JPS5910010B2 - Thermal lead switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal reed switch whose contacts are opened and closed by an external magnetic field, and particularly to a thermal reed switch using a reed switch sealed with mercury.

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 and R2Co1 (R represents a rare earth metal), are known as high-performance permanent magnet materials.

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 NdCo5jY1-XNdxCo5 (X=
0.75, X=0.5o, X=0.25
) and PrCo5 data are shown.

In the figure, the horizontal axis direction is temperature (''.

K), and the vertical axis direction represents the narrow angle φ) between the C-axis direction of the magnetic material and the easy magnetization axis direction.

According to the figure, β changes rapidly for NdCo from around 250°K, but it changes gradually for Yo5 Ndo5 Co5, etc.

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

Figure 2 shows the case of RCo5, and Figure 3 shows the case of R2Co17.
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 shown above, among alloys containing rare earth metals, there are some whose axis of easy magnetization changes depending on temperature, but 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, and combinations of thermocouples and relays have been conventionally used as temperature-sensitive switches, but all of them have the disadvantage of slow response speed to ambient temperature. there were.

The present invention has been made in view of the above-mentioned drawbacks, and the present invention has been developed to reduce the external magnetic field that controls the opening and closing of a reed switch containing mercury.
This paper proposes a new thermal reed switch made of a permanent magnet and a spin-rearranged ferromagnetic material (SRM) whose magnetization axis direction easily changes depending on temperature.

Briefly stated, the present invention relates to a mercury-filled reed switch of a type in which opening and closing of contacts are controlled by applying a magnetic field from the outside, in which means for applying the magnetic field includes at least one permanent magnet and a magnetic path of the magnet. It is characterized by comprising a spin-rearranged ferromagnetic material whose magnetization axis direction easily changes depending on the temperature at which it is placed.

More specifically, (1) a fixed contact piece and a movable contact piece are also arranged inside a glass tube, and a predetermined amount of mercury is sealed in the tube wall of a mercury-filled reed switch that controls the opening and closing of the contacts by applying a magnetic field from the outside. Along the line, a permanent magnet, a soft magnetic material at both ends of the magnet, and a spin-rearranged ferromagnetic material in contact with the magnet are set such that the axis of easy magnetization is parallel to or perpendicular to the magnetic path of the magnet. Thermal reed switch features.

(2) A fixed contact piece and a movable contact piece are arranged inside a glass tube, and a predetermined amount of mercury is sealed in the tube wall of the movable contact side of a reed switch that controls the opening and closing of the contacts by applying a magnetic field from the outside. The external magnetic field of a laminated structure of a spin-rearranged ferromagnetic material and a permanent magnet is parallel to the fixed armature and the movable armature, and the easy axis of magnetization of the spin-rearranged ferromagnetic material is parallel to both the armatures. A thermal reed switch characterized by being arranged parallel or perpendicular.

(3) A permanent magnet is placed along the tube wall of a mercury-filled reed switch, which has a fixed contact piece and a movable contact piece placed inside a glass tube, and controls the opening and closing of the contacts by applying a magnetic field from the outside that contains a predetermined amount of mercury. and a spin-rearranged ferromagnetic material whose axis of easy magnetization is set parallel or perpendicular to the magnetic path of the magnet, which are arranged in series.

(4) The thermal reed switch according to item 3, characterized in that a soft magnetic material is arranged adjacent to the spin-rearranged ferromagnetic material in series.

It provides:

The thermal reed switch according to the present invention will be explained in detail below with reference to the drawings. Since this reed switch is of the type that encapsulates mercury, it can be installed so that the length of the glass tube is almost vertical and the contacts are upward. desirable.

FIG. 4 shows an embodiment of the thermal reed switch according to the present invention, in which a is a side sectional view showing a schematic configuration, and b is an SRM.
1 is a plan view showing the direction of the magnetization axis, 1 is a permanent magnet, 2 is a soft magnetic material disposed in the magnetic path of permanent magnet 1, 3 is an SRM, and 3 is a permanent magnet.
3a and 3b are magnetization axis directions, and 4 is a reed switch in which mercury 5 is sealed.

In the thermal reed switch having such a configuration, the reed switch 4 is fixed in a glass tube, and has a contact piece 4a and a movable contact piece 4b that retains a recovery force, and is used to store a predetermined amount of mercury 5 and other than the mercury 5. For example, hydrogen gas (
H2), and is processed so that mercury always adheres to the surface where the movable contact piece 4b contacts the fixed contact piece 4a due to surface tension.

A permanent magnet 1 is placed along the tube wall of this reed switch 4.
Then, an external magnetic field is formed by arranging a soft magnetic material 2 at both ends of the magnet 1 to prevent leakage of magnetic flux and an SRM 3 in contact with the permanent magnet 1, and the external magnetic field is parallel to each contact piece 4a, 4b. Furthermore, the fixed contact piece 4a is connected to the external magnetic field and the movable contact piece 4b.
It is attached by sandwiching it between the two.

Thus, by setting the magnetization axis direction of the SRM 3 that forms the external magnetic field to a direction 3a parallel to the magnetic path of the permanent magnet 1 or a direction 3b perpendicular to the magnetic path of the permanent magnet 1 as shown in FIG. Becomes open or closed,
As the ambient temperature rises, the direction of the magnetization axis changes, resulting in a closed or open state, which is opposite to that at room temperature.

That is, when the magnetization axis direction is 3a at room temperature, a magnetic path as indicated by the dotted line A is formed, so that the contact pieces 4a and 4b of the reed switch 4 are in an open state because no magnetic field acts on them.

When the ambient temperature of the reed switch 4 rises in this state, the direction of the magnetization axis changes, so the magnetic path A disappears, and the magnetic path changes from the permanent magnet to the soft magnetic material 2 to form the movable contact piece 4b. Therefore, the reed switch 4 is in the closed state.

Note that the soft magnetic material 2 is a magnetic conductive material that prevents magnetic flux from leaking from the permanent magnet 1.

FIGS. 5 to γ show other embodiments of the thermal reed switch according to the present invention, and throughout all the embodiments, the same parts are designated by the same reference numerals.

FIG. 5 shows a pipe wall on the movable contact piece 4a side of the reed switch 4.
The external magnetic field has a structure in which the SRM 3 and the permanent magnet 1 are stacked, and the external magnetic field and the movable contact piece 4b sandwich the fixed contact piece 4a, and the external magnetic field is arranged in parallel with each of the contact pieces 4a and 4b. It is something.

Therefore, when the magnetization axis direction of the SRM 3 is 3a, it is in an open state, and when the magnetization axis direction is 3b, it is in a closed state.

Figure 6 shows a configuration in which permanent magnet 1 and SRM 3 are arranged in series for the external magnetic field.The configuration other than this external magnetic field is the same as described above, but in the case of this external magnetic field, if the magnetization axis direction is 3a, it will be closed. In the case of 3b, it becomes an open state.

FIG. 7 shows an external magnetic field obtained by arranging the soft magnetic material 2 adjacent to the SRM 3 of the external magnetic field obtained by connecting the permanent magnet 1 and the SRM 3 in series in FIG. 6, and shows the structure and operation of the thermal reed switch other than this external magnetic field is no different from the previous figure.

In addition, the external magnetic field in this example is the permanent magnet 1 and the SRM 3.
Although the combination of the permanent magnet 1, the SRM 3, and the soft magnetic material 2 has been described in detail, the configuration of this external magnetic field may be any configuration depending on the purpose; What about the composition and the inclination of the magnetization axis with respect to the magnetic path? It can be changed depending on the application.

As described above, according to the thermal reed switch according to the present invention, the direction of the magnetization axis of the SRM at ambient temperature can be easily changed, so that the constant speed with respect to temperature changes can be shortened.

This improves the reliability of the switch, and since mercury is always attached to the movable contact piece, it can be expected to extend the life of the switch, making it extremely effective when applied to temperature control of various electronic devices. .

[Brief explanation of drawings]

Figure 1 shows N d Co 5 + Y1 − x N
d x Co 5 and P r Co 5. Figure 2 shows the temperature change in the easy magnetization axis direction of alloy RCo5 containing rare earth metals. Figure 3 shows the temperature change in the easy magnetization axis direction of alloy RCo5 containing rare earth metals. Temperature change in the easy magnetization axis direction of R2Co1, FIG. 4 shows an embodiment of the thermal reed switch according to the present invention, a is a side sectional view showing the schematic configuration, and b is a front view showing the magnetization axis direction of RRM. , FIGS. 5 to 7 show other embodiments of the thermal reed switch according to the present invention. 1: Permanent magnet, 2: Soft magnetic material, 3: SRM, 3a, 3
b: Easy magnetization axial direction, 4: Reed switch, 4a two fixed contact pieces, 4b = movable contact piece, 5: mercury.

Claims (1)

[Claims] 1. A mercury-filled reed switch in which a fixed contact piece and a movable contact piece are arranged in a glass tube, and a predetermined amount of mercury is sealed in the switch to control the opening and closing of the contacts by applying a magnetic field from the outside, and means for applying the magnetic field. is a spin reproducing alloy containing at least one permanent magnet and a rare earth metal whose easy axis of magnetization is set in a magnetic path of the magnet so that its axis of easy magnetization is parallel or perpendicular to the magnetic path. A thermal reed switch comprising an array type ferromagnetic material.