JPS5918338Y2 - temperature detection element - Google Patents

Description

[Detailed description of the invention] This invention combines a temperature-sensitive ferromagnetic material with a single Curie point corresponding to the temperature to be detected, a permanent magnet (having a Curie point higher than the temperature to be detected), and a reed switch. The present invention relates to a temperature detection element.

As such a temperature detection device, one is known that has a structure in which a permanent magnet and a temperature-sensing ferromagnetic material are arranged close to a reed switch.

In this case, not only the temperature-sensitive ferromagnetic material but also the permanent magnet and reed switch are exposed to heat from the detected part.

Therefore, temperature detection in a temperature range outside the usable temperature range of the reed switch becomes impossible.

In order to solve these drawbacks, the inventor of the present invention proposed a structure of a temperature detection element in which a reed switch is separated from a temperature-sensitive ferromagnetic material using a yoke, as shown in FIG.
Already suggested.

Referring to FIG. 1, one end of a yoke 2 consisting of two ferromagnetic plates is joined to the mutually opposing end surfaces of the temperature-sensitive ferromagnetic material 1, and the other end is joined to the mutually opposing end surfaces of the temperature-sensitive ferromagnetic material 1. It extends in the direction away from.

The ferromagnetic material constituting the yoke 2 is also selected from ferromagnetic materials having a Curie point sufficiently higher than the temperature of the detected part.

A permanent magnet 3 is attached midway in the extending direction of the yoke 2 so as to extend between both yokes.

The magnetic poles are oriented in a direction spanning both yokes.

The other end of each yoke 2 is made of ferromagnetic material (which also has a high Curie point like the yoke) at positions facing each other.
A ring member 4 is provided, and the axial end of the reed switch 5 is fitted into the hole of the ring member 4, so that the reed switch 5 is supported between both yokes.

The length of the yoke 2 is such that the reed switch 5 can be placed far enough away from the detected part to prevent the reed switch 5 from becoming usable due to heat from the detected part where the temperature-sensitive ferromagnetic material 1 is arranged. It needs to be the same length.

According to the temperature detection element described above, when the temperature of the detected part is lower than the Curie point of the temperature-sensitive ferromagnetic material 1, the magnetic flux from the permanent magnet 3 passes through the closed magnetic path between the yoke 2 and the temperature-sensitive ferromagnetic material 1. However, when the temperature exceeds one Curie point, the temperature-sensitive ferromagnetic material 1
exhibits paramagnetism, the magnetic flux from the permanent magnet 3 flows through a closed magnetic path between the yoke 2 and the reed switch 5, and as a result, the reed switch 5 is closed.

In this way, temperature can be detected as the opening and closing operations of the reed switch 5.

Here, the ring member 4 is for facilitating the flow of magnetic flux from the yoke 2 to the reed switch 5, and there is no particular need to use it, but if there is no ring member, the reed switch 5 can be connected to the permanent magnet 3. This is equivalent to shortening the yoke 2 by that much, and the temperature difference between the detected part and the reed switch is narrowed.

By the way, in order to improve the thermal responsiveness of the temperature sensing element as described above, there is a method of reducing the volume of the temperature sensing ferromagnetic material 1.

However, when the volume is reduced, the amount of magnetic flux that can be controlled decreases, so the temperature difference between the opening and closing operations of the reed switch 5 increases, and there is a limit to the volume reduction.

In order to solve this problem, the present invention provides a temperature sensing element of this type equipped with heating fins for the purpose of improving thermal responsiveness in the case of temperature sensing of steam flow.

FIG. 2 shows an embodiment of the present invention, in which heating fins (for example, made of aluminum) are shown.

) 6 is attached to the temperature-sensitive ferromagnetic material 1, which has a surface that is perpendicular to the yoke 2 and inclined with respect to the direction in which the yoke extends.

8 indicates the flow of hot air. As a result, the hot air flows along the heating fins and concentrates on the temperature-sensitive ferromagnetic material 1.
Improves thermal response.

On the other hand, since the heating fins 6 have an inclination with respect to the airflow,
There is almost no turbulence in the flow of air.

In FIG. 3, another heating fin 7 is arranged with an inclination opposite to that of the heating fin 6, so that the hot air flow 8 is concentrated on the temperature-sensitive ferromagnetic material. Furthermore, thermal responsiveness is improved.

Note that this additional heating fin 7 naturally has the following properties:
It is attached to the yoke 2 apart from the temperature-sensitive ferromagnetic material 1.

FIG. 4 shows an example of the mounting structure of heating fins when the temperature-sensitive ferromagnetic material 1 is in the shape of a round bar, and as shown in the figure, the fins 6
If you form a recess corresponding to the round bar in the center of ',
It can be attached by fitting a ferromagnetic material with a round bar shape into this recess.

As explained above, according to the present invention, it is possible to obtain a temperature detection element in which the reed switch is not exposed to heat from the detected part, and therefore, it is possible to obtain a temperature detection element that does not expose the reed switch to heat from the detected part. temperature can also be detected, extending the life of the reed switch.

Furthermore, in the present invention, both ends of the reed switch in the axial direction are
Since the reed switch has a structure in which the reed switch is supported by two yokes and can be easily aligned, the temperature detection element can be assembled extremely easily.

Further, according to the present invention, it has a temperature-sensitive ferromagnetic material, a permanent magnet, a reed switch, and two yokes, and both ends of the reed switch in the axial direction are supported by the ends of the two yokes. In the temperature detection element having such a structure, it is possible to obtain a heat absorption structure that can improve thermal response when detecting the temperature of a hot air flow.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an example of a temperature detection element to which the present invention is applied, FIG. 2 is a side view showing an embodiment of the present invention, and FIG.
FIG. 4 is a side view showing another embodiment of the present invention.

Claims (1)

[Scope of utility model registration request] A temperature-sensitive ferromagnetic material having a Curie point corresponding to the temperature to be detected and to be placed in the detected part, and a detection member bonded to the opposite end surface of the temperature-sensing ferromagnetic material and extending in a direction away from the temperature-sensing ferromagnetic material. Two yokes made of ferromagnetic material with a Curie point sufficiently higher than the desired temperature, and a detection sensor installed between the two yokes in the middle of the extending ends of the two yokes, with the magnetic pole direction spanning between the yokes. A temperature sensing element having a permanent magnet having a Curie point sufficiently higher than the desired temperature, and a reed switch whose axial ends are each supported between mutually opposing positions at each extending end of the two yokes, A temperature sensing element characterized in that a heat absorption fin having a surface perpendicular to the yoke surface and inclined with respect to the yoke extending direction is attached to the temperature sensing ferromagnetic material.