JPS60260468A - Composite temperature sensitive ferrite material - Google Patents

Abstract

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

Description

Detailed Description of the Invention ■ Background Technical Field of the Invention The present invention relates to a composite temperature-sensitive ferrite material, and more particularly, to a composite temperature-sensitive ferrite material formed by laminating and integrating a plurality of plate-shaped ferrite materials with different Curie points. Regarding ferrite materials.

Prior art and its problems So-called temperature-sensitive ferrites that utilize a single point of Ferrai I are known, and are used as various temperature sensors.

For example, a temperature-sensitive reed switch (Special Publication No. 50-40231
No., Special Publication No. 58-40809, etc.), temperature display device (
/ Publication No. 40-30872, JP-A-54-85080
etc.), heat-sensitive valves (Utility Model Publication No. 57-9570, etc.), etc.

Among these, temperature actuators that mechanically or electromagnetically operate devices such as heat-sensitive valves at a set temperature are used to adjust the amount of hot water in a shower, etc. in a predetermined temperature range.
1! There are some devices that provide peace of mind by systematically operating according to the temperature.

However, since temperature-sensitive ferrite exhibits a rapid change in magnetic flux density near the single Curie point, it can only open and close at a single temperature.

On the other hand, the valve described in Utility Model Publication No. 57-9570 has a plurality of different ferrites with a single Curie arranged separately and independently, and closes the plurality of valve seats by operating according to the temperature of each ferrite. Since the JT has a step-like opening and closing operation, it is difficult to finely adjust the temperature, and in order to make fine adjustments, the JT requires a complicated mechanism and is large in size.

In this case, the flow rate can be adjusted by bonding and integrating multiple ferrites with different Curie points and operating this integrated body according to the temperature in the magnetic field, but in this case, the flow rate can also be adjusted using a stem-like flow rate. There are similar drawbacks.

+1 Object of the Invention The object of the present invention is to provide a composite temperature-sensitive ferrite I material that can perform continuous temperature detection and operation in a predetermined temperature range, especially when used as a temperature actuator.

Such objects are achieved by the invention described below.

That is, the present invention provides a composite temperature-sensitive film made by laminating and firing a plurality of ferrite plate-shaped bodies having different Curie points.

In light materials, component diffusion occurs between the plate-like bodies so that the temperature characteristics of the magnetic flux density unique to each plate-like body virtually disappear and continuous temperature changes in magnetic flux density occur in the material as a whole. This is a composite temperature-sensitive ferrite material characterized by:

■Specific structure of the invention Hereinafter, a specific configuration of the present invention will be explained in detail.

The composite temperature-sensitive ferrite material of the present invention is formed by laminating plate-like bodies of different ferrites.

The ferrite material constituting each plate-like body is Mn-based, Ni-
Various known soft ferrite compositions such as Cu-Zn type and Cu-Zn type can be used.

In this case, the Curie point of ferrite is determined by the types of main components and their ratios.

For example, Mn-Zn system, MnOZnOFe2 03 Z (However, x+y+Z=loo) Then, the Curie point Tc ("C) is given below.

Tc = 1 2 . 8 (x-2z/3)-358 Such a formula is also known for other lAI compositions, and from these, the ferrite composition with the Kichorian 2.

Note that each of these ferrite compositions may contain various known impurities.

Although various methods can be used to produce a plate-shaped body of ferrite with a single point of curri from various fields, in order to facilitate the production of the composite material of the present invention, a sheet mixed with a binder is used. It is preferable.

In this case, one of various resins can be used as the pinter, and for example, polyhinylpetyral, ethyl cellulose, etc. or TLF are suitable. And the intermixing ratio is 3
~10%.

Note that the sheet may be prepared according to the usual method.

In this case, when producing the sheet, toluene, xylene, inpropyl alcohol, etc. are suitable as the solvent used for slurrying. And slurry viscosity is 1000~30
The solvent source 1K is selected depending on the powder and binder used so that the amount is about 00 cp. For ferrite powder, the amount added is preferably 30 to 60% of the material.

A sheet is then produced from this slurry according to a conventional method.

Such a plate-like body usually has a thickness of about 0.1 to 2 mm.

The plurality of ferrite plates used are selected so that they each have a different Curie point within a temperature range that includes the required sensing temperature range.

In this case, the range lri@ of one point of Curie is usually set to about +20 to +.50°C from the detection temperature range of -20 to -50°C. The curri point of each ferrite plate is usually set to differ by 2 to 5 degrees Celsius.

Such ferrite plate-like bodies are usually arranged in the order of the height of one curri point and are laminated and integrated.

In this case, the thickness and filling rate of each ferrite plate are:
They may be the same or different.

The ferrite plate bodies are laminated and integrated so that component diffusion, which will be described later, occurs.

In other words, they are integrated by firing.

As mentioned above, the plate-like body is preferably composed of a mixture of ferrite and a binder.
At this time, the laminate of each plate-like body may be heated and fused in a heated roller, and if necessary, heat treatment may be performed thereafter.

Such heat fusion may be performed at 500 to 1200°C.

Component diffusion occurs between the plate-shaped bodies by firing. As a result, when we measured the temperature characteristics of the magnetic flux density (particularly the saturation magnetic flux density) of the entire composite material, we found that, as shown in curve a in Fig. Based on one point (Tc1, Te3, Tc3, Tc4), the temperature characteristic characterized by a step-like shoulder substantially disappears, and a continuous characteristic curve close to a gentle straight line is drawn.

On the other hand, when the above-mentioned plate-like bodies are simply pasted together, each plate-like body has a single point (Tc1), as shown by the curved line b in FIG.

The characteristic curve is a stamp-like or polyline-like characteristic curve in which abrupt step-like changes in the saturation magnetic flux density at Tc2, Tc3, Tc4) are superimposed.

At this time, the actuator performs stepwise temperature detection and operation.

In such a case, in the composite material of the present invention, the slope of the characteristic curve is -10 to -500 G/℃ in the sensing temperature range.
It can be done.

Further, the variation width of the slope can be set to 30% or less within the detection temperature range.

Such temperature characteristics of magnetic density only need to be expressed macroscopically in the composite material as a whole. For example, by magnetizing in a direction perpendicular to the stacking direction of the plate-shaped bodies, However, when magnetic flux changes are measured with a much smaller resolution, it does not matter whether or not the central part of the plate-shaped body maintains its unique temperature characteristics.

The temperature characteristics of the magnetic flux density in such a microscopic field depend on the degree of progress of component diffusion between the plate-shaped bodies. 'And even if the degree of progress of component diffusion is low and the central part of each plate-shaped body maintains a single Curie point unique to the plate-shaped body, the composite material as a whole will not have the gentle temperature characteristics described above. Sometimes.

In such cases, magnetization is performed in a direction perpendicular to the stacking direction of the plate-like material, and if a high-resolution sensor such as a Hall element is used, a magnetic field can be applied in a direction perpendicular to the stacking direction of the composite material. However, changes in magnetization can be detected locally, making so-called digital temperature detection possible.

Even in this case, it is sufficient if the material as a whole exhibits the above-mentioned temperature characteristics of magnetic flux density.

On the other hand, the degree of progress of component diffusion increases, and the central part of each plate-like body has a +7. (However, even in this case, there is no problem as long as the material as a whole exhibits the gentle temperature characteristics described above.)

■Specific effects of the invention The composite material of the invention has a magnetic flux F: f, 7 as a whole of the material.
fff7・f37so, -4drit・4′dust・i・
Since it has a curve, when used as a temperature actuator, it can perform continuous operation depending on the temperature within the required detection temperature range.

FIGS. 2 and 3 show an example of using the material of the present invention in a heat-sensitive valve for a hot water shower.

In both figures, a valve housing passage 4 is formed in the hot water passage 3. A permanent magnet 2 is arranged in the valve passageway 4,
The composite material 1 of the present invention is placed within this magnetic field so as to be movable orthogonally along the valve housing path.

Now, when the water temperature in the flow path 3 is lower than the detected temperature range, the composite material 1 is attracted by the permanent magnet 2 and closes the valve housing path 4.

When the water temperature rises and falls within the detection temperature range, the composite material 1 opens and closes the valve passageway 4 for a predetermined length with the balance of the attractive force from the permanent magnet 2 and gravity.

In addition, the temperature actuator can be used in five different ways. In addition to such mechanical operation, other members may be operated using changes in the magnetic signal generated by the composite material.

Furthermore, as described above, digital detection is also possible when no component diffusion occurs in the center of each plate-like body.

The present inventors conducted various experiments to confirm the effects of the present invention.

An example is shown below.

Experimental example MnOZnOFe2 03 Z (x+y+z=loO) In, change x and z, and Tc=0, 3.

5.8,10,13.15.18,20°23.25,
28, 30, 33.3.5, 38°40.43, 45,
Twenty-five sheets were obtained at temperatures of 48, 50, 53, 55°, 58, and 60°C.

Each sheet was made of polyhinyl butyral (PVB) and ethyl cellulose (EC), the binder mixing ratio was 3.5% PVB and 1.5% EC, and the thickness was 1.0 mm.

These sheets were heat-sealed at 80° C. and then fired to obtain the composite material of the present invention.

The temperature characteristic curve of the saturation magnetic flux density of this composite material has a slope of 35 to 65 G/'C at 10 to 50 degrees Celsius! , and its fluctuation rate was 30%. When this was attached to the valve shown in Figures 2 and 3, it was possible to control the water temperature extremely well.

[Brief explanation of drawings]

FIG. 1 is a graph for explaining the temperature change in the saturation magnetic flux density of the composite temperature-sensitive ferrite material 4 of the present invention, and FIGS. FIG. l... Composite temperature-sensitive ferrite material; 1゜2... Permanent magnet. 3...Flow path. 4...Benkiro Applicant TDC Co., Ltd. + Agent Patent Attorney To Ishino] Yang Figure 1 Overflow Cliff Figure 2

Claims (1)

[Scope of Claims] (1') In a composite temperature-sensitive ferrite material formed by laminating and firing ferrite plates having different I numbers by a single point, the magnetic flux unique to each plate as a whole is A composite temperature-sensitive ferrite material characterized in that component diffusion occurs between plate-shaped bodies so that temperature characteristics of density substantially disappear and continuous temperature changes in magnetic flux density occur. (2) The composite temperature-sensitive ferrite material according to claim 1, wherein the plate-shaped body has a thickness of 0.1 to 5+w+a.