JPS62278421A - Temperature sensor - Google Patents

Abstract

PURPOSE:To prevent a thermistor from jumping or being broken even though a vibration is applied thereto by fixing the thermistor and an insulating pipe to each other by a heat resisting cement. CONSTITUTION:A pair of the lead-out wires 12 of a thermistor 10 are welded to lead wires 14, which are passed through a two-holed insulating pipe 16 and the pipe 16 and the thermistor 10 are fixed to each other by using a heat resisting cement 18. Further, the cement 18 is filled in the holes of the insulating pipe 16 to fix the wires 14 to the insulating pipe 16. The insulating pipe 16 is fixed to a metal pipe 20 by using a heat resisting cement 22. The metal pipe 20 is connected to a fixing metal 26 and a gasket 28 is mounted to the metal 26. The lead wires 14 are connected to sensor output takeout wires 30 which are stranded wires and passed through an auxiliary ring 32 made of silicone rubber. The ring 32 is fitted in the metal pipe 20 and caulked by a caulking portion 34 to be fixed to the metal pipe 20, constituting a temperature sensor S.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a temperature sensor that measures the temperature of gas or the like.

"Prior Art" Conventionally, various temperature sensors have been used to measure and detect gas salt, liquid temperature, water temperature, and the like.

One type of temperature sensor is a temperature sensor in which a thermistor is protruded from the tip of an insulating tube, and the insulating tube is held in a metal tube in order to further detect the temperature difference F1.

[Problems to be Solved by the Invention] By the way, when vibration is applied to the above-mentioned temperature sensor, the vibration may cause the thermistor to jump or the thermistor's lead wire may resonate, causing the risk that the thermistor or the thermistor's lead wire may be destroyed. was there.

To prevent this, there are some types in which the thermistor is fixed to the tip of the insulating tube by filling the area around the thermistor with a resin such as epoxy or fluororesin.

However, as mentioned above, when the thermistor is fixed with resin, the heat resistance of the resin is low (the usage limit of epoxy is 200℃,
Fluororesin cannot be used at high temperatures (300°C).

In addition, in order to ensure heat resistance, there are products in which the thermistor is fixed by filling it with powder such as talc, but it is difficult to set the position of the thermistor, and external force is applied to the thermistor during filling, causing damage to the thermistor or the thermistor being pulled out. line(
(Because it is thin, its strength is low).

(Means for solving the problems) The present invention employs the following means to solve the above problems.

111. The gist of the present invention resides in a temperature sensor equipped with an insulating tube having a thermistor at its tip, characterized in that the thermistor and the insulating tube are fixed with heat-resistant cement.

Here, the resistance value of the thermistor changes greatly depending on the temperature. There are two types of thermistors: those with a simple temperature coefficient (NTC) and those with a positive temperature coefficient (PTC).
, resistance value changes rapidly in a certain temperature range (CTR)
There are several types, but in the present invention, a rotary type can also be used, and the type can be selected according to the purpose.

The insulating tube is used to insulate and protect the thermistor's lead wire, and two types of insulating tubes are usually used.

The heat-resistant cement is not particularly limited as long as it has excellent heat resistance, such as alumina cement, special alumina cement, and phosphate cement.

Note that the thermistor is usually protected by a metal tube with one end closed.

[Function] Even if vibrations are applied to the temperature sensor of the present invention, since the thermistor and the insulating tube are fixed by heat-resistant cement, the thermistor may jump or the thermistor lead wire,
The lead wires do not resonate, and the position can be set more reliably.

In addition, heat-resistant cement has excellent heat resistance, so it can be used at higher temperatures (
Vibration resistance does not deteriorate even when used at temperatures (300 to 600°C).

[Implementation (v4)] An embodiment of the present invention will be described with reference to the sectional view in FIG. 1 and the partially cutaway view in FIG. 2.

First, as shown in FIG.
Weld to the lead wire 14 of mmφ, and connect the lead wires 1 and 1 to 2.
Pass through the insulating tube 16 in the hole, and connect the insulating tube 16 and the thermistor 10.
and are fixed using heat-resistant cement 18. Also, heat-resistant cement 18 is filled into the hole of the insulating tube 16 to fix the lead wire 14 to the insulating tube 16. The reason why the lead wire 12 is welded to the lead wire 14 is because the lead wire 12 is too thin and twisted.

Furthermore, as shown in FIG. 2, this insulating tube 16 is fixed to a metal tube 20 using heat-resistant cement 1-22. This metal tube 20
A fixing metal fitting 26 having a threaded part 24 for mounting is attached at the bottom.
It is united with. Also, the gasket 2 is attached to the fixing metal fitting 26.
8 is installed. The above lead wire 14 is made of twisted wire! ), and is passed through an auxiliary link 32 made of silicone rubber. The auxiliary ring 32 is fitted into the metal tube 20, and is fixed to the metal tube 20 by being crimped by the crimping portion 34, thereby forming the temperature sensor S.

Since the temperature sensor S of this embodiment has the above structure, even if vibration is applied to the temperature sensor S, the thermistor 10 will not jump or the lead wire 12 will not resonate due to the vibration. thermistor 10
and its leader line 12 will not be destroyed.

In addition, since the heat-resistant cement 18 has excellent heat resistance, the temperature sensor S of this embodiment can operate at a higher temperature (300°C) than the conventional temperature sensor.
Even when used at temperatures up to 600°C, the vibration resistance does not deteriorate and it can be used stably and conveniently.

Furthermore, since heat-resistant cement)-18 and -22 have better thermal conductivity than resin, the temperature sensor of the present invention has excellent responsiveness (heat-resistant cement has a thermal conductivity that is 1/2 that of resin such as epoxy).
0 times or more).

Since the thermistor 10 is fixed to the insulating tube 16 in advance, it is easy to set the position of the thermistor 10 during assembly, and no external force is applied to the thermistor 10 when joining the insulating tube 16 and the gold α tube 20. .

In addition, in the temperature sensor S of this embodiment, since the lead wire 14 and the insulating tube 16 are firmly fixed with the heat-resistant cement 18, even if a tensile force is applied to the lead wire 14,
The thermistor 10 or the thin lead wire 12 of the thermistor 10 will not be destroyed, so handling of the temperature sensor S is very easy.

[Effects of the Invention] In the temperature sensor of the present invention, even when vibration is applied, the thermistor and the insulating tube are fixed by flJ4 thermal cement, so the thermistor does not jump or the thermistor's lead wire and lead wire resonate. , the thermistor will not be destroyed.

Since heat-resistant cement has excellent heat resistance, it has been found that
Even when used at temperatures of 300 to 600°C, the vibration resistance does not deteriorate and it can be used stably.

Furthermore, since heat-resistant cement has better thermal conductivity than resin, the temperature sensor of the present invention has excellent responsiveness.

Since the thermistor is fixed to the insulating tube with heat-resistant cement in advance, it is easy to set the position of the thermistor during assembly, and no external force is applied to the thermistor when connecting the insulating tube and the metal tube. The thermistor is not destroyed during sensor assembly.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an insulating tube according to an embodiment of the present invention, and FIG. 2 is a partially cutaway view of the embodiment. S...Temperature sensor 10...Thermistor 12...
・Leader wire 14...Lead wire 16...Insulated tube
18...Heat-resistant cement 20...Metal pipe

Claims (1)

[Scope of Claims] A temperature sensor equipped with an insulating tube having a thermistor at its tip, characterized in that the thermistor and the insulating tube are fixed with heat-resistant cement.