JPH0613467Y2 - Temperature sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a temperature-sensitive sensor used not only for detecting temperature but also for detecting gas concentration and humidity that cause a change in thermal conductivity of gas.

[Conventional technology]

The heat dissipation constant of a temperature-sensitive element such as a thermistor that is self-heated changes with the thermal conductivity of the atmospheric gas in which the element is placed. This phenomenon can be used to detect the ambient temperature as well as electrically detect the type of gas and the mixing ratio of different gases, and this method is used for gas chromatography and the like.
If the gas is regarded as water vapor in the air, the amount of water vapor in the air, that is, the absolute humidity can be detected because the heat conductivity of air is different from that of water vapor.

A temperature sensitive sensor utilizing such a change in thermal conductivity uses a temperature sensitive element such as a thermistor or platinum as a gas detecting element and a temperature compensating element for compensating the influence of ambient temperature, and a pair of both elements is used. It is customary to build it into a bridge circuit.

[Problems to be solved by the device]

By the way, in the conventional sensor, the detecting element and the temperature compensating element are built in independent metal cases, and both cases are installed as close to each other or as abutting. Therefore, in addition to mounting the terminal wire of the element for each metal case and the insulation structure of the terminal wire for each metal case,
There is a drawback in that the base for supporting both cases is further required and the sensor becomes large.

An object of the present invention is to provide a temperature-sensitive sensor which solves the above drawbacks by using a common base plate for mounting a pair of elements.

[Means for Solving the Problems]

In order to achieve the above object, when the temperature sensor of the present invention is used, a base plate, a pair of metal cases mounted on both sides of the base plate, the pair of metal cases are pierced through the base plate, and the one metal plate is passed through to the outside. Of the metal case on the side from which the terminal wires are drawn out, each of which has a plurality of terminal wires connected to each terminal wire and a pair of temperature sensitive elements which are individually housed in each metal case. A ventilation hole is opened in the portion, and the inside of the other metal case is hermetically sealed.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, a base plate 1 of a hermetically sealed stem (for example, TO-5) is pierced through an insulating material to hold the three terminal wires 2a, 2b, 2c. Each terminal wire 2
The a, 2b and 2c are short on the upper surface side of the plate 1 and long on the lower surface side so that the protruding lengths from both surfaces are different. When the above three terminal lines are distinguished as the first to third terminal lines 2a to 2c,
Using the third terminal wire 2c as a common terminal wire, the first and third terminal wires 2a, 2c are connected to the first temperature sensitive element 3 such as a thermistor on the upper surface side of the base plate 1 by a method such as welding, Second
The second temperature sensitive element 4 is connected to the third terminal wires 2b and 2c on the lower surface side of the base plate 1. On the upper surface side of the base plate 1, the first temperature sensitive element 3 connected to the first and third terminal wires 2a and 2c is covered, and the first metal case 5 is hermetically welded on the plate 1 to The second metal case 8 having the through holes 6a to 6c of each of the three terminal wires 2a to 2c and the ventilation hole 7 is welded to the lower surface side, and the second and third terminal wires are provided in the case 8. Second temperature sensitive element 4 connected to 2b, 2c
And the three terminal wires 2a through the insertion holes 6a through 6c.
2c is pulled out of the second metal case 8. Note that the terminal wire
Between the terminal wires 2a to 2c and the second metal case 8, the insulating material 9 such as resin is embedded in the insertion holes 6a to 6c of the second metal case 8 through which the terminals 2a to 2c are inserted, as shown in FIG. Insulate. Both elements 3 and 4 are separately housed in the metal cases 5 and 8 with the same base plate 1 in between, and the first metal case 5
The first temperature sensitive element 3 hermetically sealed inside is a temperature compensating element,
Second housed in a second metal case 8 having a vent hole 7
The temperature sensitive element 4 serves as a detection element. Further, the terminal wires 2a to 2c are pulled out from the second metal case 8 in only one direction, and the package form is a TO type.

[Effect of device]

As described above, in the case of this proposal, the base plate was shared for mounting the terminal wires of the temperature sensing element for detection and temperature compensation, so the metal case that houses each temperature sensing element was fixed on both sides of the base plate to provide a compact TO type sensor. It is possible to realize a temperature sensor, and by sharing the base plate to improve the temperature distribution characteristics by maintaining a thermal balance for both elements, it can be used for temperature sensor, humidity sensor, gas sensor, wind sensor, etc. It has the effect of achieving stability.

[Brief description of drawings]

FIG. 1 is a partially sectional perspective view showing an embodiment of the present invention, and FIG. 2 is a perspective view showing an appearance. 1 ... Base plate, 2a to 2c ... Terminal wire 3 ... Temperature sensitive element (temperature compensation element) 4 ... Temperature sensitive element (detection element), 5, 8 ... Metal case 7 ... Vent hole

Claims (1)

[Scope of utility model registration request] 1. A base plate, a pair of metal cases mounted on both sides of the base plate, and a plurality of terminal wires penetrating the base plate and further extending to the outside through the one metal plate, A pair of temperature-sensitive elements connected to each terminal wire and individually housed in each metal case, and a vent hole is opened in a part of the metal case on the side from which the terminal wire is drawn, and the other A temperature-sensitive sensor characterized by hermetically sealing the inside of a metal case.