JPS6025860Y2 - solenoid - Google Patents

Description

[Detailed description of the invention] This invention relates to a solenoid that prevents the holding force from decreasing in a high temperature atmosphere.

Recently, solenoids have been increasingly used in a wide variety of applications, but they are sometimes used in extremely high-temperature environments due to the heat generated by excitation coils.

However, it is generally known that the holding force of a solenoid changes depending on the ambient temperature. For example, if the resistance of the exciting coil is R at a temperature of 20°C, and the ambient temperature rises to 100°C, the resistance of the exciting coil will increase to 1. 3R also increases, the excitation current decreases accordingly, and the ampering pattern, that is, the holding force, decreases significantly.

For this reason, when such a solenoid is used in a high-temperature atmosphere, the holding force decreases depending on the ambient temperature, which may cause the operating plunger to return incorrectly. This caused undesirable malfunctions.

This invention was devised to eliminate the above-mentioned drawbacks, and the purpose is to provide a Tsuremade that uses a temperature-sensitive magnetic element to prevent a decrease in holding force in a high-temperature atmosphere and that can be expected to operate stably.

An embodiment of this invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a cylindrical bobbin around which an excitation coil 2 is wound.A fixed iron core 3 and a plunger 4 are provided in a hollow portion of the bobbin 1 so as to be able to move toward and away from the bobbin.

A temperature-sensitive magnetic element 5 is interposed around the contact surface between the fixed core 3 and the plunger 4.

In this case, in the illustrated example, the plunger 4 side end of the fixed iron core 3 is formed into a small diameter part 31, and a cylindrical temperature-sensitive magnetic element 5, for example, is provided protrudingly around this small diameter part 31, and the plunger 4
Also, the side end of the fixed core 3 is formed into a small diameter part 41.
is inserted into the hollow part of the temperature-sensitive magnetic element 5 so as to come into contact with the fixed iron core 3.

Here, the temperature-sensitive magnetic element 5 is a magnetic material at room temperature and becomes a non-magnetic material at a temperature higher than a predetermined temperature, that is, higher than the Curie temperature.
i-series magnetic shunt steel, Mn-Cu ferrite, N1-CLI
(27) Alloys etc. are used.

In addition, 6 in the drawing is a cover.

Next, its effect will be explained.

Now, when the excitation coil 2 is energized from a state where the fixed iron core 3 and the plunger 4 are separated as shown in FIG. Magnetic flux φ1 transmitted from iron core 3 to plunger 4 and magnetic flux φ transmitted to plunger 4 via temperature-sensitive magnetic element 5
2, the plunger 4 is attracted in the direction of the fixed iron core 3 and moved to the left in the figure until it is attracted to the fixed iron core 3.

In this case, since the magnetic flux φ2 can be applied to the plunger 4 via the temperature-sensitive magnetic element 5, a large operating force can be obtained.

Further, in the state shown in FIG. 2 in which the plunger 4 is attracted to the fixed iron core 3, its operation is maintained by the magnetic fluxes φ1 and φ2.

From this state, the ambient temperature rises due to heat generated by the excitation coil 2, etc., and when this temperature reaches the Curie temperature or higher of the temperature-sensitive magnetic element 5, the element 5 changes into a non-magnetic material.

Then, until now, the plunger 4 is
The magnetic flux φ2 that had been transmitted to the plunger 4 is removed, and as shown in FIG.
It becomes concentrated and transmitted.

Therefore, this concentration of magnetic flux can compensate for the decrease in holding force due to the rise in ambient temperature, thereby preventing the holding force from decreasing during the operating state, and stable operation can be expected.

It should be noted that this invention is not limited to the above-mentioned embodiments, but can be implemented with appropriate modifications without changing the gist.

For example, as shown in FIG. 3, the fixed core 3 and the plunger 4 each have tapered protrusions 32 and 42 on opposing surfaces that come into contact with and separate from each other.
may be formed.

In addition, as shown in FIG.
3 may be provided.

Further, as shown in FIG. 5, the plunger 4 may be provided with a tapered protrusion 44, and the temperature-sensitive magnetic element 5 may be provided with a tapered portion 51 corresponding thereto.

Furthermore, in the above description, the temperature-sensitive magnetic element 5 is consistently attached to the fixed iron core 3.
Although it is provided on the side, it can also be provided on the plunger 4 side.

As described above, according to this invention, by using a temperature-sensitive magnetic element, it is possible to prevent a decrease in holding force in a high-temperature atmosphere, and it is possible to provide a solenoid that can be expected to operate stably.

[Brief explanation of drawings]

Figure 1 is a vertical sectional view showing an embodiment of this invention, Figure 2 a
, by c are schematic configuration diagrams for explaining the operation of the same embodiment, and FIGS. 3 to 5 are schematic configuration diagrams showing the main parts of other embodiments of this invention, respectively. 1...Bobbin, 2...Excitation coil, 3
...Fixed iron core, 4...Plunger, 5
...Temperature-sensitive magnetic element.

Claims (2)

[Scope of utility model registration request] (1) A cylindrical bobbin wound with an excitation coil, a fixed core and a plunger installed in the hollow part of the bobbin so as to be able to approach and separate, and a contact between the fixed core and the plunger. Tsuremade is characterized by being equipped with a temperature-sensitive magnetic element. (2) The slide/id as claimed in claim 1, wherein the temperature-sensitive magnetic element is attached to the fixed core side.