JPH0522835Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a temperature detection device used for detecting the temperature of cooling water of an engine, etc., or detecting the temperature of air blowing from an air conditioner, a heater, etc.

<Prior Art> Conventionally, temperature control of cooling water for an automobile engine, etc. requires both a fixed point temperature control function and a function of detecting and displaying the temperature of the cooling water itself. Regarding the fixed point temperature control function, as shown in Fig. 5, annular permanent magnets 2 and 2' with the same inner and outer diameters are placed on both sides of the annular temperature-sensitive magnetic body 1 in a cylindrical body with the magnetic poles in the same direction. In combination, a fixed point temperature detection type temperature detection element in which a reed switch 3 is combined in this cylindrical body is mainly used. This temperature detection element is used to operate a motor fan such as a radiator of an engine by operating a contact point of the reed switch 3 at a set temperature of 80 to 90 degrees Celsius.

The principle of operation will be explained with reference to FIGS. 6a and 6b.

As shown in FIG. 7, the temperature-sensitive magnetic material 1 has a characteristic that the magnetic flux density B rapidly decreases at the Curie temperature _Tc . As shown in Figure 6a, if the ambient temperature T is lower than the Curie temperature _Tc , the permanent magnet 2,
The magnetic flux φ ₁ from 2' goes around through the lead of the reed switch 3. Here, the magnetic flux φ ₁ is sufficiently larger than the sensitive magnetic flux of the reed switch 3, and the contact of the reed switch 3 is in an on state. However, as shown in FIG. 6b, when the ambient temperature T reaches the Curie temperature _Tc , the magnetic flux that had been flowing through the temperature-sensitive magnetic body 1 changes to the reed switch 3 due to a change in the magnetic properties of the temperature-sensitive magnetic body 1. By leaking to the side, the magnetic flux φ ₂ in the opposite direction to the previous magnetic flux φ ₁ flows into the reed switch 3.
Occurs near the contact point. As a result, the combined magnetic flux becomes (φ ₁ −φ ₂ ), which is less than the sensitive magnetic flux of the reed switch 3, the contact is turned off, and the ambient temperature is detected.

On the other hand, regarding the temperature detection and display function, the thermistor element 4 is generally used as the temperature detection element as shown in FIG. The temperature is detected and displayed by changing it according to the ambient temperature.

<Problems to be solved by the invention> Normally, the temperature detection elements shown in FIGS. 5 and 8 are sealed in a protective case 5 having a screw attachment part 51, as shown in FIGS. 10 and 11, respectively. and is used. Protective case 5 like this
The two temperature detection elements sealed inside can be installed, for example, in two places inside the radiator, but with the recent trend toward smaller and lighter radiators, it is now required to combine the two protective cases into one. .

FIG. 12 shows a conventional example in which the above two temperature detection elements are sealed together in a protective case 5'.
The problem is that it becomes larger. Further, during assembly, a large number of man-hours are required for housing the temperature detection element, soldering connections between the pin terminal 52 and each lead wire, etc., resulting in an increase in cost.

The main purpose of the present invention is to provide a temperature detection device that has both fixed-point temperature detection and continuous temperature detection functions by utilizing the resistance versus temperature characteristics of a temperature-sensitive magnetic material.

Another object of the present invention is to provide a temperature detection device that is small in size, easy to assemble, and particularly has a high heat resistance at low cost.

<Means for Solving the Problems> The temperature detection device according to the present invention has a cylindrical body by combining annular permanent magnets on both sides of an annular temperature-sensitive magnetic body having predetermined characteristics. A reed switch is inserted into the temperature sensing element having first and second electrodes formed in two diametrically opposite regions of the outer circumferential surface of the temperature-sensitive magnetic body, and a temperature sensing element having first and second electrodes formed in two diametrically opposite regions of the outer circumferential surface of the temperature-sensitive magnetic body; first and second metal fittings each having a holding portion that is held between both sides and having a terminal; a third metal fitting having a V-shaped portion for holding one lead of the reed switch and having a terminal portion; and an insulating substrate to which the first, second, and third metal fittings are fixed, and one of the first and second metal fittings is integrated with a V-shaped part for holding the other lead of the reed switch. The temperature detection element is mounted between the holding parts of the first and second metal fittings so that the holding parts and the first and second electrodes are in contact with each other.

<Operation> The temperature detection device according to the present invention utilizes the magnetic flux density-temperature characteristics of a temperature-sensitive magnetic material for fixed point temperature detection using a reed switch, and forms first and second electrodes on the temperature-sensitive magnetic material to measure its resistance. - Continuous temperature detection is performed by making it possible to extract resistance value changes based on temperature characteristics. Furthermore, the temperature detection element is held and electrically connected only by mechanical compression using the first, second, and third metal fittings, thereby eliminating the need for soldering.

<Example> Fig. 1 shows an example of the temperature detecting device according to the present invention, Fig. 2 shows the temperature detecting element alone in Fig. 1, and Fig. 3 shows the holding part of the temperature detecting element in Fig. 2. are shown respectively.

In FIG. 2, permanent magnets 2 and 2' with the same inner and outer diameters are fixed on both sides of an annular temperature-sensitive magnetic body 1 with their magnetic poles oriented in the same direction to form a cylindrical body. A reed switch 3 is inserted into the hollow portion and fixed with adhesive or the like. Here, the temperature-sensitive magnetic material 1 is a Mn--Zn ferrite, and has properties as a ferromagnetic material (FIG. 4a) as well as properties as a semiconductor. In other words, its resistance versus temperature characteristic is as shown in Figure 4b, and the Curie temperature
As _Tc increases, the resistance vs. temperature characteristic shifts downward, and the resistance value at room temperature is 1kΩ~
It is about 10kΩ. Also, the rate of change in resistance is 1
It has a resistance change rate of around -4 to -5% per °C, which is equivalent to that of a normal thermistor.

The present invention utilizes the magnetic flux density versus temperature characteristic of the temperature-sensitive magnetic body 1 as well as the resistance versus temperature characteristic.
For this reason, the electrodes 11 and 12 are located in the outer circumferential area of the temperature-sensitive magnetic body 1 at opposite positions in the diametrical direction of FIG.
has been established. These electrodes are formed by applying ordinary silver paste and subjecting it to high temperature heat treatment. This electrode attachment process is performed on the temperature-sensitive magnetic body 1 as a single component before being assembled into the temperature sensing element shown in FIG. The temperature characteristic of the resistance value between the electrodes 11 and 12 has a monotonous decreasing tendency as the temperature increases, as shown in FIG. 4b, and this linearity can be used to continuously detect the temperature.

On the other hand, the reed switch 3 is set at the Curie temperature T _c
It has a fixed point temperature detection function where the contact opens at .

The holding part of the temperature detection element shown in FIG. 3 consists of metal fittings 6 and 7 made of a metal material having spring properties and a metal fitting 8 fixed to an insulating substrate 9 made of glass, epoxy, etc. by rivets 101 to 106. There is. The metal fitting 6 includes a holding part 61 having an arcuate cross section for holding the temperature detection element shown in FIG. 2, a terminal part 62, and a V-shaped clamp for holding the lead 31 of the reed switch 3 (Fig. 2). 63. Metal fittings 7
has a holding part 71 and a terminal part 72. Furthermore, the metal fitting 8 includes a clamping part 83 for clamping the terminal part 82 and the reed switch lead 32 (FIG. 2).
It has The holding parts 61 and 71 are each
Its curvature is matched to the curvature of the cylindrical body of the temperature detection element shown in FIG.
611 is provided and the temperature detection element alone is installed,
The structure is such that sufficient electrical contact between the holding parts 61 and 71 and the electrodes 12 and 11 is ensured.

Protrusions 612, 613, 712, and 713 are provided on both side edges of the holding parts 61 and 71, respectively, to prevent displacement of the temperature detection element in the length direction. Also,
The upper edges of the holding parts 61 and 71 are each expanded outward in an arc shape, allowing the temperature detection element to be mounted smoothly from above. Clamping parts 63, 83
The structure is such that the reed switch leads are mechanically crimped.

In FIG. 1, the temperature detection element itself is attached to the holding parts 61 and 7.
1, and after mounting, the clamping part 6 which clamps the leads 31 and 32 of the reed switch 3
3,83 are mechanically caulked. Further, in the temperature sensing element alone, the electrodes 11 and 12 of the temperature-sensitive magnetic body 1 are connected to the notches 71 and 71 of the holding parts 71 and 61, respectively.
1,611.

The metal fittings 6 and 7 are mainly made of a stainless steel spring material with high heat resistance. The terminal portion 62 is
It is a terminal that is electrically common to one lead 31 of the reed switch and the electrode 12 of the temperature-sensitive magnetic material 1, and the output of the reed switch 3, that is, the fixed point temperature detection signal, is output from between the terminal parts 62 and 82. can get. On the other hand, the resistance value of the temperature-sensitive magnetic body 1 can be obtained from between the terminal portions 62 and 72, and a continuous temperature detection signal can be obtained.

Furthermore, according to the present invention, heat resistance up to about 200°C is ensured because the soldering part of the conventional lead wire is eliminated and the lead wire is caulked or crimped. Moreover, it is easy to assemble and allows fixed point temperature detection and continuous temperature detection with one temperature detection element, making it more compact and lower cost than the conventional one that uses two temperature detection elements. can.

This temperature detection device can be used as it is in the state shown in Figure 1, but if sealing is required, only the terminal parts 62, 72, 82 can be placed in a protective case as shown in Figures 10 to 12. It is stored in a structure that exposes the

<Effects of the invention> According to the invention as described above, it is possible to provide a small, easy-to-assemble, and highly heat-resistant, low-cost temperature detection device that has both fixed-point temperature detection and continuous temperature detection functions with a single temperature detection element. .

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an embodiment of the present invention, FIG. 2 is a perspective view of a single temperature detection element in FIG.
FIG. 3 is a perspective view of the holding part of the temperature detection element in FIG. 1, and FIGS. Figure 5 is a perspective view of a conventional temperature detection element, Figures 6a and b are longitudinal sectional views for explaining the operation of the temperature detection element in Figure 5, and Figure 7 is a diagram of the temperature-sensitive magnetic material in Figure 5. Magnetic flux density-temperature characteristic diagram, No. 8
The figure is a diagram for explaining temperature detection using a conventional thermistor, and Figure 9 shows the resistance of the thermistor in Figure 8.
The temperature characteristic diagram, Figure 10, is a cross-sectional view of the temperature detection element shown in Figure 5 housed in a protective case.
Figure 1 shows a cross-sectional view of the thermistor shown in Figure 8 housed in a protective case, and Figure 12 shows a cross-sectional view of the temperature detection element shown in Figure 5 and the thermistor shown in Figure 8 housed in one protective case. Indicated by In the figure, 1 is a temperature-sensitive magnetic material, 2 and 2' are permanent magnets,
3 is a reed switch, 6, 7, and 8 are metal fittings, and 9 is an insulating board.

Claims (1)

[Scope of utility model registration request] An annular permanent magnet is combined on both sides of an annular temperature-sensitive magnetic material having predetermined characteristics to form a cylindrical body, a reed switch is inserted into the cylindrical body, and a reed switch is inserted into the cylindrical body. a temperature sensing element having first and second electrodes formed in two areas opposite in the diametrical direction; and a first and second temperature sensing element having a holding part that holds the cylindrical body between them from both sides in the radial direction and having a terminal. a third metal fitting having a V-shaped portion for holding one lead of the reed switch and having a terminal portion; and an insulating substrate to which the first, second, and third metal fittings are fixed. A V-shaped part for holding the other lead of the reed switch is integrally molded on one of the first and second metal fittings, and the temperature detection element is attached to the first and second metal fittings. A temperature detecting device, wherein the holding part and the first and second electrodes are mounted between the holding parts so that the holding part and the first and second electrodes are in contact with each other.