JPH03293704A - Magnetic head core for prepaid card - Google Patents

Abstract

PURPOSE:To get stable regeneration/recording properties with large magnetic flux density and high permeability by stacking plural sheets of quenched belts of Sendust alloy, in each of which the structural form at the cross section in thickness direction in granular structure at the center and is columnar structure at the top and bottom, in the thickness direction. CONSTITUTION:A magnetic head core is made by stacking plural sheets of thin belts of Fe-Si-A alloy, in each of which the structural form at the section in thickness direction is granular structure at the center and is columnar structure at the top and bottom in thickness direction. That is, in case of having stacked thin belts, even if the number of lamination layers is increased, the magnetic flux permeates enough into the all thin belts in the direction of lamination. Accordingly, a magnetic head core, wherein Ac permeability is flat regardless of the thickness of a board (the number of lamination layers), can be obtained. Hereby, the magnetic properties of high magnetic flux density and high permeability can be obtained, and the foregoing signals can be processed without leaving them at the time of overwrite, and the errors in the writing to and the reading from a prepaid card can b reduced.

Description

[Detailed description of the invention] [Industrial application field] The present invention is a telephone card and a pachinko card.

The present invention relates to a magnetic held core used for recording and/or reproducing so-called prepaid cards such as stored cards.

[Conventional technology]

2. Description of the Related Art Magnetic head cores have conventionally been used to perform recording and/or reproduction on magnetic surfaces such as magnetic tapes and prepaid cards. As the material for this magnetic helad core, Fe-5i-AI alloy (generally called sendust) is widely used because it has excellent magnetic properties, wear resistance, and corrosion resistance. This Pe-5i-A
The method for manufacturing a magnetic helad core using an I-based alloy is
An ingot of 5i-AI alloy is manufactured, and this ingot is processed into a flat plate by hot working etc., and then processed into a predetermined shape by machining such as cutting and grinding, and the distortion during processing is removed. 7. In addition, for the purpose of developing appropriate θ characteristics, a manufacturing method using an annealing method, a method for manufacturing a magnetic head core using so-called bulk material, or a method of manufacturing a magnetic head core using a molten metal of re-5i-AI alloy using a roll method. Super rapidly cooled and thin strip and L7
, After annealing if necessary, a large number of cores cored from this 'fR band are bonded and laminated with adhesive, and then polished [Publisher of "Latest Magnetic Head"]:
Mimac Data System, published 150 October 1980, reference 1, etc.

On the other hand, in prepaid cards that have been used in recent years, the locking force (tlc) of the magnetic medium on the magnetic surface is conventionally about 80
00 e has improved to more than 27500 e.

[Problem to be solved by the invention]

By the way, when recording and/or reproducing is performed on a prepaid card whose magnetic surface has a high coercive force with a magnetic head core or laminated magnetic head core using the above-mentioned bulk material, before the card is saturated, The magnetic helad core becomes saturated with the input current, and when overriding (writing a different signal over a signal that has already been written to the magnetic medium), the previous signal may remain.

As a result, writing and reading errors occur. On the other hand, in recent years, various kinds of printing have been performed on the surface of prepaid cards, and the thickness of the printing layer has become thicker. For this reason, the distance between the magnetic medium on the magnetic surface and the magnetic head core inevitably increases, and a magnetic head core that generates stronger magnetic flux and has higher magnetic permeability is required.

Furthermore, from now on, there will be a demand for prepaid cards that can be used for multi-purpose products, and in order to meet this demand, it will be necessary to improve the security of the information recorded on the card. It is necessary to further increase the magnetic force or to make the input/output signals have complex waveforms. There is also a demand for improved card recording density and improved playback/recording speed.

In order for a magnetic head to meet these demands, a magnetic rad core is required that has a large magnetic flux density, high magnetic permeability, and stable read/write characteristics from low frequencies to high frequencies.

Therefore, in order to meet the above demands, the present inventors aimed to develop a magnetic helad core with high magnetic flux density and high magnetic permeability, using Fe-5i-AI which has excellent wear resistance and corrosion resistance.
We have carried out repeated research using these alloys7, focusing in particular on the behavior of their magnetic properties. As a result, we confirmed that a magnetic head core made of laminated thin strips has superior magnetic properties compared to a magnetic head core made of bulk material, and also found that even with a laminated magnetic head core, there is considerable variation in magnetic properties. did. After investigating the cause, we have completed the present invention.

[Failure to solve the problem]

The magnetic head core for prepaid cards according to the present invention, which was developed as described above, is made of an Fe-3i-AI alloy whose cross-sectional structure in the thickness direction is granular at the center and columnar at the top and bottom. It is formed by layering a predetermined number of 81 layers in the thickness direction.

[Example] Si: 8.5wt%, Al: 5.5wt%, remaining Fe
A ribbon according to the present invention having a thickness of 60 μm was produced from a molten Fe-3i-A1 alloy consisting of the following by a twin roll method at a linear velocity of 200 m/min. The cross-sectional structure in the thickness direction of the obtained ribbon is shown in 1i (not shown in al.) As is clear from 1, the ribbon according to the present invention has a cross-sectional structure in the thickness direction in The upper and lower parts of the granular fiber are formed of a columnar structure.In contrast, for comparison, the linear velocity of 50
The cross-sectional structure in the thickness direction of the ribbon obtained under the normal conditions of 0n+7 minutes is shown in FIG. One weave in the cross section of the ribbon is formed only of columnar structures grown from the upper and lower sides.

When manufacturing an amorphous ribbon using the liquid quenching method as described above, it is better to increase the cooling rate as much as possible (increase the &S rate) to obtain a stable supercooled state, so the linear velocity is usually at least 300 m for 7 minutes or more. I'm keeping it.

However, in the case of a crystalline ribbon such as Fe-5i-AI alloy, the linear velocity is 300 m 7 in the twin roll method.
If the cooling rate is more than 100 min, a thin strip of fragments and Ill@ as shown in Fig.
It was found that at a linear velocity of 00 m 7 minutes, the cross-sectional structure becomes a thin strip as shown in 1.1(a). Furthermore, in order for each structure in the cross section to be stable and to show thickness, it is necessary to
It has been found that a linear velocity of between 230 Mon/min is preferred7. Furthermore, the cross-sectional weaving shown in Figure 1(a) cannot be obtained by cooling the ribbon from one side, as in the single-roll method, no matter how fast the cooling rate is. It was found that cooling from both sides was necessary.

The second part focuses on increasing the thickness of the core material, μIkllz and 1
The relationship between the AC i3-rate at z100kllz and the core material obtained by laminating the ribbons according to the present invention obtained above,
It is a diagram (not shown) in comparison with a core material obtained from bulk material.

As is clear from this figure, the thickness of the core material in which thin strips according to the present invention are laminated is 60Ijm + 1ms+.

In the case of 2■-, as shown in the measured values, no decrease in AC permeability was observed due to an increase in the number of laminated sheets. On the other hand, for the core materials obtained from bulk materials used for comparison, the magnetic permeability of the core materials with a thickness of 0.2 mm + 1 mm and 4 mm decreases as the thickness increases, as shown by the measured values. It has clearly decreased due to the effect. This means that when the ribbons according to the present invention are laminated, no matter how much the number of laminated sheets is increased, the magnetic flux will sufficiently penetrate into all the ribbons in the 81-layer direction. ), a magnetic core with flat AC permeability can be obtained.

The thickness of the quenched ribbon of sendust alloy in the present invention is 1
The thickness is preferably 100μ or less.
If it exceeds this, the material will become brittle because the quenching effect will no longer be obtained during production of the ribbon.

On the other hand, the thickness of the core is preferably 0.1 mm, and if the thickness is less than 0.1 mm, the AC permeability will be as shown in Figure 2.
There is no difference in comparison with bulk material (this is because the meaning of creating a core by laminating thin ribbons is lost).

Next, the thin ribbons according to the present invention were laminated to a thickness of 2.4 m+w and molded to produce a magnetic nodal core. The characteristics of the magnetic head core of the present invention are that the coercive force of the magnetic medium on the magnetic surface is high (I (c: 27500 e)
We conducted a survey using a prepaid card. For comparison, we also conducted the same investigation using a magnetic core molded into the same shape using bulk material. These results are combined in Figure 3 (a
) and shown in FIG. 3(b).

In FIG. 3(a), the horizontal axis shows the current value during recording, and the vertical axis shows the card output during playback. This figure shows that the smaller the current value during recording and the larger the card output during playback, the better the characteristics of the magnetic head core.As is clear from the figure, the magnetic head core of the present invention is made of bulk material. The current value is smaller and the output is larger than the magnetic node core. That is, the magnetic nodal core of the present invention can record with a small current value and reproduce with a large output, and has excellent characteristics.

In addition, the characteristics shown in 3rd IA et al.
In the figure, the horizontal axis is the current value passed through the magnetic nodal core, and the vertical axis is the magnetic flux generated from the gap of the magnetic nodal core (standard magnetic flux). In this figure, the culm has a large fine axis, and the magnetic flux generated from the magnetic henode core is large, which means that the recording characteristics are good. Therefore, as is clear from the figure, the magnetic hemlock core of the present invention is superior to the bulk material magnetic hemlock core in this characteristic as well.

Furthermore, Fig. 4 shows that changes in Fe-5i-A1 alloy have no effect on AC permeability, magnetic flux density, and rust formation.
The thin strip (thickness 60/711) according to the present invention has a thickness of 0.2
11 is a diagram showing a comparison between a core material laminated in 1111 and a core material made of bulk material having the same thickness. FIG. According to this diagram,
Although there is a tendency for art materials to be shared, there are clear differences in the extent of this. In other words, the decrease in AC magnetic permeability due to the increase in magnetic flux density (increase in the amount of Fe) follows the same trend, but the absolute 1ti is
The core material involved in the present invention is much larger than the bulk material. This means that the core material according to the present invention can have a high magnetic flux density and obtain a magnetic permeability that is the same as or higher than that of the bulk material at a low magnetic flux density. -By increasing Fe of A1 alloy, high magnetic flux density and high i
It is possible to produce a head core having a ratio of 31%. In addition, the core material according to the present invention has far fewer rust spots and has excellent corrosion resistance than a core material made of bulk material if the same amount of Fel is used. The reason why the core material according to the present invention has excellent corrosion resistance is thought to be because the crystal grains are much smaller (and there are fewer casting defects and processing defects) compared to bulk core materials.

In the above explanation, the re-5i-A1 alloy was explained as a representative example of the sendust alloy according to the present invention, but other alloys include Fe-5i-Co, Fe-5i-Ge, F
Of course, sendust alloys such as e-^1-Ga are also applicable.

〔Effect of the invention〕

As described above, according to the magnetic head core for prepaid cards according to the present invention, magnetic properties of high magnetic flux density and high magnetic permeability can be obtained, so that it can be used for prepaid cards with high coercive force of the magnetic medium on the magnetic surface, and for various types of magnetic media on the surface. When overriding prepaid cards printed with , multi-purpose prepaid cards with a high density of recorded information, etc., it is possible to process without leaving any previous signals, thus preventing errors in writing to or reading from the prepaid card. can be reduced.

[Brief explanation of drawings]

FIG. 1(a) is a cross-sectional structure diagram in the thickness direction of the Fe-3i-A1 alloy ribbon of the present invention, and FIG. 1(b) is the Fe-3i-A1 alloy ribbon of the comparative example.
-3iA1 alloy ribbon cross-sectional structure diagram in the thickness direction, Figure 2 shows the increase in core material thickness and μm k II z and μm
Figure 3 (a) is a diagram showing the relationship between the current value during recording and the card output during playback. Fig. 4 shows the relationship between Fe1l, AC permeability, magnetic flux density, and rusting of Fe-5i-A1 alloy. It is a diagram.

Claims (1)

[Claims] For a prepaid card, characterized in that it is formed by laminating a predetermined number of quenched ribbons of Sendust alloy in the thickness direction, each of which has a granular structure in the center and a columnar structure in the upper and lower parts. magnetic head core.