JPS6116587Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a band-operated temperature switch structure that combines a reed switch, a permanent magnet, and a temperature-sensitive magnetic material so that the reed switch contact closes only when the temperature is within a specific range. Regarding.

There are several types of band-operated temperature switches of this type. A typical format is shown in Figure 1.
Referring to FIG. 1, on the outer periphery of the reed switch 1, there are first and second permanent magnets magnetized in the same direction in the axial direction of the reed switch 1, corresponding to the reed pieces 2 and 3, respectively. 5, 6, and a temperature-sensitive magnetic body 7 having a relatively high Curie point between these permanent magnets 5, 6. Further, a temperature-sensitive magnetic body 8 having a relatively low Curie point is disposed outside the permanent magnets 5, 6 and the temperature-sensitive magnetic body. When the ambient temperature determined by the temperature switch 4 is lower than the low-temperature operation, that is, lower than the Curie point of the temperature-sensitive magnetic body 8, both the temperature-sensitive magnetic bodies 7 and 8 are ferromagnetic, so the magnetic flux from the permanent magnets 5 and 6 is short-circuited. The reed switch 1 is in an open state, with almost no flow flowing into the reed pieces 2 and 3, and the contact 4 of the reed switch 1 is in an open state. When the temperature rises and reaches the Curie point (low temperature side operating temperature) of the temperature-sensitive magnetic body 8, the temperature-sensitive magnetic body 8 exhibits paramagnetism, and the temperature-sensitive magnetic body 7 exhibits ferromagnetism, so that the permanent magnets 5, 6 The magnetic flux from the lead pieces 2 and 3
The contact 4 is closed. When the temperature further rises and reaches the Curie point (high temperature side operating temperature) of the temperature-sensitive magnetic body 7, the temperature-sensitive magnetic body 7 also becomes paramagnetic, so the magnetic flux from the permanent magnets 5 and 6 is transferred to the reed switch 1. There is no flow to the contact portion, and the contact point 4 is opened. If the temperature drops, the contact 4 performs the opposite operation at a return temperature slightly lower than the operating temperature.

However, the temperature switch shown in FIG. 1 has the following drawbacks. That is, especially at low temperatures,
The magnets emitted from the permanent magnets 5 and 6 cannot be focused on the temperature-sensitive magnetic body 8, and the reed pieces 2 and 3 of the reed switch 1
Therefore, the optimum conditions for low-temperature characteristics and the optimum conditions for high-temperature characteristics do not match, and in order to operate at both low and high temperatures, it is necessary to , it must be balanced and is unstable. In addition, individual parts have variations, so at low temperatures,
The temperature characteristics at high temperatures vary greatly.

It is an object of the present invention to provide a band-operated temperature switch that has improved low-temperature characteristics, exhibits stable band operation even when using components with suitable variations, and has temperature characteristics with small variations.

FIG. 2 shows a first embodiment of the invention. In this first embodiment, the permanent magnets 5 and 6 of the temperature switch shown in FIG.
Yokes 9 and 10 made of a magnetic material having a higher Curie point are attached. FIG. 3 shows a second embodiment of the invention. In this second embodiment, the temperature-sensitive magnetic body 8 is longer than the alloy length of the permanent magnets 5, 6 and the temperature-sensitive magnetic body 7, and protrudes substantially equally from both ends of the permanent magnets 5, 6.
Yokes 9 and 10 having a higher Curie point than the temperature-sensitive magnetic body 8 are provided in close contact with both end surfaces of the permanent magnets 5 and 6 and inside the protrusion of the temperature-sensitive magnetic body 8. FIG. 4 shows an embodiment in which the temperature-sensitive magnetic body 7 is extended to the outer surface of the outer temperature-sensitive magnetic body 8 in the embodiment shown in FIG.

The operation of the band-operated temperature switch of the present invention will be explained using the third embodiment shown in FIG. FIG. 4 shows a state where the ambient temperature is low, that is, below the Curie point of the temperature-sensitive magnetic body 8. At this temperature, both the temperature-sensitive magnetic bodies 7 and 8 exhibit ferromagnetism, so the magnetic flux from the permanent magnets 5 and 6 becomes a magnetic flux φ ₁ through which the temperature-sensitive magnetic body 8 flows, as shown by the broken line in the figure. At this time, the yokes 9 and 10 form a magnetic path for the magnetic flux flowing to the temperature-sensitive magnetic body 8, so the leakage magnetic flux _φ2 flowing to the lead pieces 2 and 3 is sufficiently smaller than when the yokes 9 and 10 are not provided. , so the contact never closes.

FIG. 5 shows a case where the temperature rises and reaches the Curie point (low temperature side operating temperature) of the temperature sensitive magnetic body 8. At this temperature, only the temperature-sensitive magnetic body 8 exhibits paramagnetism, so the magnetic flux φ ₁ decreases and the magnetic flux φ ₂ flowing through the reed pieces 2 and 3 increases, thereby closing the contact 4. FIG. 6 shows a case where the temperature further rises to exceed the Curie point (high-temperature side operating point) of the temperature-sensitive magnetic body 7. At this temperature, both the temperature-sensitive magnetic bodies 7 and 8 and the yokes 9 and 10 exhibit paramagnetic properties, so leakage magnetic flux φ ₃ flows into the contact portion from between the permanent magnets 5 and 6. This leakage magnetic flux φ ₃ cancels the magnetic flux φ ₂ flowing through the lead pieces 2 and 3 at the contact portion. Therefore, the contact 4 is separated by the elasticity of the lead pieces 2 and 3. It will be understood from this that the specific position of the permanent magnet 56 in the axial direction of the reed switch 1 is determined. That is, the permanent magnet 5,
6 is provided at a position where the contacts of the reed switch are opened and closed by these alone.

The yokes 9 and 10 are usually made of a ferromagnetic material such as a soft magnetic material such as temperature-sensitive ferrite, but may also be made of a ferromagnetic material of a hard magnetic material such as soft iron.

In the above, an embodiment in which the permanent magnets and the temperature-sensitive magnetic material are arranged only on one side of the outer periphery of the reed switch has been described, but for example, as shown in FIG. , 8 and yokes 9, 10 can also be used to assemble a temperature switch.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a conventional band-operated temperature switch, FIG. 2 is a cross-sectional view of a first embodiment of the band-operated temperature switch according to the present invention, and FIG. 3 is a cross-sectional view of the second embodiment. 4 to 6 are sectional explanatory views of the third embodiment, and FIG. 7 is a sectional view of a modification of the third embodiment. 1...Reed switch, 2, 3...Reed piece,
4...Contact, 5,6...Permanent magnet, 7...Temperature-sensitive magnetic material having a relatively high Kyrie point, 8...Temperature-sensitive magnetic material having a relatively low Kyrie point, 9,10
……yoke.

Claims (1)

[Scope of utility model registration request] A reed switch has a pair of reed pieces with one end facing each other and the other end extending in opposite directions, and a reed switch arranged on the outer periphery of the reed switch at a position corresponding to each of the pair of lead pieces. , first and second permanent magnets both magnetized in the axial direction of the reed switch and in the same direction;
a first temperature-sensitive magnetic body having a relatively high Curie point arranged between the first and second permanent magnets;
A band-operated temperature switch comprising a second temperature-sensitive magnetic material having a relatively low Curie point disposed at least outside the first and second permanent magnets, Consisting of a magnetic material having a Curie point lower than the first temperature-sensitive magnetic material and higher than the second temperature-sensitive magnetic material, which covers the pole end surface and is in contact with the end surface or inside of the second temperature-sensitive magnetic material. A band-operated temperature switch featuring a yoke.