JPH03116961A - Heat dissipating device - Google Patents

Abstract

PURPOSE:To enable a heat dissipating device to dissipate heat efficiently without any vibration and noise by a method wherein air is made to flow out through an opening by vibrating a vibrating plate to be fed to a heat dissipating device apart from a case provided with the vibrating plate by a certain distance, and the vibration frequency of the vibration plate is set low enough to be out of an audible frequency band. CONSTITUTION:A case 17 is provided with a vibrating plate 10, drive systems 13 and 14 which drive the vibrating plate 10, and openings 15 and 16 provided to, at least, a part of the case 17. A radiator 6, which is thermally coupled with a heat releasing component 5 and arranged apart from the openings 15 and 16 by a prescribed distance confronting them, is provided. Air is exhausted from the case 17 by the vibration of the vibrating plate 10 through the openings 15 and 16 to be fed to the radiator 6 apart from the case 17 by a prescribed distance. The vibrator 10 is driven at a frequency out of an audible frequency band. By this setup, a heat dissipating device of this design can efficiently dissipate heat without generating any vibration and noise.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a heat dissipation device suitable for use in a device such as a power amplifier incorporating a heat generating component such as a power transistor.

[Conventional technology]

A power amplifier has a built-in power transistor for driving a speaker or the like. Power transistors generate heat because a large current is passed through them.

In order to discharge this heat to the outside of the device, a heat radiator such as a heat sink or heat pipe, or a fan is used.

[Problem to be solved by the invention]

However, since heat sinks, heat pipes, etc. utilize natural convection of heat, they are not only difficult to dissipate efficiently, but also require space above and below these heat radiators, and it is difficult to seal the device. It has the disadvantage that it cannot be planned.

In addition, heat dissipation devices using fans use forced air cooling, which improves heat dissipation efficiency, but the motor that drives the fan generates vibrations, noise, etc., and when used in audio equipment such as power amplifiers, the product value is reduced. There was a drawback that the amount was reduced.

The present invention has been made in view of this situation, and is intended to enable efficient heat dissipation without generating vibrations or noise.

[Means to solve the problem]

The heat dissipation device of the present invention includes: a diaphragm that vibrates at a predetermined frequency; a drive system that drives the diaphragm; a container that includes the diaphragm and the drive system and has at least one opening; and a heat radiator to which a heat generating component is thermally coupled, the heat radiator being arranged at a predetermined distance from the opening.

[Effect]

In the heat radiator having the above configuration, air is released from the opening of the container by the vibration of the diaphragm, and is supplied to the radiator spaced a predetermined distance apart. The diaphragm is driven, for example, at a frequency outside the audio frequency band.

Therefore, heat can be efficiently radiated without generating vibrations, noise, etc.

〔Example〕

FIG. 1 shows a state in which an embodiment of the heat dissipation device of the present invention is attached to a power amplifier as an electronic device.

As shown in the figure, the heat radiating device of the present invention basically includes an air blower 1 and a radiator 2.

The heat sink 2 is an exhaust port 4 provided at the rear of the power amplifier 3.
The heat radiation ports 6 are arranged to face each other.

Further, the blower 1 is arranged at a predetermined distance d from the radiator 2 so that the openings 15 and 16 thereof face the radiator 2.

FIG. 2 is an enlarged perspective view of the blower 1 and the radiator 2. FIG. As shown in the figure, a power transistor 5 as a heat generating component attached to a substrate 7 is fixed to the side surface of the heat sink 2, and the power transistor 5 and the heat sink 2 are thermally coupled.

Figures 3 and 4 are a cross-sectional view (cross-sectional view taken along the line III-III in Figure 2) and a longitudinal cross-sectional view (cross-sectional view taken along the line IV-IV in Figure 2) of the blower 1 and the radiator 2, respectively. be.

In these figures 17 is a closed container with an opening 15,16. A diaphragm holding member 12 holds the substantially circular flat diaphragm 10 via the damper 11. Reference numeral 13 denotes a magnet, which is fixed to approximately the center of the diaphragm 10.

14 is a coil fixed at a position facing the magnet 13 of the container 17. 18 and 19 are spaces facing one side and the other side of the diaphragm 10, and have openings 15 and 1, respectively.
It is connected to 6.

The damper 11 connects the entire outer periphery of the diaphragm 10 to the holding member 12, and prevents air from flowing in and out between the spaces 18 and 19.

Next, its operation will be explained.

The coil 14 is connected to a frequency outside the audible frequency band (for example, 20H).
If you supply a signal with a frequency below z).

The magnet 13 is attracted or repelled by the coil 14. As a result, the magnet 13, and therefore the diaphragm 10, vibrate in a substantially perpendicular direction (vertical direction in FIG. 3) at the same frequency as the supplied signal.

As shown in FIG. 5, when the diaphragm 10 moves upward in the figure, the volume of the space 19 decreases and the volume of the space 18 increases. The space 19 is arranged in a direction perpendicular to the vibration direction of the diaphragm 10 (
It is arranged linearly in the horizontal direction (in the figure), one end is closed, and an opening 16 is formed in the other end. Therefore, the air compressed by the reduction in the volume of the space 19 is guided into the space 19 and flows out linearly to the left in the figure. Since the heat sink 6 of the heat sink 2 is arranged parallel to this outflow direction, air passes through the heat sink 6 and reaches the power amplifier 3.
is discharged to the outside from the exhaust port 4.

Since the opening 16 of the container 17 and the radiator 2 are separated by a distance d, some of the air is also discharged to the side (upward in FIG. 5 or in a direction perpendicular to the page), but as described above, ,
Since the space 19 guides the air linearly, the amount discharged laterally is smaller than the amount discharged linearly.

On the other hand, due to the increase in the volume of the space 18, the air pressure therein decreases, and air flows into the space from the side of the opening 15 (downward in FIG. 5 or in a direction perpendicular to the plane of the paper). At this time, the heat radiation port 6 also connects the space 1 through the opening 15.
Air flows linearly into the space 8, but air flows in the opposite direction from the opening 16 into the heat radiation port 6, so the amount of linear air flowing into the space 18 is equal to the amount of air flowing from the side. There are fewer than.

Therefore, when the diaphragm 10 moves in the opposite direction (downward in the figure), the volume of the volume 18 is reduced, and the cold air that had been flowing into it is discharged to the heat radiation port 6. At this time, the volume of the space 19 increases, and cold air flows into it.

Such an operation is repeated, and the cooled air passes through the heat radiating port 6 of the radiator 2, and the heat of the radiator 2, that is, the heat of the power transistor 5, is discharged to the outside.

Since the frequency of the diaphragm 1O is low outside the audible band, the vibrations are small and are not heard as noise by humans.

6 to 8 show the configuration of an embodiment of a drive system for driving the diaphragm.

In the embodiment shown in FIG. 6, the coil 14 has an air core, and a hole 21 is formed in the center thereof.

In the embodiment shown in FIG. 7, an iron core 2 is placed in the center of the coil 14.
Further, the diaphragm 10 is made of a magnetic material, and the magnet 13 is not provided.

In the embodiment shown in FIG. 8, the coil 14 is a voice coil and is attached to the diaphragm 10. This coil 14 is placed in the magnetic gap formed by the magnet 23 and the yoke 24.

In any of these embodiments, the diaphragm 10 can be vibrated by supplying a signal of a predetermined frequency to the coil 14, as in the case described above.

FIG. 9 shows the configuration of an embodiment in which two diaphragms are used.

In this embodiment, one diaphragm 10A is connected to the holding member 12A via the damper 11A, and the other diaphragm 10B is connected to the holding member 12A via the damper 11A.
are each held by a holding member 12B via a damper 11B. There is a space 18A on the outside and inside of the diaphragm 10A.
and 19A, and there is a space 18B on the outside and inside of the diaphragm 10B.
and 19B are formed, respectively.

A partition plate 31 is arranged between the inner spaces 19A and 19B to prevent air from flowing in and out between them.

Further, one coil 14 is arranged on this partition plate 31,
The diaphragm 10A and I
Magnets 13A and 13B are arranged on the inner surface of the OB, respectively.

Openings 15A and 16 communicate with spaces 18A and 19A.
Openings 15B and 16B are each formed on one surface (the left side in the figure) of the container 17 so that the opening A communicates with the spaces 18B and 19B.

Further, the openings 16A and 16B are formed adjacent to each other, whereas the openings 15A and 15B are formed adjacent to each other.
is located apart from.

In this embodiment, by arranging the N pole (or S pole) of the magnet 13A and the S pole (or N pole) of the magnet 138 so as to face the coil 14, the diaphragm 10A is placed inside (
When the diaphragm 10B is moved inward (or outward), the diaphragm 10B can also be moved inward (or outward). In this way,
Compared to the case where air flows out (or flows in) from both adjacent openings 16A and 16B at the same time, and when air flows out from opening 16A (or 16B), air flows in reversely through opening 16B (or 16A). The heat radiating section 2 can be effectively cooled.

In the embodiment shown in FIG. 9, the diameter of the diaphragm is 70II.
Iffl, vibration amplitude 4rmm, vibration frequency 15Hz
Or 19Hz, and as shown in FIG.
We were able to obtain the results shown in the figure.

In FIG. 11, one curve A represents the case where the frequency is 19 Hz, and one curve B represents the case where the frequency is 15 Hz.

From these curves, the distance d between blower 1 and radiator 2 is 30
It can be seen that the maximum wind speed (approximately 1.1 m/s at 19H2, approximately 0.9 m/s at 15 Hz) is obtained from m garden to 35 m garden.

The blower of the embodiment shown in Fig. 9 is approximately 30+m from the radiator.
When the temperature of each part was measured by placing them separately in a power amplifier, the results shown in FIG. 12 were obtained.

In Fig. 12, curves A and B are the power transistor fixed to the heatsink 2, curve C is the heatsink on the power supply board, curves are the openings 16A and 16B of the blower 1, curve E is the power transformer, and curve F is the power transistor fixed to the heatsink 2. is the board on the radiator, curve G is the outlet board, and curve H is the air 1 curve I (J
) represents the temperature of the rear panel and metal cover, the curved line represents the temperature of the front panel, and the curved line represents the temperature of the room where the power amplifier is installed.

On the other hand, FIG. 13 shows the temperature at each part of the same power amplifier when only the radiator 2 is provided without the blower 1. The symbols in FIG. 13 correspond to the symbols in FIG. 12.

As is clear from comparing Figures 12 and 13.

The temperature of the power transistor (curves A and B) is higher in the case shown in Fig. 12, but the temperature inside the power amplifier (
It can be seen that the temperatures of the curves C to K) are lower in FIG. 12 than in FIG. 13.

In particular, the temperature (curve J) of the metal cover (top surface of the power amplifier housing) is significantly lower in FIG. 12.

FIG. 14 shows yet another embodiment.

In this embodiment, the blower 1 and the radiator 2 are combined, but since openings 41 are formed on the side surface and top surface near the joint, they operate in the same way as if they were separated.

〔Effect of the invention〕

As described above, according to the heat radiating device of the present invention, the diaphragm is vibrated to cause air to flow out from the opening, and the air is supplied to the radiator spaced a predetermined distance apart, which is more efficient than when using natural convection. can dissipate heat.

Furthermore, by setting the vibration frequency of the diaphragm to a low frequency outside the audible band, vibrations and noise can be reduced.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the structure of an embodiment of the heat dissipation device of the present invention installed in a power amplifier, FIG. 2 is a perspective view showing the structure of an embodiment of the heat dissipation device of the present invention, and FIG. is a sectional view taken along the line III-III in Fig. 2, and Fig. 4 is a sectional view taken along the line IV-I in Fig. 2.
FIG. 5 is a cross-sectional view taken along the line V, and FIG. 5 is a cross-sectional view illustrating the air blowing operation of an embodiment of the heat dissipation device of the present invention. 6 to 8 are cross-sectional views of an embodiment of a drive system for driving the diaphragm of the heat dissipation device of the present invention, and FIG. 9 is an embodiment of the air blower of the present invention when two diaphragms are used. A cross-sectional view of
FIG. 10 is an explanatory diagram showing the configuration of wind speed measurement using an embodiment of the heat dissipation device of the present invention, FIG. 11 is a characteristic diagram showing the wind speed measurement results using the configuration of FIG. 10, and FIG. 12 is the heat dissipation device of the present invention. Figure 13 is a characteristic diagram showing the temperature measurement results of each part when one embodiment is used in a power amplifier. FIG. 14 is a perspective view showing the configuration of still another embodiment of the heat dissipation device of the present invention. 1...Blower, 2...Radiator, 3...Power amplifier, 4...Exhaust port, 5...Power transistor, 6
... Heat radiation port, 7 ... Board, 11 ... Damper, 1
2, 12A, 12B...holding member, 13.13A
, 13B, 23...Magnet, 14...Coil, 15.15A, 15B, l 6.16A, 16B・
...Opening, 17...Container, 18.18A, 18B,
19.19A, 19B... Space, 21... Air core, 2
2... Iron core, 24... Yoke, 31... Partition plate. Fig. 3 Fig. 5 Fig. 9 Section 1O Fig. d: N branch de color gain and at, + Tabarata [ (mm) Fig. 11

Claims (1)

[Scope of Claims] A diaphragm that vibrates at a predetermined frequency; a drive system that drives the diaphragm; a container that includes the diaphragm and the drive system and has at least one opening; and a container that faces the opening. and a heat radiator to which a heat generating component is thermally coupled, the heat radiator being arranged at a predetermined distance from the opening.