JPS5846815B2 - temperature sensitive switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a temperature-sensitive switch using a ferromagnetic material whose axis of easy magnetization changes with temperature.

It is known that among alloys containing rare earth metals, there are materials whose axis of easy magnetization changes depending on temperature.

Alloys containing rare earth metals, such as RCo5, R2Co1□
(R represents a rare earth metal) is known as a high-performance permanent magnet material.

However, a material whose axis of easy magnetization changes with temperature as described above cannot be used as a permanent magnet material.

The present invention was made by focusing on a material whose axis of easy magnetization changes depending on the temperature.

Figure 1 shows NdCo5, Yl-XNdXC05 (X=0
．． 75, X=0.50. , X=0.25) and Pr
The data of Co.

In the figure, the horizontal axis direction indicates the temperature (0K), and the vertical axis direction indicates the included angle (β) between the C-axis direction of the magnetic material and the easy magnetization axis direction.

According to the figure, β of NdCo changes rapidly from around 250°.

, 5 Nd□, 5 Co5, etc., it changes gradually.

FIGS. 2 and 3 show temperature changes in the easy axis direction of other alloys.

Figure 2 shows the case of RCo5, Figure 3 shows the case of R2Co1f), and in the figure, P shows the case where the axis of easy magnetization is the Basal plane (
BASAL plane), A is along the C axis, C
shows a case where the easy axis direction of magnetization is between the C axis and the BASAL plane, and a conical shape is drawn.

Solid lines and circles indicate measured directions, dotted lines indicate expected directions.

As mentioned above, among alloys containing rare earth metals, there are some whose axis of easy magnetization changes depending on temperature, and the present invention provides a temperature-sensitive switch using a material whose axis of easy magnetization changes depending on temperature. It is.

Among the materials shown in FIGS. 1 to 3, materials whose axis of easy magnetization changes rapidly with temperature are suitable for temperature-sensitive switches.

Note that materials that work at various temperatures can be obtained by combining two or more types of rare earth metals or by changing the composition ratio of the metals.

Bimetals, combinations of temperature-sensitive ferrite and reed switches, combinations of thermocouples and relays, etc. have been conventionally used as temperature-sensitive switches, but the purpose of the present invention is different from the above-mentioned conventional temperature-sensitive switches. The purpose of this invention is to provide a new temperature-sensitive switch based on the operating principle.

The object of the present invention is to arrange a reed switch and a material whose axis of easy magnetization changes depending on temperature in the magnetic path of a permanent magnet,
Utilizing the property that as the axis of easy magnetization of the material changes due to temperature, the direction in which magnetic flux is easy to pass changes, the magnetic flux passing through the reed switch is changed depending on temperature,
This is achieved by opening and closing a reed switch.

Next, it will be explained in detail with reference to the drawings.

FIG. 4 shows a temperature sensitive switch according to an embodiment of the invention.

In the figure, 1 is a permanent magnet, 2 is a material whose axis of easy magnetization changes depending on temperature, and 3 is a reed switch.

A material 2, a permanent magnet 1, and a reed switch 3 whose axis of easy magnetization lies within the Ba5al plane at low temperatures and faces in the C-axis direction at high temperatures are arranged as shown in the figure.

At low temperatures as shown in Figure 4a, if the axis of easy magnetization of material 2 is placed in the direction shown by the arrow, most of the magnetic flux emitted from permanent magnet 1 will pass through material 2, and only a small amount of magnetic flux will pass to the reed switch 3 side. .

Therefore, the reed switch remains in the 11 open 11 state.

When the temperature reaches a high temperature as shown in FIG. 4, the direction of the axis of easy magnetization of the material 2 changes in the direction of the arrow, so that most of the magnetic flux of the permanent magnet 1 passes through the reed switch 3.

Therefore, the reed switch 3 is in the "closed 11" state.

Next, another embodiment of the present invention shown in FIG. 5 will be described.

In this embodiment, a material 2 whose axial force of easy magnetization changes depending on temperature is placed between two permanent magnets 1a and lb.

At a low temperature as shown in FIG. 5a, a magnetic path passing through the permanent magnet 1a, the material 2, the permanent magnet 1b, and the reed switch 3 is formed, and the reed switch 3 is in the 11 closed 11 state.

When the temperature is high as shown in FIG. 5, the axis of easy magnetization of the material 2 changes in the direction of the arrow, so that the permanent magnet la.

No magnetic path is formed from 1b through material 2, and permanent magnet 1a
, 1b pass through only a portion of the reed switch 3 as shown by the dotted line, and the reed switch 3 is in the "open" state.

In addition, in Figures 4 and 5, if you change the arrangement direction of the material 2, the operation will be reversed (that is, in Figure 4, 1 closed at low temperature and 1' open at high temperature, and in Figure 5, 1 open at low temperature and 1' open at high temperature). Closed “1)
A temperature-sensitive switch that performs this can be easily manufactured.

Conventionally, a temperature-sensitive ferrite switch has been known that is used for the same purpose and has the same structure as the temperature-sensitive switch of the present invention, but in this temperature-sensitive ferrite switch, the temperature-sensitive ferrite used is magnetic at the Curie temperature. This takes advantage of the property of losing .

This temperature-sensitive ferrite has a magnetic flux density of 3000 to 4000G.
On the other hand, in material 2 used in the present invention, 100OOG
The above manufacturing is also possible, and the material of the present invention has a higher magnetic flux density than conventional temperature-sensitive ferrite.

Therefore, the temperature-sensitive switch of the present invention can be miniaturized, and since it is entirely made of metal, it has the advantage of good heat conduction and quick response to temperature.

[Brief explanation of drawings]

Figure 1 shows NdCo5, Yl -X, Nd) (C05
and temperature change in the easy magnetization axis direction of PrCo5, Figure 2 shows temperature change in the easy magnetization axis direction of alloy RCo5 containing rare earth metals, Figure 3 shows temperature change in the easy magnetization axis direction of alloy R2Co containing rare earth metals, FIG. 4 is a block diagram of a temperature-sensitive switch according to an embodiment of the present invention, and FIG. 5 is a block diagram of a temperature-sensitive switch according to another embodiment of the present invention. In the figure, 1 is a permanent magnet, 2 is a material whose axis of easy magnetization changes depending on temperature, and 3 is a reed switch.

Claims (1)

[Claims] 1. A temperature-sensitive device characterized by arranging a material whose axis of easy magnetization changes depending on temperature and a reed switch in the magnetic path of a permanent magnet, and opening and closing the reed switch by changing the magnetic flux passing through the reed switch depending on the temperature. switch.