JPS6023878Y2 - heat sensitive reed switch - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a heat-sensitive reed switch that controls a magnetic circuit including a permanent magnet to open and close a reed switch by magnetically transforming a heat-sensitive magnetic material at around one Curie temperature.

Conventionally, regarding this type of switch,
27 trout are known.

This switch consists of two lead pieces 1 as shown in Figure 1.
1 and 11 enclosed in a cylindrical body 12
3, and the reed piece 11 along the reed switch 13.
A first cylindrical permanent magnet 14 is externally fitted at a position corresponding to one of the reed pieces 11, and a second cylindrical permanent magnet is externally fitted along the reed switch 13 at a position corresponding to the other reed piece 11. 15, and a cylindrical temperature-sensitive magnetic body 16 disposed between the cylindrical permanent magnets 14 and 15.

In this temperature-sensitive reed switch, when the ambient temperature is below one Curie temperature of the cylindrical temperature-sensitive magnetic body 16, that is, indicates a ferromagnetic state, the reed contact is closed; When the temperature exceeds one level, that is, when a paramagnetic state is exhibited, the reed contact operates to open, and generally high accuracy is required for this operating temperature.

However, when looking at the parts that make up this switch, there are variations in the magnetic force of the permanent magnet, the Curie temperature of the temperature-sensitive magnetic material, and the emotional value of the reed switch, so it is difficult to simply assemble these parts. However, this method had the drawback that it caused large variations in operating temperature and was unable to meet the required temperature accuracy.

This invention proposes a heat-sensitive reed switch aimed at eliminating the above-mentioned drawbacks, and as shown in FIG. A switch 1, and two bipolar magnetized cylindrical permanent magnets 4a surrounding the outer periphery of the reed switch 1 and arranged so that different magnetic poles of their opposing surfaces face each other.
, 4b, and a semi-cylindrical thermosensitive magnetic body 5 disposed between the cylindrical permanent magnets 4at4b.

Note that an inert gas is sealed inside the glass tube 3.
Further, the cylindrical permanent magnet 4a is arranged at a position corresponding to the lead piece 2a, and the cylindrical permanent magnet 4b is arranged at a position corresponding to the lead piece 2b.

The basic operation of this heat-sensitive reed switch will be explained below with reference to FIG.

When the ambient temperature is below the Curie temperature of the semi-cylindrical heat-sensitive magnetic body 5, that is, the operating temperature, the heat-sensitive magnetic body 5 exhibits a ferromagnetic state. However, the leakage magnetic flux (2) passes through the lead pieces 2a, 2b, so that the lead contacts are closed (FIG. 3a).

On the other hand, when the ambient temperature exceeds the Curie temperature of the heat-sensitive magnetic body 5, the heat-sensitive magnetic body 5 loses its magnetism and enters a paramagnetic state, so that the leakage magnetic flux (2) also passes through the lead pieces 2a, 2b.

However, the leakage magnetic fluxes ■ and ■ are caused by the lead pieces 2a and 2b, respectively.
Since the directions passing through the inside are reversed, the lead pieces 2a,
The amount of magnetic flux passing through 2b becomes zero and the reed contact is opened (FIG. 3b).

Next, FIG. 5 shows changes in the amount of magnetic flux in the lead piece with respect to temperature.

The diagonal lines in the figure indicate the range in which the lead contacts are opened, which is indicated by the above-mentioned operating temperature TA.

Now, when the position of the semi-cylindrical heat-sensitive magnetic body 5 in the rotational direction with respect to the cylindrical permanent magnets 4a and 4b changes from the diagonal line position shown in FIG. 4a to the diagonal line position shown in FIG. As a result of the decrease in the amount of magnetic flux, the total amount of magnetic flux passing through the lead piece changes as shown by the broken line in FIG.

Therefore, the operating temperature decreases from TA to TA', making it possible to finely adjust the temperature.

According to this invention, as described above, a simple method using two cylindrical permanent magnets, each magnetized with two poles in opposing surfaces, and a semi-cylindrical heat-sensitive magnetic body disposed between them. Although it has a simple structure, it is possible to adjust the operating temperature by changing the relative rotation angle between them, allowing for extremely high precision and great effects.

The heat-sensitive reed switch mentioned above uses a normally closed type switch, but if a normally open type is used, the reed contact opens on the low temperature side and closes on the high temperature side, and the opening/closing operation is reversed from the above. It is obvious that a heat-sensitive reed switch can be obtained.

[Brief explanation of the drawing]

Figure 1 is a longitudinal sectional front view showing a conventional temperature-sensitive reed switch.
Fig. 2 is an exploded perspective view showing one embodiment of the heat-sensitive reed switch of this invention, Figs. 3 a and b are explanatory diagrams showing the basic operation of the heat-sensitive reed switch of this invention, and Figs. 4 a and b.
is an explanatory diagram showing the positional relationship in the rotational direction between the cylindrical permanent magnet and the semi-cylindrical heat-sensitive magnetic material that constitute this devised heat-sensitive reed switch, and Fig. 5 shows the change in the amount of magnetic flux in the reed piece with respect to temperature in this devised heat-sensitive reed switch. FIG. In the figure 1... Reed switch, 2a, 2b...
...Reed piece, 3...Glass tube, 4a, 4b
... Cylindrical permanent magnet, 5 ... Semi-cylindrical thermosensitive magnetic material.

Claims (1)

[Scope of utility model registration request] A reed switch formed by enclosing two reed pieces in a cylinder, and two bipolar magnetized pieces surrounding the outer periphery of the reed switch and arranged so that their opposing surfaces have different magnetic poles facing each other. A heat-sensitive reed switch comprising: a cylindrical permanent magnet; and a semi-cylindrical heat-sensitive magnetic body disposed between the cylindrical permanent magnets.