JPH05251595A - Variable heat resistance device - Google Patents

Abstract

PURPOSE:To provide mechanical strength as a structure material and to enable electrical control of thermal conductivity from an outside. CONSTITUTION:A thermal bad conductor 4 having mechanical strength as a structure material is interposed between first and second thermal good conductors 2, 3 having mechanical strength as a structure material. They are combined each other and a third thermal good conductor 5 is thermally combined to the first thermal good conductor 2 to bring third and fourth thermal good conductors 5, 6 into contact with each other. A piezoelectric element 8 is interposed between a contact part 7 and a fixing holding member in a direction to pressurize the contact part 7. An application voltage control means 9 which controls a voltage to be applied to the piezoelectric element 8 is connected to the piezoelectric element 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable thermal resistance device that can be used to control the temperature of electronic devices, mechanical devices and the like.

In order to operate an electronic device or the like normally,
It is necessary to maintain the temperature within a certain range, so in order to efficiently dissipate the heat generated by electronic components, various heat dissipating means such as heat dissipating fins and heat pipes should be used to keep the electronic device in an appropriate temperature range. I'm trying to control within.

[0003]

2. Description of the Related Art In particular, various sensors such as an electronic device mounted on an artificial satellite or a radiometer must be thermally controlled within an appropriate temperature range in order to operate them normally.
Therefore, generally, radiation cooling, a thermal louver, a heat pipe, a multi-layer heat insulating material and the like are combined to control the temperature of an electronic device mounted on an artificial satellite.

[0004]

Among the above-mentioned cooling means, the radiative cooling is for cooling by radiating energy to outer space, which is widely used in artificial satellites, but its cooling capacity is fixed. Thermal louvers
The cooling capacity can be changed by changing the blade angle, but there is a problem that it is structurally complicated and expensive.

Further, the heat pipe is used because of its extremely high thermal conductivity, but it is difficult to electrically control the thermal conductivity. The purpose of the multilayer heat insulating material is to block radiant energy, and the radiant energy can be controlled by the type, the number of layers, and the method of implementation, but the thermal resistance cannot be varied by external means.

The present invention has been made in view of the above points, and an object of the present invention is to provide a variable heat generator which has mechanical strength as a structural material and whose heat conductivity can be electrically controlled from the outside. It is to provide a resistance device.

[0007]

FIG. 1 shows the principle of the present invention. First and second having mechanical strength as a structural material
A heat insulating material having a mechanical strength as a structural material or a poor heat conductor 4 is also interposed between the good thermal conductors 2 and 3 to mechanically couple them.

The third good thermal conductor 5 is connected to the first good thermal conductor 2, the fourth good thermal conductor 6 is connected to the second good thermal conductor 3, and the third and fourth good thermal conductors 5, 6 are brought into contact with each other.
The piezoelectric element 8 is interposed between the contact portion 7 and the fixed holding member in a direction of pressing the contact portion 7, and the applied voltage control means 9 for controlling the voltage applied to the piezoelectric element 8 is provided in the piezoelectric element. It is provided by connecting to 8.

[0009]

Since the poor heat conductor 4 is interposed between the first good heat conductor 2 and the second good heat conductor 3, the second good heat conductor 2 passes from the first good heat conductor 2 through the poor heat conductor 4. Little heat flow to 3.

The heat flow is arranged on the low temperature side from the first good thermal conductor 2 arranged on the high temperature side through the route of the third good thermal conductor 5, the contact thermal resistance 7 and the fourth good thermal conductor 6 as shown by an arrow A. Flow into the separated second good thermal conductor 3. The value of the contact thermal resistance 7 in the middle of the heat flow can be adjusted by controlling the contact pressure between the third and fourth good thermal conductors 5 and 6 by controlling the voltage applied to the piezoelectric element 8 by the applied voltage control means 9. Is.

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 2 shows a sectional view of the embodiment of the present invention.
A first cylinder 12 formed of a metal such as aluminum, stainless steel, or copper and a heat insulating cylinder 16 formed of, for example, CFRP are fixed to each other by screws 18 with abutting annular flanges 12a and 16a. Insulation cylinder 16
Further, the annular flanges 16b and 14a are brought into contact with the second cylinder 14 formed of the same metal material as that of the first cylinder 12 and fixed by the screw 20.

The thermal conductivity of the high-strength CFRP of the unidirectional reinforcing rod differs depending on the fiber direction, but it is 10 (W / m
C) and about 1/20 of aluminum. Therefore, from the first cylinder 12 arranged on the high temperature side to the heat insulating cylinder 16
Almost no heat flow to the second cylinder 14 via the.

The first cylinder 12 is connected to the heat generating side of the electronic device, for example, and the second cylinder 14 is connected to the heat radiating side such as radiative cooling. Since both the first cylinder 12 and the second cylinder 14 are made of metal, they have mechanical strength and rigidity as a structural material. Further, since the heat insulating cylinder 16 is also made of CFRP, it has mechanical strength and rigidity as a structural material.

A first bypass member 22 made of a metal such as aluminum or copper is fixed to the first cylinder 12 by a screw 24, and the first bypass member 22 is made of a flexible metal such as aluminum. Second bypass member 2
6 is fixed by a screw 28.

On the other hand, a flexible fourth bypass member 30 made of a metal such as aluminum is fixed to the second cylinder 14 with a screw 32, and the flexible fourth bypass member 3 is provided.
A third bypass member 34 formed of a metal such as aluminum or copper is fixed to 0 by a screw 36, and a free end of the third bypass member 34 is in contact with the flexible second bypass member 26.

Cylindrical frames 40 and 42 are fixed to the flange 38 protruding inward from the heat insulating cylinder 16 with screws 44, and the cylindrical frames 40 and 42 are fixed to the screws 44 and 42.
They are connected to each other by 46.

The third bypass member 34 is a cylindrical frame 4
2 is inserted into the cylindrical frame 42 through the hole 43 formed in the one end 42a, and the heat insulating material 48 is interposed between the annular protrusion 34a of the third bypass member 34 and the one end 42a of the cylindrical frame 42. It is equipped.

The free second end of the flexible second bypass member 26 is inserted into the cylindrical frame 42 through the hole 45 of the cylindrical frame 42, and one end 40a of the cylindrical frame 40 is formed.
The piezoelectric element 50 and the heat insulating material 52 are interposed between the flexible second bypass member 26 and the flexible second bypass member 26.

As the piezoelectric element 50, Pb (Zr, T
i) A laminated piezoelectric ceramic such as O ₃ (PZT) or PbTiO ₃ (PT) can be used. The above-mentioned heat insulating material 52 is adhered to one end of the piezoelectric element 50, and heat is applied to the piezoelectric element 50.
To prevent it from flowing into.

The piezoelectric element 50 is connected to a DC voltage power supply 54, and the DC voltage power supply 54 can arbitrarily adjust the applied voltage within the range of 0 to 150V. When a voltage is applied to the piezoelectric element 50, distortion occurs in the direction of arrow B, but since the cylindrical frames 40 and 42 are fixed so as not to cause displacement, the flexible second bypass member 26 and the third bypass member 34 are fixed. A pressure that is almost proportional to the voltage is generated on the contact surface (see FIG. 3).

Since there is a fixed relationship between the contact pressure and the contact thermal resistance if the material and surface roughness are specified, the piezoelectric element 5
By controlling the contact pressure at 0, the thermal resistance between the flexible second bypass member 26 and the third bypass member 34 can be controlled.

The heat from the first cylinder 12 arranged on the high temperature side is applied to the first bypass member 22 and the flexible second bypass member 2.
6, third bypass member 34, flexible fourth bypass member 3
It is transmitted to the second cylinder 14 through the path of 0.

As described above, by controlling the voltage applied to the piezoelectric element 50, the flexible second bypass member 2 is controlled.
Since the contact pressure between 6 and the third bypass member 34 can be controlled, the contact thermal resistance can be controlled. This makes it possible to electrically control the heat flow through the bypass path from the outside by remote control or the like.

[0024]

Since the variable thermal resistance device of the present invention is configured as described above in detail, it has the following effects.

(A) In the heat control system, the heat resistance of the heat conduction path can be made variable. (B) Power consumption is extremely low compared with the heater control that is normally performed.

(C) The thermal resistance can be controlled by remote control. (D) A variable thermal resistance device that can be used as a structural material can be provided.

[Brief description of drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a sectional view of an embodiment of the present invention.

FIG. 3 is a graph showing the relationship between the applied voltage and the generated force when the device is fixed so that displacement does not occur.

[Explanation of symbols]

 2 1st thermal good conductor 3 2nd thermal good conductor 4 Heat bad conductor 5 3rd thermal good conductor 6 4th thermal good conductor 7 Contact thermal resistance 8 Piezoelectric element 9 Applied voltage control means 12 1st cylinder 14 2nd cylinder 16 Adiabatic cylinder 22 2nd 1 Bypass member 26 Flexible 2nd bypass member 30 Flexible 4th bypass member 34 3rd bypass member 50 Piezoelectric element 54 DC power supply

Claims (2)

[Claims] 1. A first material having mechanical strength as a structural material.
And a heat-defective conductor (4) having mechanical strength as a structural material, which is also interposed between the second heat-good conductors (2, 3), and these are coupled to each other, and the first heat-good conductor (2) Is thermally coupled to the third good thermal conductor (5), and the second good thermal conductor (3) is thermally coupled to the fourth good thermal conductor (6) to provide the third and fourth good thermal conductors (5, 5). 6) are brought into contact with each other, and a piezoelectric element (8) is interposed between the contact portion (7) and the fixed holding member in a direction of pressurizing the contact portion (7), and applied to the piezoelectric element (8). A variable thermal resistance device, characterized in that an applied voltage control means (9) for controlling the applied voltage is connected to the piezoelectric element (8). 2. The third good heat conductor (5) is a flexible good heat conductor.
Is in contact with the fourth good thermal conductor (6) via (26), and a heat insulating material (52) is interposed between the flexible good thermal conductor (26) and the piezoelectric element (8, 50). The variable thermal resistance device according to claim 1, wherein the variable thermal resistance device is provided.