JPH0635515Y2 - Cooling device for electric parts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cooling device for electric parts such as a cathode ray tube, a rectifier, and a transistor.

It is unavoidable that heat is generated during use in the electric parts as described above, and if the temperature rises excessively, it will have an adverse effect on the material or operating characteristics of itself or peripheral devices. Therefore, in addition to devising the heat dissipation structure for these electric parts, forced cooling by a cooling fan is also used. Conventionally, as a cooling fan, an electromagnetic motor drive type has been widely used. However, the lines of magnetic force generated from the electromagnetic motor are
Such an electromagnetic motor drive type cooling fan is not always preferable as a cooling means for electric parts because it may adversely affect the operating characteristics of the electric parts to be cooled or its peripheral devices such as deflection of electron beam in a cathode ray tube. . Further, the cooling fan driven by the electromagnetic motor causes a lot of noise and resonates the cooled electric component itself or its peripheral devices, and this also adversely affects the operating characteristics.

An object of the present invention is to provide a device structure suitable for efficiently cooling electric parts by using a bimorph fan that does not have such a problem.

That is, usually, a bimorph fan is obtained by fixing one end of a bimorph diaphragm, which is formed by laminating a plurality of piezoelectric films having different characteristics that expand or contract by applying a voltage and sandwiching the piezoelectric films between electrodes. By applying an AC voltage between the electrodes, the diaphragm vibrates alternately in opposite directions with the fixed portion as a fulcrum, and the wind can be sent to the object to be cooled by a motion similar to a fan. However, since the electric device that accommodates the cooled parts is required to be more and more compact, how to fix the bimorph fan in the limited space as an electric device cooling device and effectively generate the wind. It is also important to send the generated wind to the cooled parts. In addition, a certain type of bimorph is not necessarily good in heat resistance because it is made of a polymer piezoelectric film or a ceramic ferroelectric material having a low Curie point. Therefore, it may be necessary to perform effective cooling while preventing its deterioration due to heat. is there. As a result of diligent study on the above problems, the present inventors have fixed the bimorph fan in a cylinder having an air intake at an appropriate position, and fixed the cylinder to the wind tunnel and the bimorph fan. It was found that an efficient cooling device for electric parts can be obtained by using it as a means. The cooling device for electric parts according to the present invention is based on such knowledge. More specifically, the cooling device has a cylindrical body that opens toward an electric component to be cooled, and the electric body that is housed in the cylindrical body. A bimorph diaphragm that is fixed to the cylindrical body and extends substantially parallel to the axial direction of the cylindrical body at the end opposite to the component, and at least a bimorph diaphragm is provided in a portion of the cylindrical body that surrounds the bimorph diaphragm. It is characterized in that air suction ports are formed in side wall portions of the diaphragm that face each other in both directions.

Hereinafter, the device of the present invention will be described in more detail with reference to embodiments.

FIG. 1 is a perspective view of a preferred embodiment of the cooling device of the present invention. This device accommodates a bimorph diaphragm 2 extending substantially parallel to the axial direction in a rectangular cylinder 1 having an opening 1a toward an electric component to be cooled (not shown) located diagonally to the left, and The fixing portion of the bimorph diaphragm 2 or the upper and lower end surfaces of the electrical connecting portion 3 are bonded and fixed to the upper and lower surfaces of the rectangular tube 1. The fixing position of the bimorph diaphragm 2 in the rectangular tube 1 made of any material such as plastic or metal is near the end opposite to the opening 1a. An opening 1b serving as an air suction port is provided at the end of the rectangular tube 1 opposite to the opening 1a.
Are provided, and openings 4a and 4b are provided on the left and right side walls (that is, side walls substantially parallel to the bimorph 2) of the portion of the rectangular tube 1 that surrounds the bimorph diaphragm 2, and openings 5a and 4b are provided on the upper and lower side walls, respectively. 5b is provided. The connecting portion 3 of the bimorph diaphragm is connected to an AC power source (not shown) by lead wires 6a and 6b.

The operation of the above device will be described. When an AC voltage is applied to the polymer piezoelectric film in the bimorph 2 via the leads 6a, 6b and the connecting portion 3, the bimorph 2 vibrates left and right with the fixed portion 3 as a fulcrum, which causes the openings 1b, 4a, 4b and The air is blown out from the openings 5a and 5b and blows out the air in the direction A from the opening 1a. This wind forces the intended electrical components to be air-cooled.

It is not effective to provide only the opening 1b as the air intake port without providing the opening in the side wall of the rectangular tube 1. By the way, in the apparatus of the shape shown in FIG. 1, six polyvinylidene fluoride piezoelectric films (three pairs) having a thickness of 30 μ are sandwiched between the Al films having a thickness of 400 to 500 Å for each pair as a vibration plate. On a bimorph diaphragm that is adhesively laminated (movable part is 25 mm wide and 30 mm long rectangle),
A blow test was conducted by applying an alternating voltage of 49 Hz and 250 V. At this time, the air suction port is (a) only the opening 1b, (b) opening 4a, 4
For b only, (c) openings 5a and 5b only, and (d) openings 1b, 4a, 4b and 5a, 5b all (all openings are about 25 mm x 30 mm), measured at a position about 20 mm from the opening 1a The wind speeds are (a) 1.4 m / sec, (b) 1.8 m / sec, (c) 2.1 m /, respectively.
Seconds, (d) 2.3 m / sec. From this result, it can be seen that the openings 5a and 5b provided in the side wall portion surrounding the bimorph 2, particularly in the side wall portion substantially orthogonal to the bimorph 2, contribute particularly effectively as the air suction port.

In addition, in order to determine the effect of using the casing 1, the above-mentioned bimorph fan (maximum amplitude 25 mm) is used, and
When not using, and a cylinder body 1 of 30 mm × 30 mm × 50 mm
When using (apertures 1a, 1b, 4a, 4b, 5a, 5b are about 30 mm x about 30 mm, the distance between the tip of the bimorph diaphragm and the opening 1a is 20 mm), the wind speed changes with the distance from the tip of the bimorph 2. The change was measured. The results are as shown in the graph of FIG. 2, and it can be seen that the use of the cylindrical body makes it difficult for the wind speed to remarkably decrease even if the distance from the tip of the bimorph increases.

As described above, among the side wall openings of the cylindrical body, the side wall openings 5a and 5b orthogonal to the bimorph diaphragm have a more essential meaning. The tip of the diaphragm movable portion is located on the side opposite to the electrical component side with respect to the virtual surface (which is almost orthogonal to the side wall) passing through the side of the opening 5a, 5b located on the electrical component side to be cooled. And 0 to 10 mm from the virtual surface, especially 0 to
The range of 2 mm is preferable for improving the blowing efficiency. On the other hand, of the side wall opening of the cylindrical body, the portion closer to the fixed portion of the bimorph diaphragm does not contribute much to the air suction, and therefore its position is relatively arbitrary. Left and right side wall openings 4
The tip positions of a and 4b are relatively arbitrary as compared with the openings 5a and 5b.

The width of the vibration of the vibrating plate of the cylinder 1 is 10 times that of the vibrating plate 2.
It is preferably 0 to 200%, and particularly preferably 105 to 130%.

Although the preferred embodiment of the cooling device of the present invention has been described above, it will be easily understood by those skilled in the art that various modifications can be made within the scope of the present invention. The following illustrates some of these modifications.

First, the tubular body 1 is preferably a rectangular tube in terms of efficiency because the bimorph 2 moves reciprocally, but for example, the bimorph 2 has an arc-shaped tip, so that the bimorph 2 may have a cylindrical shape. It is possible to reduce the decrease in the efficiency of air blowing. Such a cylindrical shape is desirable in terms of manufacturing efficiency. Further, depending on the position of the electric component to be cooled, the cylindrical body 1 may be a curved cylinder bent in the extension direction instead of the straight cylinder. In this case, of course, the bimorph 2 is provided substantially parallel to the axis of the cylinder at the position where it is provided.

As shown in Fig. 1, the openings forming the air intake ports are 1b, 4
Although it can be provided at all positions of a, 4b and 5a, 5b, 4a,
It may be either 4b or 5a, 5b, or one of these.

As a method of fixing the fixing portion 3 of the bimorph 2 to the cylindrical body 1, in addition to the above-mentioned adhesion, a groove is cut at a pair of predetermined portions of the cylindrical body 1 and the upper and lower ends of the fixing portion 3 are inserted into the groove. Any fixing method can be adopted.

In this specification, the term "bimorph" is used in the broadest sense, and includes not only a bimorph made of a polymeric piezoelectric film but also a bimorph made of a ceramic piezoelectric film. That is, at least two layers of thin film bodies each having at least one piezoelectric film forming a bimorph are bonded with an adhesive, and the piezoelectric film of at least one layer is sandwiched, and an electrode film is arranged so that a voltage is applied to the piezoelectric film. (Refer to Japanese Patent Application No. 57-22389, if necessary, for specific examples of the bimorph laminated structure expressed in this way). In particular, when a bimorph made of a piezoelectric polymer film is used, there is a feature that noise is further reduced.

Further, the number of bimorphs in the cooling device is not limited to one, and two or more may be used. For example, the third
FIG. 2A is a schematic plan view for relatively showing the positions of the cylindrical body 1, the bimorph 2 and the fixing portion 3 thereof in the apparatus of FIG. 1, but in the case of using such a single bimorph Besides, correspondingly, FIG. 3 (b) and (c)
As shown in FIG. 2, two or more bimorphs 2 are arranged in parallel (FIG. 3 (b)), or the end of the tubular body 1 on the side opposite to the side of the electric component to be cooled has two or more branch barrels 11a, 11b (branch angle θ is preferably 90 ° or less), and the bimorphs 2 are housed in each of them (Fig. 3 (c)), so that the output power is higher than that in Fig. 1 (b). Can be enhanced. In this case, the output gradually increases in the order of FIG. 3 (a), FIG. 3 (b), and FIG. 3 (c). Further, in the arrangement of FIG. 3 (b), the vibration phases of two or more bimorphs 2 are aligned (that is, they vibrate substantially in parallel).
Is desirable from the viewpoint of output.

As described above, according to the present invention, the bimorph fan is housed in the cylinder serving as the wind tunnel by providing the opening at an appropriate position and is fixed to the cylinder, thereby efficiently generating and generating the wind. It is possible to spray the electric component to be cooled with good directivity and to forcibly cool it without damaging the wind. As a result, particularly for electric components that generate a large amount of heat, it becomes possible to perform effective cooling while relatively protecting the bimorph fan, which itself has poor heat resistance, from heat.

[Brief description of drawings]

FIG. 1 is a perspective view of a cooling device according to an embodiment of the present invention,
FIG. 2 is a graph showing the state of wind speed attenuation with the change of the distance from the fan depending on the presence or absence of the cylinder, and FIG. 3 shows various modes of the relative arrangement of the cylinder and the bimorph diaphragm in the cooling device of the present invention. It is a schematic plan view. 1 ... Cylinder body (11a, 11b ... Branching cylinder), 1a ... Opening facing electric parts, 1b ... End opening forming air blowing port, 2 ...
… Bimorph diaphragm, 3 …… Fixed part or electrical connection part of the diaphragm, 4a, 4b, 5a, 5b …… Side wall opening that forms the air inlet, 6
a, 6b …… Lead wire, A …… Wind blowing direction.

Claims (6)

[Scope of utility model registration request] 1. A cylindrical body opening toward an electric component to be cooled,
A bimorph diaphragm that is housed in the tubular body and extends substantially parallel to the axial direction of the tubular body fixed to the tubular body at an end of the tubular body opposite to the electric component; A cooling device for an electric component, characterized in that air blow ports are formed at least in side wall portions of a cylindrical body that surround the bimorph diaphragm and face each other in a plane direction of the bimorph diaphragm. 2. The apparatus according to claim 1, wherein the cylindrical body is a square cylinder having two pairs of side walls that are substantially parallel or perpendicular to the bimorph diaphragm, respectively. 3. The apparatus according to claim 1 or 2, wherein an air inlet is formed in a side wall portion of the cylindrical body facing the bimorph diaphragm surface. 4. The apparatus according to any one of claims 1 to 3, wherein there are a plurality of said bimorph diaphragms and they are housed in a cylinder substantially parallel to each other. 5. The tubular body forms a plurality of branch cylinders at an end opposite to the electric parts, and each of the branch cylinders accommodates a bimorph diaphragm extending substantially parallel to its axial direction. The device according to any one of claims 1 to 3 of claim for utility model registration. 6. A bimorph diaphragm is provided with respect to an imaginary plane orthogonal to the side wall passing through a side located on the side of the cooled electric component among openings provided in cylindrical side wall portions of the bimorph diaphragm facing each other in the plane direction. The device according to any one of claims 1 to 5, wherein the tip of the movable part is located on the opposite side of the electric cooling target part and is located within a range of 0 to 10 mm from the virtual surface.