JPS6364230A - Temperature detecting element - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a temperature detection element used for temperature detection in rice cookers, air conditioners, etc., or cooling water temperature detection in automobiles, etc.

<Prior Art> FIG. 18 shows an example of a conventional temperature detection element using a combination of a temperature-sensitive magnetic material, a permanent magnet, and a reed switch. In the figure, permanent magnets 2 having the same cross-sectional shape are arranged on both sides of a cylindrical temperature-sensitive magnetic body 1, and a K IJ-do switch 3 is inserted into the central hole of the combined part. The magnetic flux density B vs. temperature T characteristics of the temperature-sensitive magnetic material 1 are shown in FIGS. 19 and 2.
In Figure 0: Normally closed type and normally open type temperature sensing elements having the characteristic that the magnetic flux density B suddenly decreases at a sea urchin temperature Tc are obtained. The temperature-sensitive magnetic material 1 is made of Mn--Zn ferrite, and its Curie temperature Tc can be arbitrarily determined over a wide range from -40 DEG C. to +200 DEG C. depending on the material composition. The ambient temperature is Tc
In the following, the magnetic flux of permanent magnet 2 is 1.7? The magnetic flux outside the permanent magnet passes through the thermal property 1 and flows into the reed piece of the reed switch 3, turning on the contact.

On the other hand, when the temperature rises and reaches the temperature Tc, the temperature-sensitive magnetic body 1 becomes non-magnetic, and the magnetic flux that has been flowing through the temperature-sensitive magnetic body 1 leaks and flows into the reed switch 3 side as leakage magnetic flux.
Moreover, the magnetic flux flowing into the series reed switch 3 from both outside sides of the permanent magnet 2 cancels out, and the magnetic flux applied to the reed switch 3 becomes less than the open magnetic flux density of the reed switch 3.
The contact of the reed switch 3 is turned off, and it is detected that the temperature has reached Tc. This temperature detection element is a fixed point operation type temperature detection element that can detect the operating temperature at the key temperature Tc of the temperature sensitive magnetic body 1, and is low in price with little aging.

<Problems to be Solved by the Invention> However, temperature detection elements generally detect temperature at one point, and are not capable of continuous temperature detection, such as with a thermistor. Therefore, fixed-point temperature detection and continuous temperature detection are possible, as in the conventional example of a composite temperature detection element in which a magnetically operated fixed-point temperature detection element 10 and a thermistor element 11 are combined on the same substrate 12 as shown in FIG. .

However, although this type of temperature sensing element is suitable for a wide range of applications, it has the disadvantage of being expensive because it requires two elements.

Means for Solving the Problems> The present invention eliminates the above drawbacks of the conventional method and provides a lead piece 31 on the outside.
．． A cylindrical temperature-sensitive magnetic body 1 having two terminals 6 and 7 externally drawn out from electrodes 4 and 5 provided on both sides or at two locations on the outer periphery of a reed switch 3 provided with a reed switch 3. In the temperature sensing element in which a cylindrical permanent magnet 2 is provided in contact with both sides of the lead piece 31, 32 and the terminals 6, 7.
or pull out the lead pieces 31 independently.
32 and either one of the terminals 6, 7 are electrically connected, or each of the lead pieces 31, 32 and each of the terminals 6, 7 are electrically connected.

<Effect> Electrodes 4.5 are provided on the temperature-sensitive magnetic material 1 and pulled out.

By changing the connections of the reed pieces 31 and 32 of the reed switch 3, the temperature detection element can perform both one-point temperature detection and continuous temperature detection functions in response to temperature changes.

<Example> An example of the temperature detection element of the present invention will be described with reference to an external perspective view in FIG. 1 and an exploded external perspective view in FIG.

The temperature-sensitive magnetic body 1 of the present invention has a cylindrical shape, and electrodes 4. and 5 are provided. On both sides of this temperature-sensitive magnetic body 1, cylindrical permanent magnets 2 are magnetized in the axial direction and are combined so that different poles oppose each other. A reed switch 3 is inserted into the hole.

Lead wires are connected to a part of the outer periphery of the electrodes 4.5 of the temperature-sensitive magnetic material 1 and are brought out as terminals 6, 7 to the outside. The temperature-sensitive magnetic material 1 is made of a 1n-Zn ferrite material whose magnetic flux density is B.
The temperature vs. T characteristic is shown in Figure 3.
The magnetic flux density B suddenly decreases at
also has semiconductor properties.

The resistance R vs. temperature T and the π dimension shown in Figure 4 of the housing? The resistance value R tends to decrease exponentially with respect to the temperature T. Its resistance value R is within 5Ω to 100Ω at room temperature of 24°C, and its resistance change rate with respect to temperature change is around -4 to -5 coefficient, and has almost the same performance as conventional thermistors. However, it can be used as an element for continuous temperature detection.

From the magnetic circuit of the combination of the temperature-sensitive magnetic body 1 and the permanent magnet 2, as shown in Fig. 5, below the key temperature Tc, the magnetic flux φ from the permanent magnet 2 passes through the temperature-sensitive magnetic body 1 and becomes the magnetic flux φ1, and becomes a permanent magnet. Since the magnetic flux flows from the outside of the magnet 2 into the reed switch 3 and exceeds the magnetic flux density, the reed switch contact is turned on.

When the temperature rises and reaches the temperature Tc, the magnetic flux that has been passing through the temperature-sensitive magnetic body 1 leaks and flows into the reed switch contact as magnetic flux, as shown in Figure 6, and the magnetic flux has a direction opposite to that of the previous magnetic flux. Therefore, the phases cancel each other out, and the magnetic flux density becomes lower than the open magnetic flux density of the reed switch 3, so that the reed switch 3 is turned off.

Therefore, the operation of the conventional normally-closed temperature switch at the detected temperature Tc shown in FIG. 19 will be described. Normally, the contact strength of the reed switch 3 is IOW ~ 50W, and it is possible to directly connect a relay or heater.

On the other hand, the lead wires 6 and 7 detect the resistance value itself of the temperature-sensitive magnetic body 1, and its characteristics are shown in FIG.

Continuous temperature detection is possible without depending on the Curie temperature Tc.

Therefore, in the temperature switch of the present invention shown in FIG. 1, it is possible to detect a fixed point temperature from the lead pieces 31 and 32 with exactly the same component configuration. A composite temperature detection element capable of detecting temperature can be realized.

FIG. 7 shows another embodiment of the present invention, in which electrodes 4 and 5 of the temperature-sensitive magnetic body 1 are provided at two arbitrary locations on the cylindrical side surface. Lead wires are taken out from the electrodes 4 and 5 and connected to a terminal 6.7, through which the resistance value of the temperature-sensitive magnetic body 1 is detected. in this case.

Since the electrodes 4 and 5 are protruded from the sides, the electrode area is smaller than in the embodiment shown in FIG. 2, and lead wires can be easily taken out.

FIG. 8 shows another embodiment of the present invention, in which when the terminal 6 is electrically connected to the lead terminal 31 of the reed switch 3, the resistance value when looking at the terminal 7 and the lead piece 32 is the temperature-sensitive magnetic material. 1 and the lead pieces 31 and 32 of the reed switch 3 are connected in series. Therefore, the temperature characteristic becomes as shown in FIG. 9, and the resistance value suddenly becomes infinite at Q') -Tel. If such a resistance R vs. temperature T characteristic is used, for example, it becomes a characteristic with a limiter function at temperature TCI,
There is an advantage that the limiter function processing circuit in the post-processing circuit is simplified.

FIG. 10 shows another embodiment of the present invention, in which the terminals 6 and 7 from the electrodes 5 and 4 of the temperature-sensitive magnetic body 1 and the lead pieces 3 and 32 of the reed switch 3 are connected in parallel with each other to form a composite terminal. 61
As shown in Fig. 11, the resistance R vs. temperature T characteristic as seen from
At the above temperature, the resistance value of the temperature-sensitive magnetic body 1 appears at the terminals 6 and 7'.

Further, FIG. 12 shows another embodiment of the present invention, and shows a temperature-sensitive magnetic body 1.
A non-magnetic spacer 8 is disposed on both sides. The operation of this type of magnetic circuit is as shown in FIG.
and the Curie temperature Tc is T (in 'rc, the temperature Tc is
The leakage magnetic flux φ4 from the outside and the magnetic flux φ3 from the outside cancel each other out, and the contact of the reed switch 3 turns off, and T >'rc
Then, as shown in FIG. 15, the magnetic flux from inside the permanent magnet 2.2' becomes dominant and the contact of the reed switch 3 is turned on. The characteristics of the combined resistance R and temperature T are shown in FIG.

FIG. 16 shows the embodiment of FIG. 12, in which both the lead terminals 6 and 70 from the electrodes are connected to the lead piece 31.3 of the reed switch 3.
FIG. 17 is a temperature T characteristic diagram of the combined resistance R.

<Effects of the Invention> As described above, according to the present invention, there are two types of temperature switches: a stable operation type temperature switch that operates at one Curie temperature as in the past, and a continuous detection temperature switch that continuously detects temperature such as a thermistor. Since it has both functions with one detection element without combining two detection elements, it is small and inexpensive, and the range of use is expanded.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view of an embodiment of the temperature detection element of the present invention;
FIG. 2 is an exploded external perspective view of FIG. 1. Figure 3 is a characteristic curve diagram showing the relationship between changes in magnetic flux density and temperature of the temperature-sensitive magnetic material used in Figure 1, and Figure 4 is a characteristic curve diagram showing the relationship between changes in resistance and temperature in Figure 3. 5 and 6 are explanatory diagrams showing the magnetic circuit and operation of the temperature detection element according to the present invention. 7 is an external perspective view of another embodiment of the present invention, FIG. 8 is an external perspective view of an embodiment of the pond of the present invention, and FIG. 9 is a relationship between terminal resistance and temperature in the embodiment of FIG. A characteristic curve diagram showing the relationship of changes; FIG. 10 is an external perspective view of another embodiment of the present invention;
FIG. 11 is a custom-made curve diagram showing the relationship between terminal resistance and temperature in the embodiment shown in FIG. 14 and 15 are explanatory diagrams showing the magnetic circuit and operation of the temperature detection element according to the embodiment of FIG. 12.
This figure is an external perspective view of an embodiment of the temperature detection element in which the other lead piece and the terminal are connected in the embodiment of FIG.
The figure is a characteristic curve diagram showing the relationship between the inter-terminal resistance and the temperature in the embodiment of Fig. 16, Fig. 18 is an external perspective view of an example of a conventional temperature detection element, and Figs. 19 and 20 are 1st
FIG. 8 is a characteristic curve diagram showing changes in temperature and magnetic flux density in the temperature detection element, and FIG. 21 is an external perspective view of an example of a composite temperature detection element that combines a conventional temperature detection element and a thermistor. In addition, 1: Temperature-sensitive magnetic material, 2: Permanent magnet, 3: Lead wire, 31, 32: Lead piece, 4, 5: Electrode, 6, 7
．． 7': terminal, 8 varnish 4-cer, 10: fixed point temperature detection element, 11: thermistor element. 12: Substrate. Fig. 1 3 Reed switch Fig. 2 Temperature (T) Te - Temperature (T) Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9c Fig. 10 Fig. 11 Temperature 1- Fig. 14 Fig. 19 Figure 20Figure 21

Claims (1)

[Scope of Claims] 1. Two terminals 6, 7 are externally connected to the reed switch 3 with lead pieces 31, 32 externally drawn out from the electrodes 4, 5 provided on both sides or at two locations on the outer periphery. In the temperature detection element in which cylindrical permanent magnets 2 are provided in contact with both sides of the pulled out cylindrical temperature-sensitive magnetic body 1, the lead piece 31
, 32 and the two terminals 6 and 7 are individually drawn out. 2. The temperature detection element according to claim 1, wherein one of the lead pieces 31, 32 and one of the terminals 6, 7 are electrically connected. 3. Each of the lead pieces 31 and 32 and the terminal 6,
Claim 1 electrically connected to each of 7.
Temperature detection element described in section.