and has a common hole for ejecting the gas from the interior, and is driven by a piezoelectric body;
And a wall body having a discharge port provided so as to face the hole with the passage interposed therebetween. The cooling device according to claim 1,
The gas introduction part has a recess with respect to the external surface;
A cooling device in which an inlet for the passage is provided at the bottom of the recess. The cooling device according to claim 1,
The piezoelectric pump has an introduction hole for introducing gas into the inside from the passage and an ejection hole for ejecting gas from the inside to the outside, and includes a pump chamber driven by a piezoelectric body,
The cooling device further includes a heat exchanger disposed on the passage. The cooling device according to claim 1,
The piezoelectric pump is a cooling device that is driven at a frequency of 22 kHz or more. The cooling device according to claim 1,
The cooling device is a cooling air-permeable sheet in which a large number of fine holes are formed in a highly water-repellent sheet material. A pump chamber driven by a piezoelectric body, having a common hole for introducing gas into the inside from a passage for introducing gas from outside and ejecting gas from the inside;
A piezoelectric pump comprising: a discharge port provided so as to face the hole across the passage, and a wall constituting the passage with the pump chamber. The piezoelectric pump according to claim 7,
The pump chamber is
A diaphragm to which the piezoelectric body is attached;
A piezoelectric pump comprising: a pump body which forms a pump chamber with the diaphragm and has the hole provided on a side facing the diaphragm. The piezoelectric pump according to claim 7,
A piezoelectric pump in which a diameter of the discharge port is larger than a diameter of the hole. A gas introduction section having a passage for introducing gas from outside, a piezoelectric pump for introducing gas from outside through the passage, ejecting gas from inside, and driving at a frequency outside the audible sound range; and the passage A cooling device having a filter that is provided so as to be closed and at least allows gas to pass but restricts passage of liquid;
An electronic device comprising: an electronic component that is cooled based on gas ejected from the piezoelectric pump. The electronic device according to claim 10,
The piezoelectric pump is
A pump chamber having a pump body formed between the diaphragm to which the piezoelectric body is attached and the diaphragm, and a pump body provided with the hole on the side facing the diaphragm;
The diaphragm is an electronic device that is also used as a speaker of the electronic device.

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