JPH0277632A - Temperature measuring device - Google Patents

Abstract

PURPOSE:To measure a temperature with high accuracy by making uniform a temperature rise because of thermal conduction from each terminal by each radiating pattern, a heat-conductive insulating body and a heat-conductive radiating body provided in a printed circuit board. CONSTITUTION:When a thermocouple detects a heating temperature from a heating body, it generates a detecting signal indicative of the detecting temperature. The signal is transmitted via each connecting lead wire 10, terminal 2, terminal portion 3a, radiating pattern 4 and lead wire 5 to a temperature indicator within a main body 1 of the casing, where the temperature is indicated. Further, a thermal energy generated from an electronic circuit etc. is thermally conducted from each connecting lead wire 10 to the radiating pattern 4, and propagated to a heat-conductive insulating body 10. Consequently, the thermal energy is positively made uniform, while the lead wires 5 are respectively heated uniformly, so that the temperature can be measured with high accuracy.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to a temperature measuring device using a thermocouple incorporated in, for example, an electronic thermometer or its recorder, and particularly relates to The present invention relates to an input terminal connection device in a measuring device.

(Prior art) This type of electronic thermometer that has already been proposed
The thermocouple-based temperature measuring device built into the recorder is designed to isolate the thermocouple from the case body, which has a built-in temperature indicator, in order to prevent the input terminal from increasing in temperature due to heat conduction from the case body. Alternatively, the entire input terminal portion may be covered with a metal body to achieve uniform heat.

That is, this type of temperature measuring device using a thermocouple that has already been proposed is constructed as shown in FIGS. 3 and 4.

That is, in FIGS. 3 and 4, a terminal block is connected to the case body a containing a thermocouple temperature indicator via each connecting rod C, and this terminal block has a As shown in Figure 4, an electrical insulator d with a gutter-shaped cross section
is installed.

Moreover, a plurality of partition pieces e are formed on this insulator d, and the above-mentioned insulator d on which each partition piece e is located,
Each terminal f is fixed with a female screw g. Further, each connecting wire is connected to one end of each terminal f so as to be connected to the thermocouple (not shown), and each lead wire i is connected to the above-mentioned female screw g. It is provided so as to be connected to a temperature indicator built in the case body a.

Therefore, when the temperature measuring device using the thermal lightning pair described above detects the temperature of the heating body with the thermal lightning pair, it detects the temperature of the heating body through the connecting wire h1, each terminal f, and each lead Ij [i] built into the case body a. The measured temperature is displayed on the temperature display □ above.

(Problem to be Solved by the Invention) However, each of the terminals f, which individually connects each connection Ij[h to the thermocouple in the temperature measuring device described above, Although each terminal f is isolated from the case body a or covered with a metal body to equalize the heat, it not only overheats and rises in temperature due to heat conduction from each connection wire, but also has insufficient heat dissipation. Moreover, since the temperature rise due to heat conduction from each connection wire is different for each terminal f, the above-mentioned thermocouple temperature measuring device is unable to compensate for the cold junction of the heated thermocouple. (Reference junction compensation temperature),
For example, one temperature sensor measures the average temperature of each terminal F, and the thermoelectromotive force of each thermocouple corresponding to this temperature is subtracted from each input voltage to accurately measure the temperature of each terminal F. However, measurement errors tend to occur, making it difficult to measure temperature with high precision.

The present invention has been made in view of the above-mentioned circumstances, and the present invention has been made in view of the above-mentioned circumstances. It is an object of the present invention to provide a temperature measuring device that measures temperature with high precision while actively equalizing and dissipating heat with a heat conductive heat dissipating body and equalizing the heat of each terminal.

[Structure of the invention]

(Means for Solving the Problems and Their Effects) The present invention provides a temperature measuring device that measures temperature using a thermocouple.
A printed wiring board is provided on the terminal block connected to each terminal, each heat radiation pattern is arranged in parallel at each terminal part of this printed wiring board, and each end of each heat radiation pattern is connected to a temperature display inside the case body. Connect each lead wire to be connected, provide a heat conductive insulator and a heat conductive heat radiator on the printed wiring board so as to cover each heat radiating part of each heat radiation pattern, and connect each terminal connected to the thermocouple. The temperature rise due to heat conduction is actively equalized and radiated by each of the heat dissipation patterns laid on the printed wiring board, the heat conductive insulator, and the heat conductive heat radiator, and the temperature of each of the terminals is equalized. It is designed to measure temperature with high precision while also achieving high accuracy.

(Example) Hereinafter, the present invention will be described with reference to an illustrated embodiment.

In FIG. 1, reference numeral 1 denotes a terminal block provided via each connecting rod 9 from a case body I containing a temperature indicator using a thermocouple. 1a is formed, and each terminal 2 is attached to the terminal block 1 where each partition piece 1a is located. or,
Each terminal 2 has a connecting lead wire 1 connected to the thermocouple wire.
0 is connected. Furthermore, on the outside of the terminal block 1,
A flat printed wiring board (printed circuit board) 3 is provided to be connected to each terminal 2, and this printed wiring board 3
, each terminal portion 3a is attached to connect to each terminal 2 described above. Furthermore, on the printed wiring board 3, heat dissipation patterns 4 made of copper foil that also serve as heat equalization are arranged in parallel and connected to the terminal portions 3a, and in the middle of each heat dissipation pattern 4, , each heat dissipation section 4a is formed of square copper foil. Furthermore, each lead wire 5 is connected to the end portion 4b of each heat radiation pattern 4, and the other end of each lead wire 5 is connected to the case body! The case main body I displays the temperature with a built-in temperature indicator. Further, the printed wiring board 3 is provided with a sheet-like heat conductive insulator 6 and a heat conductive heat dissipating body 7 having heat dissipating fins 7a having a U-shaped cross section so as to cover each heat dissipation portion 4a of each of the heat dissipation patterns 4. It is provided so as to be in contact with and fixed with a mounting member 8.

Therefore, when the thermocouple detects the heating temperature from the heating body, the detection signal of the temperature detected by the thermocouple is transmitted to the connection lead wire 10, each terminal 2, the terminal portion 3a, each heat radiation pattern 4, the lead The temperature is transmitted through line 5 to the temperature display inside the case body I and displayed.

On the other hand, thermal energy generated from electronic circuits, etc. is thermally conducted from each of the connection lead wires 10 to each of the heat radiation patterns 4, and then propagated to the heat conductive insulator 6 and the heat conductive heat radiator 7, where it is actively dissipated. It is possible to uniformly heat and dissipate the heat, and to measure the temperature with high accuracy while uniformly heating the respective lead wires 5.

Next, if we explain the present invention using the heat conduction model and mathematical formulas shown in Figure 2, it can be expressed as follows (under normal specifications at room temperature, the main types of heat conduction, convection, and radiation heat conduction has that effect).

Now, to explain in detail the flow of heat for - terminals,
The temperature of the terminal block 1 is T1, and the temperature of the heat radiation pattern is T.
The temperature of terminal 2 is T3, the ambient temperature is T4, and the thermal resistance between them is as shown in Figure 2.
θ1. θ2. Assuming θ3゜θ, when there is no heat radiation pattern 4, heat conductive insulator 6, and heat conductive heat sink 7, T3 T4 - θ3/(θl+θ2+θ3)...
・It becomes (1).

On the other hand, when there is the heat radiation pattern 4, the heat conductive insulator 6, and the heat conductive heat radiator 7, the following equation is obtained.

However, / represents parallel resistance.

Therefore, it will be understood that if the thermal resistance θ4 is sufficiently small, the temperature of the terminal 2 will hardly rise compared to the surrounding air temperature.

As described above, in the present invention, since the temperature of each terminal 2 to which the thermocouple is connected decreases, the terminal temperature can be measured with high accuracy by the temperature sensor, and the temperature variation between the terminals 2 is reduced. Not only can the temperature of all the terminals 2 be accurately measured with - temperature sensors, but also highly accurate temperature measurement can be performed with thermocouples.

Note that the material of the heat conductive insulator 6 used in the present invention may be freely changed to silicon, polyester film, or a heat conductive insulating film integrally formed on the printed wiring board 3.

〔Effect of the invention〕

As described above, according to the present invention, in a temperature measuring device equipped with a terminal block that measures temperature using a thermocouple, a printed wiring board 3 is provided on the terminal block 1 and connected to each of the terminals 2, Each heat radiation pattern 4 is arranged in parallel corresponding to each terminal portion 3a of this printed wiring board 3, and each lead wire 5 connected to the temperature indicator of the case body l is connected to each end of each heat radiation pattern 4. Since a heat conductive insulator 6 and a heat conductive heat radiator 7 are provided in contact with the printed wiring board 3 so as to cover each heat radiating portion 4a of each heat radiating pattern 4, each of the terminals 2 connected to the thermocouple The heat radiation pattern 4, the heat conductive insulator 6, and the heat conductive heat radiator 7 installed on the printed wiring board 3 can actively radiate the temperature increase due to heat conduction from the printed wiring board 3. It is possible to measure the temperature with high precision while equalizing the heat of each lead wire 5 and dissipating the heat so as not to be affected by the heat generated from the terminal block 1.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing the main parts of the temperature measuring device of the present invention, FIG. 2 is a diagram for explaining the present invention in detail, and FIG. 3 is an already proposed temperature measuring device. 4 is an enlarged sectional view of section A in FIG. 3. 1...Terminal block, 2...Terminal, 3...Printed wiring board,
4... Heat dissipation pattern, 5... Lead wire, 6... Insulator, 7... Heat dissipation body. I4 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] In a temperature measuring device equipped with a terminal block that measures temperature using a thermocouple, a printed wiring board is provided on the terminal block connected to each terminal, and each heat radiation pattern is arranged in parallel on each terminal part of this printed wiring board. Then, each lead wire connected to the temperature indicator inside the case body is connected to each end of each heat radiation pattern, and a heat conductive insulator and a heat conductive heat radiator are connected to each heat radiation part of each heat radiation pattern on the printed wiring board. A temperature measuring device characterized by being provided in contact with and covering the temperature measuring device.