JPH063328A - Sensor - Google Patents

Abstract

PURPOSE:To obtain a sensor which has a simple structure and can be suitably constituted in a module or IC by forming metallic films which can detect environments on the opposite internal surfaces of a gap in which a coil wound around a magnetic core is exposed. CONSTITUTION:The magnetic core 15 of a magnetic head 9 is formed by joining two U-shaped core blocks 12 which are made of a high-density ferrite and respectively have recessed sections to each other by using a joining member 14 of glass, etc., with a gap 13 in between. Metallic films 17 made of such a material that can detects environments, namely, such a metal as iron-silicon crystalline alloy, iron-tantalum-carbon alloy composed mainly of iron, etc., which is sensitive against environment and apt to rust are formed and exposed on both internal surfaces 16 of the gap 13. The head 9 can be used as a rust sensor 8 for detecting that rust reaches its limit by specifying in advance the output value of the head 9 based on the relation between degrees of rust and output values.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensor, which is an element for converting various industrial quantities such as temperature and humidity into electric signals and taking them out. In particular, the present invention uses a metal film made of an environmentally detectable material. Regarding sensors.

[0002]

2. Description of the Related Art In general, various sensors to which semiconductors and the like are applied, such as humidity sensors and various gas sensors, are used for various industrial purposes. These sensors utilize the characteristic that the electrical resistance changes when gas or the like contacts or adsorbs to the semiconductor.

Further, in recent years, various proposals have been made to apply a thick film magnetic semiconductor as a sensor. This thick-film magnetic semiconductor uses a sintered body of a mixture of ferrite powder and a ruthenium compound, and its electric resistance responds to humidity and gas concentration, and its inductance depends on temperature but it depends on humidity and gas. It has independent properties. And such a sensor is made into various sensors by detecting the change of a magnetic characteristic.

Hereinafter, such a conventional sensor will be described with reference to FIGS.

FIG. 5 is a perspective view showing an essential part of the structure of a first conventional sensor, and FIG. 6 is a schematic view showing an essential part of the structure of a second conventional sensor.

First, the first conventional sensor 1 will be described with reference to FIG. 5. In the first conventional sensor 1, a thick film magnetic semiconductor 3 is formed on the outer side in the radial direction of an annular substrate 2 made of an appropriate material. Are fixed to form an annular sensor body 4. The sensor body 4 is provided with windings N01 and N02.

The first conventional sensor 1 formed as described above applies the excitation voltage E01 to the winding N01 to change the magnetic flux of the thick film magnetic semiconductor 3 to detect the voltage E02 induced in N02. It has become.

The second conventional sensor 1a will be described with reference to FIG. 6. In the second conventional sensor 1a, a thick film magnetic semiconductor 3a is fixed to one surface of a plate-shaped substrate 2a, and a sensor body 4a is provided. Are formed. Then, an appropriate AC magnetic field generator 5 is arranged in the lower part of the sensor body 4a in the figure, and a magnetic head 6 is arranged in the upper part, and the magnetic flux φ generated by the AC magnetic field generator 5 is converted into a minute voltage by the magnetic head 6. The reading and the minute voltage are amplified by the amplifier 7 and detected.

[0009]

However, in the above-described first conventional sensor 1, the sensor main body 4 is formed in an annular shape, or a yoke or the like is added to the sensor main body formed in a flat plate shape to form a closed magnetic circuit. Need to be formed. Therefore, there is a problem that the shape becomes large and it is not suitable for modularization of the sensor 1 and IC.

In the above-mentioned second conventional sensor 1a, a closed magnetic circuit is formed by the AC magnetic field generator 5,
Since the magnetic flux 6 is read by the magnetic head 6, there is a problem that the response sensitivity is poor.

The present invention has been made in view of these points, and overcomes the above-mentioned problems in the conventional ones.
It is an object of the present invention to provide a sensor that has a simple structure and uses a metal film made of a material capable of detecting an environment and that is suitable for modularization and IC integration.

[0012]

In order to achieve the above-mentioned object, the sensor of the present invention has a coil wound around a magnetic core made of a magnetic material and forms an exposed gap to form the gap. Is characterized in that a metal film made of a material capable of detecting an environment is formed on at least one of the facing surfaces facing each other.

[0013]

By the way, the sensor of the present invention is an application of the research of the magnetic head, which the present inventors have earnestly studied for many years.

That is, for example, in the study of a metal film or a magnetic material used for the facing surfaces of the gap of a MIG head and a thin film head, a material that has excellent magnetic properties but is easily rusted, that is, a material that can detect environmental conditions ( Hereinafter, many materials that can detect the environment) were found. Various sensors have been developed as articles that effectively utilize the characteristics of such materials and the manufacturing technology of the magnetic head.

That is, according to the sensor of the present invention having the above-described structure, when the metal film made of the environmentally detectable material formed on the facing surface of the exposed gap is placed in a predetermined environment, for example, When exposed to water, gas, etc.,
Deterioration, oxidation, corrosion, etc. start from the surface of the metal film, the gap width changes, and the magnetic characteristics change according to the change in the gap width, whereby the sensor can be obtained. Further, since the sensor has the shape of a magnetic head, modularization and IC integration can be easily performed.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a vertical cross-sectional view showing a main part of an embodiment of a sensor according to the present invention.

As shown in FIG. 1, the sensor 8 of the present embodiment.
Is composed of a magnetic head 9, an appropriate AC magnetic field generator 10, and an appropriate amplifier 11.

The magnetic head 9 has two substantially U-shapes having recesses made of high-density ferrite made of sintered ferrite such as polycrystalline Mn-Zn ferrite which has been subjected to hot isostatic pressing. Shaped core blocks 12, 12,
A magnetic core 15 is formed by joining the concave portions to each other with a proper joining member 14 such as glass via a predetermined gap 13. Then, on the surfaces of the gap surfaces 16 and 16 as facing surfaces of the magnetic core 15 which face each other, metal films 17 and 17 made of a material capable of detecting an environment are formed in an exposed state.

A suitable coil 18 is wound around a desired position of the magnetic core 15, and the coil 18 is connected to the amplifier 11.

Further, the magnetic core 15 is fixed to an appropriate case of ceramics, resin or the like, like a magnetic head used in a magnetic storage device (not shown).

Further, the environment-detectable material used for the metal film 17 will be explained. Examples of the material used for the metal film 17 include thick-film magnetic semiconductors, environment-sensitive rusty metals, and iron-silicon crystals. Alloy, iron-based iron-tantalum-carbon type, iron-nitrogen type, amorphous iron-tantalum-carbon type, iron-zircom-boron type, iron-carbon / iron-boron type, crystallize amorphous Iron-tantalum-carbon-silicon type, cobalt-based cobalt-zircon-boron type, cobalt-chromium-tantalum type, etc. may be used according to the purpose of use.

Next, the operation of this embodiment having the above-mentioned structure will be described with reference to FIGS.

FIG. 2 is an enlarged vertical cross-sectional view of the gap portion of the sensor of this embodiment, FIG. 3 is a schematic diagram showing the state of change in the gap portion due to the environment, and FIG. 4 is a magnetic characteristic accompanying a change in the gap width. It is a diagram showing the change of.

As shown in FIG. 2, the sensor 8 of the present embodiment having a predetermined gap width W00 exposed, for example, the rust sensor 8 is a metal film facing each other when placed in a predetermined environment. Moisture, gas, and the like adhere to the surfaces of the metal films 17, 17, and deterioration, oxidation, corrosion, etc., start from the surfaces of the metal films 17, 17. Then, as time passes, the deteriorated portions 19, 19 on the surfaces of the metal films 17, 17 expand as shown in FIG. 3, and the initial gap width W00 becomes W10 as shown in FIG.
Gradually expand to. As the gap width W00 changes, the magnetic characteristic of the sensor 8, for example, the relationship between the output and the frequency changes sensitively as shown in FIG.

Therefore, by defining the output value based on the relationship between the degree of rust and the output value in advance, the rust sensor 8 for detecting that the rust has reached the limit can be obtained.
Then, by correlating the progress of rust and the transition of the environmental state, it can be used as an environmental sensor.

Although the metal film 17 is formed on each of the gap surfaces 16 in this embodiment, the metal film 17 may be formed on only one of the gap surfaces 16.

In addition to the sensor 8 for measuring the integrated value of the environment like the sensor 8, by providing an appropriate heating means for moisture, gas, etc. adsorbed on the surfaces of the metal films 17, 17, When the metal films 17 and 17 are removed so that they do not continue to adhere to the surfaces, continuous measurement and repeated use can be made possible.

Further, such a sensor 8 can be easily miniaturized, modularized and integrated.

Further, the sensor 8 of this embodiment can use the manufacturing process of the MIG head, which is a kind of the magnetic head 9, the thin film head, etc., and the manufacturing technology and the manufacturing equipment can be shared, so that the development investment and the capital investment can be reduced. The burden is reduced, it can be manufactured easily and in large quantities, and MI
Rejected products generated in the manufacture of G heads or thin film heads can be recycled.

The present invention is not limited to the above embodiment, but can be modified as necessary.

[0032]

As described above, according to the sensor of the present invention, since the magnetic head can be applied to the sensor, it can be easily modularized and integrated into an IC and does not impose an economical burden. In addition, it has an extremely excellent effect that it can be easily mass-produced.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a main part of an embodiment of a sensor according to the present invention.

FIG. 2 is an enlarged vertical sectional view of a gap portion of the sensor of this embodiment.

FIG. 3 is a schematic diagram showing a state of change in the gap portion depending on the environment.

FIG. 4 is a diagram showing changes in magnetic characteristics with changes in gap width.

FIG. 5 is a perspective view showing a main part of a configuration of a first conventional sensor.

FIG. 6 is a schematic diagram showing a main part of a configuration of a second conventional sensor.

[Explanation of symbols]

 8 Sensor 9 Magnetic Head 10 AC Magnetic Field Generator 11 Amplifier 12 Core Block 13 Gap 15 Magnetic Core 16 Gap Surface 17 Metal Film 18 Coil

Claims (1)

[Claims] 1. A magnetic core made of a magnetic material is wound with a coil, an exposed gap is formed, and at least one of opposing surfaces of the gap is made of a material capable of detecting an environment. Forming a metal film of