JPS5935783Y2 - heat flow sensor - Google Patents

Description

[Detailed description of the invention] This invention is a heat flow sensor that measures the heat flow density from the temperature difference between the front and back surfaces of a heat resistance plate. A differential thermocouple is formed by bringing a material plate into electrical contact with the front and back surfaces of the thermal resistance plate, and the temperature difference on the thermal resistance plate is immediately extracted as the output voltage of the differential thermocouple to measure the heat flow density. The present invention relates to a heat flow sensor using a heat flow sensor.

This type of heat flow sensor has advantages such as a simple structure because the differential thermocouple itself forms the heat flow sensor, and excellent mechanical strength because the thermocouple material is usually a gold-enhanced material.

However, since the thermal resistance plate is a thermocouple material, it has good thermal conductivity and therefore the temperature drop across the plate is extremely small, requiring the use of extremely sensitive instruments to detect its output voltage. There is a practical inconvenience in that it can only be used for the purpose of measuring extremely high heat flow densities such as 1,000,000 kcaV77It or more.

Furthermore, since the thermocouple material is conductive, it is usually necessary to cover the outside with an electrical insulating material during use, but ordinary insulating paint can only withstand relatively low temperatures1, and it may cause uneven coating etc. There are disadvantages such as non-uniformity of thickness, and it is desirable to improve the electrical insulation.

In view of these circumstances, the present invention aims to provide a heat flow sensor that eliminates the above-mentioned disadvantages and further improves practicality.The present invention provides a heat flow sensor that eliminates the above-mentioned disadvantages and further improves practicality. Furthermore, electrical insulation is provided using a metal oxide film.

The present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a state in which heat flow density is measured by a thin heat flow sensor in which the thermocouple material also serves as a heat resistance plate.

In this figure, thermocouple material plate A is made of, for example, a consquuntan plate, and thermocouple material plates B and B' are closely attached to the front and back surfaces of the thermocouple material plate in electrical contact.

B and B' are plates made of the same material, such as a copper plate.

In this way, a copper-constantan-copper differential thermoelectric body is formed, and a temperature drop occurs on plate A according to the heat flow density dissipating from the high-temperature wall surface in the direction of the arrow, and the temperature difference is immediately outputted by the differential thermocouple. It can be obtained as a voltage, which can be measured using a voltmeter 1
I can give instructions and things.

In this case, the lead wires 2, 2 are made of the same material as the thermocouple material plates B, B', and in this example are copper.

In the heat flow sensor described above, since the thermal resistance plate A is a metal plate, the thermal conductivity of the plate A is extremely high, and the temperature drop is usually extremely small.

Therefore, in this heat flow sensor, the voltage applied to the voltmeter 1 is extremely small, and if a highly sensitive voltmeter is used for all culms, or if a general voltmeter is used, the heat flow density dissipated from the wall is extremely high. It is only of practical use in certain cases.

Here, in the present invention, as shown in Fig. 2 a - c, a perforated type thermocouple is made of the same material as the thermocouple material plate A, and has one through hole 3, 3... on the ground. Material plate A
A heat flow sensor is constructed by separately preparing a thermocouple material plate B and a thermocouple material plate A with a thermocouple material plate A interposed therebetween.

According to this heat flow sensor, the apparent thermal conductivity of the thermocouple material plate A is deteriorated by the presence of the holes 3, 3, etc., and therefore the temperature drop across the entire heat resistance plate is increased. It is possible to obtain a state of electrical contact at the same time as to obtain a large differential thermocouple output.

The heat flow sensor shown in FIG. 2a has a plate A interposed in the center between the plates A.

The manufacturing method for this heat flow sensor is to apply the latest thermo-compression welding technology to create tightly bonded thin plates of plate A and plate B (B'), to place these two tightly bonded thin plates facing each other, and to form a hole between them. A perforated thermocouple material plate A is interposed therebetween, and its ends are, for example, electron beam welded to obtain an integrated heat flow sensor.

In this case, welding may be performed over the entire periphery of each plate or may be performed partially.

In such a one-piece structure heat flow sensor, the temperature drop in the heat resistance plate AA-A can be adjusted by the thickness of the heat resistance plate A interposed in the center or the density of the holes 3, 3, etc. ,
In the end, the output from the differential thermocouple can be made into the desired single shift.

The heat flow sensor shown in Fig. 2A does not use the heat resistance plate A, but consists of a perforated heat resistance plate A' and a plate B (B'), and like the sensor shown in Fig. 2A, the end portion is It is welded using a welding method such as electron beam welding.

The heat flow sensor shown in FIG. 2C is a folded version of the one shown in FIG. 2A and the one shown in yB.

The functions of the heat flow sensor shown in Figure 2 (c) are 1.
It is similar to that shown in Figure a.

Here, the perforated thermocouple material plate A is, for example, a thin plate in which holes 3, 3, etc. are arranged with desired hole diameters and their density is controlled, as shown in Fig. 3. .

The holes 3, 3, . . . may be arranged randomly or regularly.

Further, the holes 3, 3... can be easily formed by using photoetching technology.
Other techniques such as punching force reduction, electrical discharge machining, etc. may also be used.

The outside of the heat flow sensor (plate B,
The surface of B' has not been electrically insulated since the button was placed in the above state.

However, when a heat flow sensor is put into practical use, it is usually attached to a surface to be measured or embedded in an object.

In this case, if electrical insulation is not provided, there is a risk that the voltage generated by the differential thermocouple will leak, making it impossible to obtain a correct signal.

As a countermeasure for this, as shown in Figure 4a, aluminum or aluminum alloy is simultaneously hot-pressed on the outside of plate B to prepare two sheets of three-layer pressure bonding material A-B-C. Form the structure as shown in the figure.

Due to this structure, plate A, plate B, plate B and plate C are in close contact with each other in terms of metallographic structure, and are therefore electrically conductive.

Furthermore, the ends (periphery) of plates A-A'A are electrically contacted by welding means such as seriko beam welding, as described with reference to FIG.

Here, the aluminum strip or aluminum alloy of the plate C can be partially or completely anodized by anodizing in the state shown in FIG.

In this way, an alumite insulating film can be formed on the outer surfaces of the plates B and B' of the heat flow sensor shown in FIGS. I can do it.

As for the end portion (peripheral portion), there is no need to pay attention to electrical insulation because it is not in direct contact with the surface to be measured.

However, if it is buried inside an object, it will need to be electrically insulated, which is done by applying heat-resistant adhesive (inorganic) to the surrounding area.

This peripheral area is not an important part of the sensor during measurement, so it is sufficient that it is insulated, and there is no need to worry about uneven thickness.

On the other hand, the surfaces of plates B and B' are in direct contact with the object to be measured, and extremely smoothness is required.

In contrast, aluminum oxide films have extremely good uniformity and are suitable for this purpose.

Next, the results of experiments conducted on a concrete fabrication of a heat flow sensor having the structure shown in FIG. 4 among the above-mentioned heat flow sensors will be described.

FIG. 5 is a diagram showing the configuration of the heat flow sensor used in the experiment.

Here, A is a constantan plate (2smm (width) x 61
1 LrIL (length) x □, 5 mm (thickness)], B is a copper plate (25 mi 51n11LX611EX0.
11? +1), holes 3, 3, . . . are formed by photoetching as shown in FIG.

``Furthermore, the housing 4 is made of a copper alloy, and is used to fix the lead wires 2, 2 so that the internal heat flow sensor will not be corroded even if water is sprinkled on it.

An adhesive 5 having good thermal conductivity was filled in the gap between the broken housing and the heat flow sensor.

When this sensor was tested by attaching it to a water spraying surface, the output voltage was approximately 50P for a heat flow density of 10.000 kcal/-. The output is sufficiently readable.

I understand.

By the way, the estimated sensitivity when not using perforated thermal resistance plate A is ? The output voltage is expected to be 0.5 μV for a Qc density of 10.000 kcal/m″h, and with an output voltage of this level, measurement using a normal meter is extremely difficult.

As is clear from the explanation on the ground, according to the heat flow sensor of the present invention, the required sensitivity can be controlled by using a perforated plate made of a thermocouple material plate, and the surface is anodized. In some cases, excellent practical effects such as good electrical insulation can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a state in which heat flow density is measured by a heat flow sensor with a conventionally known structure. FIGS. The figure is a perspective view of a thermocouple material plate (thermal resistance plate) A' used in the heat flow sensor, and FIG. Figure 4 is a cross-sectional view showing a schematic configuration of a heat flow sensor according to the present invention manufactured using the members shown in Figure 4a, and Figure 5 is a cross-sectional view showing a specific example of the configuration of a heat flow sensor according to the present invention. 6 are diagrams showing the arrangement of holes formed in the thermocouple material plate A' used in the heat flow sensor shown in FIG. 5. A, A, B...thermocouple material plate, C...metal plate made of aluminum or aluminum alloy (metal plate capable of anodizing treatment), 3...hole.

Claims (2)

[Scope of utility model registration request] (1) The second and 30th thermoelectric material plates are electrically contacted with the first J) thermocouple material plate on the front and back surfaces of the first consideration material plate, which also serves as a heat resistance plate, to form a thin plate-shaped difference. In a heat flow sensor of a type that forms a dynamic thermocouple and measures the heat flow density by extracting the temperature difference between the front and back surfaces of the first thermocouple material plate as the output voltage of the dynamic thermocouple, the first thermocouple The first heat interposed between the material plate or the second and 30th thermocouple material plates is formed in a 40th thermocouple material plate made of the same material as the phantom material plate, with one or more holes formed therein. A heat flow sensor characterized by: (2) On each outer surface of the second and 30th thermoelectric material plates,
A heat flow sensor according to claim 1, which is formed by bonding metal plates each having an electrically insulating oxide film formed by anodic oxidation on its surface.