JPS628112Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a temperature-sensitive switch that combines a magnetic assembly consisting of a permanent magnet and a temperature-sensitive magnetic material, and a magnetic sensing element.

Conventionally, this type of temperature-sensitive switch has often used a reed switch as the magnetic sensing element, but since the reed switch is a contact point, it has the disadvantage that it is inferior to a non-contact semiconductor element in terms of reliability. Ta.

The purpose of the present invention is to provide a non-contact temperature-sensitive switch.

According to the present invention, on the outside of a non-magnetic casing made of an opaque material, a bar-shaped magnet and a Curie point corresponding to the detected temperature are arranged so as to short-circuit the magnetic flux from the bar-shaped magnet at a temperature lower than the detected temperature. a magnetic assembly made of a warm magnetic material;
a ferromagnetic fixed piece having a Curie point higher than the detection temperature fixed near one longitudinal end of the magnetic assembly; one end fixed to the other longitudinal end of the magnetic assembly; the free end is arranged so as to face the ferromagnetic fixed piece at a distance,
and a magnetic sensing element comprising a flexible ferromagnetic plate-like body having a Curie point higher than the detection temperature, the free end side of which is provided with a reflective surface, and a light emitting element and a light receiving element arranged opposite to the reflective surface. A temperature-sensitive switch is obtained which is characterized by having the following characteristics.

A detailed explanation will be given below with reference to the drawings.

FIG. 1 is a front view showing the structure of a conventional temperature-sensitive switch, in which 1 is a reed switch, 2 and 2 are permanent magnets, and 3 is a temperature-sensitive magnetic body.

The temperature-sensitive switch with the structure shown in Figure 1 is small,
This is an inexpensive switch that takes advantage of the features of the reed switch 1, such as high-speed operation and unaffected by the atmosphere, and the reversible phenomenon in which the temperature-sensitive magnetic material 3 suddenly becomes ferromagnetic or paramagnetic after reaching the Kyrie point. It is used for this purpose. The reed switch 1 has contact portions plated with rhodium and is filled with a special gas to maintain a high level of service life and reliability. However, since the reed switch 1 is a contact point, it is inferior to a non-contact semiconductor element in terms of reliability.

FIG. 2 is a front sectional view showing the configuration of an embodiment of the present invention. 4 is a non-magnetic and opaque casing for housing the magnetic sensing element. A ferromagnetic fixing piece 5 is fixed to the end of the upper inner wall of the housing 4. 6 is a flexible elongated ferromagnetic plate,
The main surface faces the upper wall of the casing 4, and one end faces the fixed piece 5 with a space therebetween,
The other end is fixed to the upper part of the side wall on the far side from the fixed piece 5. Both the fixed piece 5 and the plate-shaped body 6 have a Curie point that is sufficiently higher than the detected temperature. Reference numeral 7 denotes a reflective surface, such as a reflective tape, which is attached to the main surface of the plate-shaped body 6 on the opposite side to the fixing piece 5. 8 is a light emitting element, and 9 is a light receiving element, which are arranged opposite to the reflective tape 7. Reference numeral 10 denotes a U-shaped temperature-sensitive magnetic material made of, for example, ferrite and having a required Curie point. 11
is a bar-shaped magnet and is installed inside the recess of the temperature-sensitive magnetic body 10. The temperature-sensitive magnetic body 10 and the magnet 11 are arranged so that the magnetic poles of the magnet 11 are oriented in the longitudinal direction of the plate-like body 6 on the outer surface (the upper surface in the figure) of the casing 4 near the opposing portion of the fixed piece 5 and the plate-like body 6. attached parallel to.

FIG. 2 shows the state when the temperature of the temperature-sensitive magnetic body 10 is below the Curie point. The magnetic flux from the magnet 11 passes through the temperature-sensitive magnetic material 10 exhibiting ferromagnetism and does not flow to the opposing portion of the fixed piece 5 and the plate-like member 6, so the free end of the plate-like member 6 is in a state separated from the fixed member 5. Since the light emitted from the light-emitting element 8 and reflected by the reflective surface 7 does not enter the light-receiving element 9, there is no output current in the light-receiving element 9.

On the other hand, when the ambient temperature rises and the temperature of the temperature-sensitive magnetic material 10 reaches or exceeds the Curie point, the temperature-sensitive magnetic material 10 exhibits paramagnetism, so it is in a state where it does not exist magnetically, as shown by the broken line in FIG. As a result, the magnetic flux from the magnet 11 flows to the opposing part of the fixed piece 5 and the plate-like body 6, and a magnetic attraction force is generated between the fixed piece 5 and the plate-like body 6, so that the free end of the plate-like body 6 moves towards the fixed piece 5. The plate-shaped body 6 is bent. As shown in the figure, the direction of the reflective surface 7 changes and the light from the light emitting element 8 is reflected by the reflective surface 7 and then enters the light receiving element 9, so that an output current is generated in the light receiving element 9. Therefore, depending on the presence or absence of the output from the light receiving element 9, it is possible to detect whether the ambient temperature is below or above the Curie point.

Fixed piece 5, plate-shaped body 6, light emitting element 8, light receiving element 9
It is a non-contact temperature-sensitive switch that is not affected by the atmosphere because it is housed in the housing 4, and the fixed piece 5
Since the plate-like body 6 is not energized, there is no need to perform any special treatment on the facing portion, and there is no need to fill the housing 4 with a special gas, so it can be manufactured at low cost. The interior of the housing 4 is treated to prevent reflection from surfaces other than the reflective surface 7.

The light receiving element 9 is located at position A indicated by the chain line in FIG.
By arranging the light receiving element 9 during normal (low temperature)
It can be used as a temperature-sensitive switch that has an output current at high temperatures and no output current at high temperatures.

FIG. 4 shows an application example of the temperature-sensitive switch according to the present invention, in which a resistance heating element 12 is attached to the temperature-sensitive magnetic body 10. When the heating element 12 is energized, the power consumption and the temperature of the temperature-sensitive magnetic body 10 are reduced. By checking the relationship with the time taken for the temperature to reach the Curie point, it is possible to change the power consumption and use it as a timer.Also, by connecting the heating element 12 to a circuit that requires overcurrent detection, the light receiving element 9 Overcurrent can be detected by connecting an alarm to.

As is clear from the above description, the present invention has the effect of providing a non-contact and inexpensive temperature-sensitive switch.

[Brief explanation of the drawing]

Fig. 1 is a front view showing the structure of a conventional temperature-sensitive switch, Fig. 2 is a front sectional view showing the structure of an embodiment of the temperature-sensitive switch according to the present invention, and Fig. 3 is a structure similar to Fig. 2. The figure shows a front cross-sectional view when the temperature is above the Curie point of the temperature-sensitive magnetic material, and FIG. 4 is a front cross-sectional view showing an example of application of the present invention. Explanation of symbols: 1 is a reed switch, 2 is a permanent magnet, 3 is a temperature-sensitive magnetic material, 4 is an opaque non-magnetic casing,
5 is a ferromagnetic fixed piece, 6 is a flexible ferromagnetic plate, 7
is a reflective tape, 8 is a light emitting element, 9 is a light receiving element, 1
0 represents a temperature-sensitive magnetic material, 11 represents a permanent magnet, and 12 represents a heating element.

Claims (1)

[Scope of utility model registration request] A bar-shaped magnet and a temperature-sensitive magnetic body having a Curie point corresponding to the detection temperature arranged so as to short-circuit the magnetic flux from the bar-shaped magnet at a temperature below the detection temperature are disposed on the outside of a non-magnetic casing made of an opaque material. a magnetic assembly; a ferromagnetic fixed piece having a Curie point higher than the detection temperature fixed within the non-magnetic housing near one longitudinal end of the magnetic assembly; one end of which is fixed to the magnetic assembly; A Curly wire whose temperature is higher than the detection temperature is fixed to the other end in the longitudinal direction, and the other free end is arranged to face the ferromagnetic fixed piece at a distance, and a reflecting surface is provided on the free end side. 1. A temperature-sensitive switch comprising: a flexible ferromagnetic plate having dots; and a magnetic sensing element comprising a light-emitting element and a light-receiving element arranged opposite to the reflective surface.