JPS5923221Y2 - magnetic head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic head in which a laminated gap of one core half-open is opposed to and abutted against a portion of the core material of the other half-core.

In general, a magnetic head records and reproduces information by sliding against the magnetic tape, so the sliding surface with the magnetic tape gradually wears out and recording characteristics in high frequency ranges begin to deteriorate. As it progresses, recording characteristics begin to deteriorate in all frequency ranges.

To solve this problem, the wear resistance of the head should be increased to reduce the amount of wear and to make the wear more uniform.

For example, a stereo magnetic head used in an audio cassette tape recorder has a track width of about 0.6 mm, but if a core material with a plate thickness of 0.6 mm width is used to form the track, eddy current loss is large. There is a significant decrease in electromagnetic conversion efficiency.

Therefore, in a normal magnetic head, for example, the plate thickness is 0.1
Four sheets of 5 mm wide core material are laminated to ensure a track width of about 0.6 mm, thereby reducing the eddy current loss and increasing electromagnetic conversion efficiency.

In this case, since the laminated core materials need to be electrically insulated from each other, an electrically insulating adhesive is attached to the surface of the high magnetic permeability material (permalloy, sendust, etc.).

Therefore, the tracks of the magnetic head are in a state in which the high magnetic permeability material and the adhesive are alternately laminated.

Under such conditions, conventional magnetic heads replace the high permeability material with permalloy to improve wear resistance.
It was replaced with a hard permalloy, sendust, etc. that has higher wear resistance.

As for the adhesive, a resin having lower wear resistance than the high magnetic permeability material has been used with emphasis on adhesive properties.

However, the abrasion resistance of the adhesive also plays a role in the abrasion resistance of the head core.

Therefore, by forming the adhesive having higher wear resistance than the high magnetic permeability material to be sufficiently thinner than the high magnetic permeability material, the wear resistance can be increased without impairing the electromagnetic conversion efficiency.

FIG. 1a is a perspective view of the magnetic head 1, and FIG. 1a is a perspective view of the magnetic head 1.
2 is an enlarged front view of the tape sliding surface 2 when viewed in the direction of arrow A. FIG.

In FIG. 1, 3a and 3b are core materials made of a high magnetic permeability material, and 4a and 4b are adhesives for bonding the laminated core materials.

The stacked and glued core halves 5゜6 butt together at the magnetic gap 7, but in the conventional core, the core material 3a is connected to the core material 3b and the adhesive 4a is connected to the adhesive 4b through the magnetic gap 7. They were facing each other.

For this reason, even if the wear resistance of the adhesives 4a and 4b is made higher than that of the core materials 3a and 3b, the distance between adjacent adhesives is 1.
If 1 is large, the expected effect cannot be obtained.

Therefore, in order to reduce the interval 11, the core materials 3a and 3b are
It is possible to improve the wear resistance by reducing the thickness tl of the core material and laminating multiple layers of the core material, but depending on the material of the core material, it is difficult to reduce the thickness tl, and even more If this is done, the number of steps for laminating the core material increases, resulting in increased costs.

The magnetic head of the present invention eliminates the above-mentioned drawbacks and has high wear resistance without increasing the lamination process, and will be explained below with reference to the drawings.

FIG. 2a is a front view of essential parts of the magnetic head according to the first embodiment of the present invention, shown in the same manner as FIG. 1.

In Fig. 2a, items 8a, 8b, and 8b' are core materials made of high magnetic permeability materials such as Hermalloy and Sendust, and the thickness of the core materials 8a and 8b is tl, and the thickness of the core material 8'b is is t
2 (however, t2;-) tl).

Reference numerals 9a and 9b denote adhesives interposed in gaps between adjacent core materials in order to bond the laminated core materials together.

Adhesives 9a and 9b are used to improve abrasion resistance in addition to adhesiveness and electrical insulation (core materials 8a, 8b, 8
In order to improve the wear resistance compared to the core material 'b), fine powder with high wear resistance such as SiO2, Al2O3, B4C5SiC, etc. is added to the epoxy resin at a weight ratio of 20% to 80% (this is just an example. The higher the wear resistance, the better)
.

And the thickness of the adhesive layer is 0.004~0.005mm
(can be ignored compared to the thickness of the core material).

One of the core halves 10 laminated and glued [the core material 8a has a thickness of tl, and when four pieces are laminated, the thickness of the core half 10 is 4t
1] and the other core half 11 [core material 8b has a thickness t
The core material 8'b at both ends has a thickness of t2 (+-41).
The thickness of the core half 11 is 4t1 with 2 pieces, that is, 5 pieces in total.
] are brought into contact with each other at the magnetic gap 12 to form a core.

For this reason, the lamination gap (adhesive part) of one core half-closed
is opposed to the other core half-closed portion of the core material through the magnetic gap 12.

Therefore, in the vicinity of the magnetic gap 12, the adhesives 9a and 9b formed in the lamination gap are close to each other.
The distance between adjacent adhesives can be regarded as 1□ (it can be 1°<1□).

In this way, the magnetic head of the present invention does not reduce the thickness of the core materials 8a and 8b, and also shortens the distance between adjacent adhesives in the vicinity of the magnetic gap.
This can improve wear resistance and shorten the core material lamination process.

FIG. 2 is a front view of essential parts of a magnetic head according to a second embodiment of the present invention, which is the same as that shown in FIG. 2 except that adhesives 14a, 14b, etc. are formed at an angle to each other.

That is, 13a and 13b are core materials with a thickness of t1, 13'b is a core material with a thickness of t2 (:l:+t1), and 15 is a magnetic gap.

Figure 3 shows the result of the wear test when the core half-dead 10 shown in Figure 2a or the core half 5 shown in Figure 1 is cut along the dashed-dotted line BB' and viewed in the direction of discoloration C. FIG.

In FIG. 3, a magnetic tape (not shown) slides on the right end of the core material 8a or 3a, and the core material 8a or 3a is worn down by a depth D due to the sliding.

In the magnetic head of the present invention, in addition to the adhesive 9a shown in FIG. 2a, the adhesive 9b is hard to wear out, and the magnetic tape (not shown) has hardness differences within a narrow area. Because the tape does not adhere very faithfully to uneven surfaces, the tape sliding surface becomes as shown by the solid line 16 after the wear test, and the amount of wear decreases.

On the other hand, in the Jukyo magnetic head already shown in Figure 1, there is no reinforcement corresponding to the adhesive 9b, so the tape sliding surface after the wear test is at the position shown by the broken line 17, which shows a large amount of wear. .

Table 1 shows the differences in specific configurations between the magnetic head of the present invention and the conventional magnetic head, and shows the amount of wear after the wear test (after running the magnetic tape at a tape speed of 4.75 cm/s for 200 hours). D (μm) is indicated by *.

In Table 1, test 1-1 uses hard permalloy as the core material, and test 2 uses sendust as the core material.

As a result, the magnetic head of the present invention achieves almost all of the wear resistance properties obtained by laminating 6 pieces of hard permalloy core material with just 3 to 4 layers, and laminates 4 pieces of Sendust core material. It can be seen that the abrasion resistance properties previously obtained by laminating only 2 to 3 sheets can be closely approximated by laminating only 2 to 3 sheets (compare the ``number of core materials'' and ``amount of wear'' sections in Table 1). ).

As described above, since the magnetic head of the present invention does not need to reduce the thickness of the core material and make it multilayer, it is possible to use a high permeability material that is difficult to make into a thin plate, and the manufacturing process due to multilayering can be simplified. Complications can be avoided.

It is also possible to reduce manufacturing costs and improve wear resistance.

[Brief explanation of the drawing]

FIG. 1a is a perspective view of a magnetic head, FIG. 1 is an enlarged front view of the core of a conventional magnetic head, and FIG. 2a is a diagram of a core of a magnetic head according to the first embodiment of the present invention. FIG. 2 is a front view showing an enlarged portion of the core of the magnetic head according to the second embodiment of the present invention, and FIG. 3 shows the state of wear of the core of the magnetic head. Cross-sectional view. In addition, in the figure, 8a, 8b, 8'b, 13a
, 13b, 13'b...-core material, 9 a, 9
b, 14 a, 14 b...adhesive, 10.11
...Core half-off, 12.15...Magnetic gap.

Claims (1)

[Scope of utility model registration request] A first core half-hole is made by laminating a plurality of core materials made of high magnetic permeability material and the gap formed by the lamination is bonded with an adhesive; In the magnetic head having a second core half-dead which forms a magnetic gap by abutting against each other, the adhesive has a wear resistance higher than that of the core material by adding fine powder to the resin to increase the wear resistance. magnetic material, characterized in that the thickness of the adhesive layer is sufficiently thinner than the thickness of the core material, and the adhesive layer is opposed to the half-dead core material to be butted. head.