JPH037891B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a temperature detector that detects the temperature of a portion to which a high voltage is applied.

[Conventional technology]

Conventionally, as this type of detector, for example, there has been a temperature detector described in the catalog "General Industrial Temperature Sensors" of Sogo Denki Co., Ltd.

This temperature sensor is a temperature resistor that changes resistance in proportion to the temperature of the temperature-measuring part, or a thermocouple that generates an electromotive force proportional to the temperature, when the heat-sensitive part is attached to the temperature-measuring part. It's summery.

These conventional temperature detectors are not designed to measure the temperature of parts to which high voltage is applied, so when measuring the temperature of parts to which high voltage is applied, for example, the output signal of the heat sensitive part must be insulated before reception. The drawback was that signals had to be exchanged and temperature measurements had to be taken on the side.

[Summary of the invention]

This invention was made to eliminate the drawbacks of the conventional devices as described above, and it uses an insulator with low thermal resistance to connect the heat-sensitive element, which exhibits electrical characteristics depending on the temperature, and the part in contact with the temperature-measured part. The purpose of the present invention is to provide a temperature sensor which has a structure in which the heat-sensitive element side is grounded and the temperature of the temperature-measured part and the temperature of the heat-sensitive element side is reduced, and is insulated from high voltage. .

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. Figure 1 shows the principle of dielectric breakdown.
is sandwiched between electrodes 1 and 2, and a power source 4 is connected between both electrodes. If the voltage of the power supply 4 is increased in this state, the insulator 3 will cause dielectric breakdown when the applied voltage reaches a certain level, but if a gap 5 is created in this insulator, the electric field will be concentrated, and the dielectric breakdown voltage will increase. known to decrease. In other words, when a gap occurs in an insulator, the withstand voltage decreases. For this reason, in the method of insulating the temperature sensing part by directly covering it with an insulator, it is necessary to create a structure that does not create any gaps between the insulator and the temperature sensing part, but the temperature of the insulator This occurs due to the difference between the expansion caused by the heat-sensing part and the expansion of the heat-sensing part, or due to a failure in covering the temperature-sensing part with an insulator.
It is necessary to consider the distance between the two, and as a result, restrictions are placed on the materials and shapes of the insulating materials and temperature sensing parts.

Figure 2 is a diagram showing the principle of the present invention, Figure 3 a, b
1 to 3 in the drawings are a plan view and a vertical sectional view showing the structure of an embodiment of the present invention, 1 to 3 in FIG. 1 and 1 to 3 in FIG.
2 corresponds to the surface that comes into contact with the live part, and 1
indicates a ground electrode, and 3 indicates an insulator. The reason why the upper part of 3 in the figure has a wavy structure is to increase the creepage distance, and 6 indicates a heat-sensitive element. Reference numerals 7 and 8 indicate output signal terminals of the heat-sensitive element, 9 indicates a ground electrode terminal, and 10 indicates a temperature-measuring portion. FIG. 3 shows an example of the structure of a device that is embedded in a temperature-measuring part to detect temperature, and the conductor 2 is embedded with a part of the upper part left. Since there is only a difference in potential between the conductor 1 and the heat-sensitive element 6, which is generated by the heat-sensitive element, there is no need to take into account the drop in withstand voltage due to the gap that occurs in the insulator or between the heat-sensitive part and the insulator. It is sufficient to use a material that focuses on being an insulating material with good thermal conductivity. Since 1 to 3 and 6 above are made of materials with low thermal resistance, the temperature of the temperature-measuring part 10 and the temperature of the temperature-sensing part are the same, and the terminals 6 and 7 receive electrical signals proportional to the temperature of the temperature-measuring part. It appears as an output signal from the heat-sensitive element, making it possible to measure temperature.

〔Effect of the invention〕

As described above, according to the present invention, an insulator with low thermal resistance is sandwiched between conductors with low thermal resistance, one of which is in contact with the temperature-measured part, the other is grounded, and the heat-sensitive element is provided on the ground side. This has the effect that the part to be measured and the heat-sensitive element can be easily insulated, and the temperature can be measured at the part to which a high voltage is applied.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing the principle of breakdown of an insulator, Fig. 2 is a circuit diagram showing the principle of the present invention, Fig. 3 a, b
1 is a plan view and a longitudinal cross-sectional view of a temperature sensor according to an embodiment of the present invention. Reference numeral 1 indicates a grounding electrode, 2 a contact surface of a part to be measured, 3 an insulator, 6 a heat-sensitive element, 7 and 8 output terminals of the heat-sensitive element, 9 a ground terminal, and 10 an object to be measured. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A heat-sensitive element for temperature measurement, a ground electrode arranged around this heat-sensitive element, an electrical insulator with low thermal resistance arranged around this ground electrode, and the above-mentioned materials around this electrical insulator. A temperature sensor equipped with an outer electrode that is placed opposite to a ground electrode and in contact with the object to be measured.