JPH04115131A - Temperature detecting device - Google Patents

Abstract

PURPOSE:To obtain a detecting device characterized by excellent heat response and high reliability by forming a measuring surface as a flat surface or a curved surface having a constant curvature, and fixing a heat sensitive element to the inner wall of the measuring surface of a metal cap having airtight property. CONSTITUTION:A thermister element 10 is provided in a metal cap 11 and attached so that the thermister element is in contact with the inner wall surface of a measuring surface 11a with a pushing plate 12. The opening part of the metal cap 11 is closed with a metal base 13. A space part 14 in the cap 11 is evacuated or filled with nitrogen gas which is inactive gas. Lead wires 15 which are connected to the element 10 are connected to terminal rods 17 which are fixed to the hole parts provided in the base 13 through insulating and sealing glass 16 in the metal cap 11 by spot welding. Since a part other than the surface in contact with the metal wall surface acts as the heat insulating space, heat response is improved. Since the oxidation of the lead wires is prevented, the lead wires can be made to be the thin wires.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a temperature detection device that measures temperature while being in close contact with an object to be measured.

[Prior Art] FIG. 5 shows a cross-sectional view of a conventional contact-type temperature detection section 1 using a thermistor element as a heat-sensitive element.
is embedded together with a filler 4 made of heat-resistant resin inside a heat-sensitive head 3 made of a metal block made of copper, for example. This temperature detection unit 1 is attached to the center of a burner of a gas stove, for example, and is pressed against the bottom of the pot by the elasticity of a spring 5 to detect the temperature of the bottom of the pot. , is used to automatically stop the gas supply.

[Problems to be Solved by the Invention] As described above, the temperature detection unit 1 that is attached to a gas stove, rice cooker, etc. to detect the temperature at the bottom of a pot has a detection unit for the heat-sensitive head 3 and the filling material 4 made of a metal block. The heat capacity of 1 itself is large (there is a problem that the response is not good. Also,
Because it can reach high temperatures of up to 300"C,
There are restrictions on the members to be used, and in particular, it is difficult to make the lead wire inside the temperature detection section 1 small in diameter to prevent disconnection due to oxidation.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks and provide a temperature detection device that has good thermal response and high reliability.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the temperature detection device according to the present invention has a measurement surface that is a flat surface or a gently curved surface with a constant curvature, and a metal cap that has airtightness. A heat-sensitive element is fixed to the inner wall of the measurement surface of the apparatus, a lead wire connected to the heat-sensitive element is drawn out of the metal cap, and the inside of the metal cap is evacuated or filled with an inert gas. It is something.

[Function] The temperature detection device having the above configuration has a heat sensitive element fixed to the inner wall of a sealed metal cap, and the inside is filled with an inert gas or made into a vacuum, so that the temperature detection device has a small heat capacity, good responsiveness, and high temperature detection. The lead wire will not be oxidized even in the

[Example] The present invention will be explained in detail based on the example illustrated in FIGS. 1 to 4.

FIG. 1 is a cross-sectional view of the first embodiment, in which a thermistor element 10 is provided in a metal cap 11 in a temperature detection section 1, and is held by a pressing plate 12 so as to be in contact with the inner wall surface of a temperature measurement surface 11a. installed. metal cap 1
1 is closed by a metal base 13, and a space 14 inside the metal cap 11 is evacuated or filled with an inert gas such as nitrogen gas. A lead wire 15 connected to the thermistor element 10 is connected within the metal cap 11 by spot welding or the like to a terminal rod 17 fixed to a hole provided in the base 13 via an insulating sealing glass 16. .

For example, the thermistor element 10 has a diameter of 1 mm or less,
The lead wire 15 has a diameter of approximately 0.1 mm. The lead [15] is not oxidized because the metal cap 11 is filled with vacuum or inert gas. After attaching the thermistor element 10 with the holding plate 12, applying special heat-resistant paint, high-temperature adhesive, etc. around the thermistor element 10 increases the adhesion between the metal wall surface and the thermistor element 10, and further improves thermal responsiveness. can be increased.

FIG. 2 shows a second embodiment, in which the thermistor element 10 is placed on the top of a spring-like pressing fitting 18 that rises from the base 13 without using the holding plate 12, and is brought into contact with the metal cap 11. , the thermistor element 10 is pressed against the inner wall of the measurement surface 11a.

FIG. 3 shows a third embodiment in which the metal tube 19 is connected to the base 13 through the insulating sealing glass 16 without using the terminal bar 17.
The lead wire 15 is inserted through the metal tube 19,
The end of the metal tube 19 is sealed with high temperature solder 20. In this way, by using the metal tube 19, the lead wire 15 can be connected to the metal cap 1 during processing as in the previous embodiment.
It can be processed without having to store it in one place, which is convenient for assembly.

FIG. 4 shows the usage state of the temperature detection section 1 according to the present invention,
The temperature detection section 1 is fitted into the guide tube 21 and urged upward by a spring 22 to contact, for example, a pot bottom 23.

[Effects of the Invention] As explained above, the temperature detection device according to the present invention has a small heat capacity (by filling the metal cap containing the temperature sensing element with a vacuum or an inert gas), Since the area other than the surface acts as a heat insulating space, the thermal response is improved, and oxidation of the lead wire is prevented, so the lead wire can be made into a thin wire.

[Brief explanation of drawings]

Drawings 1 to 4 show embodiments of the temperature detection device according to the present invention, and FIGS. 1, 2, and 3 are sectional views of the first, second, and third embodiments, respectively. FIG. 4 is an explanatory diagram of the state of use, and FIG. 5 is a cross-sectional view of the conventional example. Reference numeral 1 is a temperature detection section, and 10 is a thermistor element. 11 is a metal cap, 12 is a holding plate, 13 is a base,
14 is a space, 15 is a lead wire, 16 is an insulated sealing glass, 17 is a terminal bar, 18 is a pressing fitting, and 9 is a metal tube. Figure 1

Claims (1)

[Claims] 1. The measurement surface is a flat surface or a gently curved surface with a certain curvature, a heat-sensitive element is fixed to the inner wall of the measurement surface of an airtight metal cap, and a lead wire connected to the heat-sensitive element is attached to the metal cap. A temperature detection device, characterized in that the metal cap is pulled out to the outside, and the inside of the metal cap is evacuated or filled with an inert gas.