JPS62108598A - Porous heat emission and reception element - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a porous heat radiation/reception body installed in various types of equipment.

Conventional technology In electrical and electronic equipment, audio equipment, and general machinery, radiators such as fin-shaped or coil-shaped radiators are arranged for components that require cooling, and heat receiving plates are arranged for heat sources so that they can transfer and receive heat. It is designed to radiate and receive heat.

However, these conventional heat dissipation and reception components do not have sufficient heat transfer efficiency, and must be relatively large in order to dissipate and receive the required amount of heat. This hinders the miniaturization and weight reduction of various types of equipment, and also makes it difficult to save labor.

Problems to be Solved by the Invention It is an object of the present invention to provide a small and lightweight left-standing heating element with high heat transfer efficiency.

Means for Solving the Problems The present invention is characterized in that it is made of a porous body in which a large number of pores are formed.

Function: When a porous heating element is arranged so as to be able to transfer heat to and receive heat from a heat source,
Performs heat exchange with the heat source. At this time, heat exchange is promoted in the left heating body because it has a large number of pores and a large surface area. Therefore, the required heat radiation and reception can be achieved even with a small and lightweight porous heating element.

Example Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a porous heat sink according to an embodiment of the present invention which is attached to a print head of a dot matrix printer.The heat sink 1 as a porous left heating body is a flat plate having a substantially rectangular shape in plan view. , one side is close to the solenoid for driving the print wire of the print head as a heat generation source, and the other side is fixed to the frame with a screw inserted through the mounting hole 2 with the other side exposed to the outside of the print head. This heat sink 1 is
Made of highly thermally conductive metals such as aluminum, aluminum alloys, and copper, or ceramics such as zirconia (Zi 02 ) and aluminum nitride (AJIN), many pores that communicate with each other are formed throughout the surface and interior of the material. Made of porous material. From the viewpoint of improving the heat dissipation characteristics of the heat dissipation plate 1, the pores preferably have a diameter of 5
It is formed to have a size of 0 to 1000 microns. Of course, the preferred size range of the pores varies depending on the usage environment of the heat sink 1, for example, whether it is used in a moving state or whether it is forced air cooled, but in general, if the pore diameter is less than 50 microns, the heat sink Air circulation within the pores on the surface of 1 and ventilation through the internal pores deteriorate, and if the diameter exceeds 1000 microns, the effect of increasing the surface area due to pore formation diminishes.
In either case, the heat exchange effect between the heat sink 1 and the heat source is reduced, and the heat dissipation performance of the heat sink 1 is deteriorated. Further, as the pore diameter increases, the mechanical strength of the heat sink 1 decreases, so there is an upper limit to the pore diameter from the viewpoint of strength, and the pore diameter is preferably 1000 microns or less.

The porous heat sink 1 is manufactured by a known method, for example, a porous crystal of a water-soluble salt having a particle size corresponding to the pores and having a uniform particle size is formed and then sintered. Molten aluminum having a lower melting point is poured into the material and solidified, and the salts are removed by washing with water to obtain a porous aluminum heat sink 1. Alternatively, a porous sintered heat sink 1 is obtained by mixing metal powder and salt powder with uniform particle size, sintering, and removing the salts.

The heat dissipation effect in a print head for a printer equipped with the heat dissipation plate 1 having the above-described configuration will be explained. As is conventionally known, the print head performs printing by driving the required print wire with a solenoid, and during this printing operation, the solenoid generates heat.
Constitutes a heat source.

Then, heat exchange is performed between the solenoid and one side surface of the heat sink 1 disposed close to the solenoid through the air. At this time, air circulates well through the pores formed in large numbers on the surface of the heat sink 10, promoting heat exchange.
Heat is transferred from the solenoid to the heat sink 1 to cool the solenoid. A portion of the heat transmitted to one side surface of the heat sink 1 is transferred to the heat sink 1.
Due to the thermal gradient between both sides, heat is transferred to the other side surface of the heat sink 1 through the constituent materials of the heat sink 1 itself, and the remaining portion through the air flowing through continuous pores inside the heat sink 1. Furthermore, the heat on the other side surface is quickly dissipated due to the same good heat exchange as described above between the other side surface and the atmosphere outside the print head. When the printer is operating, the print head moves back and forth, and the movement speed is particularly high when returning to the printing start position, so heat exchange on the outer surface of the heat sink 1 is promoted and the thermal gradient inside the heat sink 1 is large. In addition, heat transfer by air circulation through the pores inside the heat sink 1 is also effectively achieved.

Note that if forced air cooling is performed by blowing air toward the heat sink 1 from a cooling fan (not shown), the heat dissipation performance will be improved.

The heat dissipation effect of the heat dissipation plate 1 having the above-described configuration and operation was confirmed as follows through a comparative experiment. That is, 10 watts of heat was continuously generated from the solenoid of the print head to raise the temperature of the central portion of the solenoid to 100° C., and the heat was dissipated to the external atmosphere at 30° C. via various heat radiators. In order to achieve the required heat dissipation under the above experimental conditions, conventional aluminum fins require a fin external dimension of 50 mm x 6
The number of fins required for 4 mm x 4 mm thickness is 10.
15 pieces when 40mm x 45mm x 4mm thick,
And when the thickness was 36 mm x 50 mn + x 4 nv, the number of sheets was 15. On the other hand, according to the present invention, the heat sink 1 has a pore diameter of 500 μm.
In the case of a porous plate made of pure aluminum with a porosity of 60%, one piece measuring 40 mm x 40 mm x 5 mm thick was sufficient.

2 and 3 show a heat sink 11 for a print head according to a second embodiment of the present invention, which heat sink 11 is adapted for use in a poorly ventilated environment. That is,
On one side of the heat dissipation plate 11, for example, on the outer surface of the print head, there are a plurality of grooves 1 having a V-shaped cross section extending parallel to each other over the entire width thereof.
3 is formed to increase the surface area of the heat sink 11 and improve air permeability. Note that the grooves 13 may be formed on both sides of the heat sink 11. Moreover, 12 in the figure is a mounting hole.

The operation of the second embodiment is substantially the same as that of the first embodiment, so a description thereof will be omitted (the same applies hereinafter).

FIG. 4 shows a heat sink 21 according to a modification of the second embodiment.
, the groove 23 of the heat sink 21 extends obliquely to the printing direction, that is, with respect to the moving direction A of the heat sink 21, and the groove 23 of the heat sink 21
1 increases the effective contact area of the V-groove inclined surface with respect to the air flow, roughly promotes heat exchange between the heat sink 21 and the outside air, and improves the air permeability of the heat sink 21. .

22 indicates a mounting hole.

5 and 6 show a heat dissipation plate 31 according to a third embodiment of the present invention, in addition to the fact that this heat dissipation plate 31 is formed in a circular shape in plan view compared to those of the above-mentioned embodiments, appropriate parts such as V
The difference is that a stud 34 is installed in a groove 33. The stud 34 disturbs the air flow caused by the movement of the heat sink 31 or the air blown from the cooling fan, and generates a vortex (Karman vortex) in the vicinity thereof, thereby promoting air circulation around the heat sink 31 and improving the heat radiation effect. let Note that 32 is a mounting hole.

FIG. 7 shows a heat sink 41 according to a fourth embodiment of the present invention, in which a non-porous body 43 is integrated into a porous body 42 having the same structure as the heat sink 1 shown in FIG. or a porous body 42 and a non-porous body 43 are combined to prevent noise from flowing out through the heat sink plate 41.

In order to integrally form the non-porous body 43, the metal porous body 42
thermally or chemically etched or impregnated with a low melting point solder on one side. On the other hand, in order to combine the non-porous body 43, the plate-shaped non-porous body 43 made of a metal plate, preferably a control alloy such as an aluminum-zinc alloy, is combined with the porous body 4.
This heat dissipation plate 41, which is welded or bonded to the heat source 2, is attached to various devices such as printer print heads with the non-porous body 43 facing the heat source, and when the printer is in operation, it has the same heat dissipation effect as that of the above embodiment, and also has the following effects. It works like a mute function. That is, when noise and pulsation occur as a result of printer operation, sound waves such as noise heading toward the heat sink 41 first collide with the nonporous body 43 of the heat sink 41, and the low frequency portion of the sound waves travels toward the heat sink 41. The quality is reduced by the most effective. The high-frequency part that has passed through the non-porous body 43 is made to have a lower frequency when passing through, and is absorbed by the porous body 42 together with the rest of the low-frequency part that has passed through the non-porous body 43, or due to the muffler effect of the porous body 42. The noise is reduced by As a result, compared to a heat sink made of a porous corpus luteum body, for example, the heat sink 1 of FIG. 1, the sound pressure flowing outside through the heat sink 41 during equipment operation is significantly suppressed.

FIG. 8 shows an example of use in which the heat sink according to each of the embodiments described above is combined with a heat vibrator. The micro-heat vibrator 4 is used to directly thermally connect the space between the two to radiate heat directly to the outside air, thereby increasing the heat radiation effect and dissipating heat to various parts (not shown) placed between the heat generating part 3 and the heat sink 1. Removes negative influences. In addition,
In the figure, 5 indicates a pressure body of a device to which the heat sink 1 is attached.

Also, if the distance between the heat generating part 3 and the heat sink 1 is relatively short,
Aluminum instead of Heat Vibe 4.

A bar or plate made of a good thermal conductor such as copper may also be used.

FIG. 9 shows a thermal circuit using a porous heat radiation/reception body according to a fifth embodiment of the present invention. In the figure, 50 is a fluid circuit in which a fluid as a heat exchange medium of general machinery or a heat exchanger circulates, and a heat receiving body 51 and a heat radiating body 52 (not shown) are provided on the heat absorption side and the heat radiation side of the circuit. They are arranged so that they can receive and receive heat from the heat source. Heat receiving body 51 and heat radiating body 52
are made of a thin-walled hollow cylindrical porous body with the same configuration, and the first
It is manufactured in the same manner as the heat sink 1 shown in the figure.

The operation of this embodiment is such that the heat receiving body 51 receives heat on its outer circumferential surface through a heat exchange action with a heat generating source, while its inner circumferential surface receives heat between the heat receiving body 51 and the heat absorbing side of the fluid circuit 50 passing through the hollow portion of the heat receiving body 51. to perform heat exchange. Since the heat receiving body is a porous body, this heat exchange is performed efficiently for the reason described regarding the heat sink 1. The received heat is propagated to the heat radiation side by the fluid circulating in the fluid circuit 50, and the same high efficiency as described above is achieved between the heat radiation side of the fluid circuit 5o and the heat radiator 52 surrounding it, and then between the heat radiator 52 and the heat absorption source. Heat is absorbed by the heat absorption source due to the heat exchange action of After all, since the heat exchange efficiency is good, the energy loss of the entire system can be reduced and labor savings can be achieved.

FIG. 10 shows a porous heat receiving body 61 according to a sixth embodiment of the present invention, and the heat receiving body 61 is manufactured in a hollow cylindrical shape with a bottom in substantially the same manner as the heat sink 1 of FIG. 1, and is preferably made of aluminum. , aluminum alloy, ceramic, or other non-magnetic material. When a fluid containing heat is introduced into the heat receiving body 61, the heat receiving body 61 receives heat from the fluid and releases the heat to the outside. When a magnetic fluid is used as the fluid, if the magnet 62 is placed outside the heat receiving body 61, the magnetic fluid is attracted to the inner peripheral surface of the heat receiving body 61 by magnetic force, improving heat receiving efficiency.

FIG. 11 shows a porous heat receiving body 71 according to a seventh embodiment of the present invention, and the heat receiving body 71 has a round bar shape. When the lower half of the heat receiving body 71 is immersed in the high temperature fluid contained in the container 72, the heat received from the fluid is radiated to the outside from the upper half.

12 and 13 show a porous heating body according to an eighth embodiment of the present invention applied to a ventilation duct section of an air conditioner, and the duct section has a heat receiving body 81 and a heat radiating body as main elements. 82, both of which are manufactured in substantially the same manner as the heat sink 1 described above. The heat sink 82 has three components 82a, 82a,
82a, and has a hollow cylindrical shape as a whole, and is enclosed in a thin annular outer wall member 83. In the internal space of the heat sink 82, there is a heat receiver 81 in the shape of a truncated cone tapered in the direction of air blowing.
are tightly fitted through a thin annular partition member 84 made of aluminum, for example. The partition wall 85 is interposed between the adjacent constituent parts 82a, 82a of the heat sink 82, and its outer and inner edges are coupled to the outer wall member 83 and the partition member 84, and functions as a reinforcing member.

A fan 86 is disposed in a space defined by one end surface of the heat receiving body 81 and the partition member 84.

Next, the operation of the air conditioner duct section having the above configuration will be explained. First, when the fan 86 is rotated by a drive source (not shown), clean air is supplied in the direction of arrow B through the heat receiving body 81 made of a porous body. At this time, the heat receiving body 81
A tapered partition wall member 84 surrounding the duct prevents air from leaking to the outside and converges the air flow in the axial direction of the duct.

When fresh air is supplied in this way, air that is still warm but contaminated during heating, for example, is discharged through the porous body 82 in the direction of arrow C.

When this air is discharged, the discharged air is retained through the heat radiator 82 which has an excellent heat exchange effect and the heat receiver 81 which is arranged adjacent to the heat radiator 82 and which has a similar heat exchange effect, like the heat radiator 1 described above. The waste heat is efficiently transferred to the supplied air, making effective use of waste heat.

Note that the above-mentioned ventilation system can of course be applied to various types of equipment other than air conditioners.

Effects of the Invention As described above, according to the present invention, the left heating body arranged to be able to transfer heat to and from the heat source is made of a porous material, so its heat exchange characteristics, that is, heat transfer properties are good, and heat dissipation is improved. This makes it possible to reduce the size and weight of the left heating element forming the heat receiving part and/or the heat receiving part, as well as various equipment equipped with this, and to save labor in the equipment.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a porous heat sink according to a first embodiment of the present invention, FIGS. 2 and 3 are a plan view and a cross-sectional view of a heat sink according to a second embodiment of the present invention, and FIG. 4 is a plan view of a heat sink according to a modified example of the same embodiment, FIG. 5 is a plan view according to a third embodiment of the present invention, FIG. 6 is a sectional view taken along the line Vl-Vl in FIG. 7 is a schematic cross-sectional view showing a heat sink according to a fourth embodiment of the present invention, FIG. 8 is a partially cross-sectional partial schematic plan view showing a case where the heat sink of the present invention is used in combination with a heat pipe, FIG. 9 is a schematic configuration diagram showing a thermal circuit equipped with a standing heating element according to the fifth embodiment of the present invention, and FIG.
FIG. 11 is a perspective view of the heat receiving body according to the seventh embodiment of the present invention, and FIG. 12 is a perspective view of the heat receiving body according to the seventh embodiment of the present invention used in a ventilation system. FIG. 13 is an end view showing the heating body, and a sectional view taken along the xm-xm line in FIG. 12. 1.11.21, 31.41... Heat sink, 3... Heat generating part, 4... Heat pipe, 13.33... Groove, 3
4... Stud, 42... Porous body, 43... Non-porous body, 51.61.71.81... Heat receiving body, 52.
82... Heat sink. Figure 9 Figure 11 Figure 12 Figure 13 Vessel

Claims (5)

[Claims] (1) A porous heat radiation/reception body characterized by being made of a porous body in which a large number of pores are formed. (2) The porous heat dissipating body according to claim 1, wherein the pores have a diameter of 50 microns to 1000 microns. (3) A porous heat radiation/reception body according to claim 1 or 2, wherein a groove is formed on at least one side surface. (4) A porous heat dissipating and receiving body according to claim 1, 2, or 3, wherein a nonporous body is provided on one side surface. (5) The porous heat radiation/reception body according to claim 1 or 2, which is formed into a hollow cylindrical shape and is capable of heat exchange through the inner and outer circumferential surfaces.