JPS5840502Y2 - 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 the heat from the detected part.

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

SUMMARY OF THE INVENTION In view of the above points, it is an object of the present invention to provide a structure of a temperature detection element that can detect the temperature of a detected part that generates a high temperature that makes the reed switch unusable.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.

FIG. 1 is a perspective view showing the structure of an embodiment of the present invention, and FIG. 2 is a top view thereof.

Referring to both figures, 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 separated from the temperature-sensitive ferromagnetic material 1. extending in the direction.

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 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 unusable 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 above embodiment, 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 is transferred to the yoke 2 and the temperature-sensitive ferromagnetic material as shown by the solid line Φ1 in the figure. It flows in a closed magnetic path with the magnetic body 1, but when the temperature reaches the Curie point or higher, the temperature-sensitive ferromagnetic body 1 exhibits paramagnetism, so the magnetic flux from the permanent magnet 3 is as shown by the dotted line Φ2 in the figure. York 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 if there is no ring member, the reed switch 5 must be brought closer to the permanent magnet 3. This is equivalent to shortening the yoke 2 by that much, which is disadvantageous because the temperature difference between the detected part and the reed switch becomes narrower.

FIG. 3 is a top view of another embodiment of the present invention, in which the ring member 4' is provided so as to pass through the yoke 2 and protrude to both sides.

Note that the reed switch is not shown.

As is clear from the description of the embodiments above, according to the present invention, the reed switch 5 can be placed sufficiently far away from the detected part to the extent that the reed switch 5 does not become unusable. Can be easily supported.

In addition, since the reed switch 5 is supported at both ends in the axial direction by the ring member 4 made of a ferromagnetic material, when the temperature-sensitive ferromagnetic material 1 exhibits paramagnetism, one side of the magnetic flux from the permanent magnet 3 is It is easy for the yoke to flow into one lead end and to flow out from the other lead to the other yoke.

Therefore, the contacts of the reed switch 5 can be reliably closed when the temperature rises, and the temperature response is good.

Moreover, the lead wires can be easily drawn out from the leads coming out from both ends of the reed switch 5.

Furthermore, since the end of the reed switch 5 is fitted and supported in the hole of the ring member, there is no need for alignment and assembly is easy.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of one embodiment of the present invention, FIG. 2 is a top view thereof, and FIG. 3 is a top view of another embodiment. 1... Permanent magnet for temperature sensing, 2... Yoke, 3... Permanent magnet, 4... Ring member, 5... Lead switch.

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 permanent magnet having a Curie point sufficiently higher than the temperature to be detected, and a ring made of a ferromagnetic material having a Curie point sufficiently higher than the temperature to be detected, which is provided at mutually opposing positions at each extending end of the two yokes; and a reed switch whose ends are fitted and supported by both ring-shaped holding members so as to be disposed between the two yokes. A temperature detection element that can detect temperature by separating light so that it is not affected by heat.