JPS6341610Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to the structure of a magnetic head.
This is suitable for magnetic heads that sometimes record with a narrow recording track width on magnetic tapes with high coercive force.

Conventionally, magnetic heads using ferrite materials have higher electrical resistivity than metal materials such as Sendust alloy, Permalloy, and Amolyphas alloy, so they have low eddy current loss and good high frequency characteristics, but they have low saturation magnetic flux density. Because of the low coercive force, when recording signals on a magnetic tape with high coercive force, there was a problem that the head core would become saturated.

Furthermore, magnetic heads made of metal materials such as Sendust alloy have a high saturation magnetic flux density, but have a low electrical resistivity, resulting in large eddy current loss and poor high frequency characteristics.

Furthermore, the magnetic head made of this metal material suffers from severe wear due to sliding with the tape and has a short head life.

In view of the above-mentioned problems, the present invention aims to solve the above-mentioned problems by combining a ferrite material and a metal material.One embodiment of the present invention will be described below along with the manufacturing process with reference to the drawings.

In the drawing, 1a is a main core made of a metal material such as Sendanst alloy or high permalloy with high saturation magnetic flux density, and 1b is a main core made of a ferrite material 8 that has excellent magnetic properties in a high frequency band and a non-magnetic material such as glass. This is an auxiliary core formed by 7 and 7.

The cores 1a and 1b are designed and processed to have the same shape as follows.

That is, the winding groove 2 is provided in the center, and of the two surface portions divided into front and rear portions, the surface portion 3 is used as the front gap forming surface, and the other surface portion 4 is used as the rear gap forming surface.

Here, what is important about the auxiliary core 1b is that it is composed of the diagonally shaded portion 7 that constitutes the surface portion 3 and the portion 8 from the surface portion 4 to the vicinity of the surface portion 3, and if the portion 8 is made of ferrite, the portion 7 It is formed using glass by fusion-bonding the glass to the ferrite.

Furthermore, the ferrite portion 8 has a tapered shape such that its tip extends near the surface portion 3 in order to improve the head efficiency, and has an angle θ with respect to the portion 7 from the point of view of the head shape.

FIG. 2 shows the core half 1 in which the cores 1a and 1b are stacked and integrated into one body. Lamination can be carried out by forming extremely thin layers of resin or glass and heat bonding.

That is, this core half 1 has a sendust core portion 1a having a thickness T constituting the head track width.
A ferrite core portion having a shape and thickness that enhances magnetic circuit efficiency is disposed on the side surface near the front gap forming surface 3 of the sendust core portion 1a, and a glass portion 7 provided at the tip of the ferrite core 1b. This is a structure in which the area of the gap forming surface 3 is increased by the thickness T'.

The two core halves 1, 1' thus formed
are symmetrical with respect to the gap plane of the core half.

Figure 3 shows the two core halves 1, 1' shown in Figure 2.
After polishing the front and rear gap forming surfaces 3 and 4 to a flat and mirror surface, and adding a suitable non-magnetic material such as glass or titanium to a thickness corresponding to the required gap width, the left and right core halves are assembled. 1 and 1' sendust core parts 1a, 1
A' and ferrite core portions 1b and 1b' are combined to face each other to form a magnetic head body 2 using a composite core.Such a head body 2 is clearly visible from the front surface of the head on which the tape slides. As shown, although the head track width part TW is made of Sendust alone, the tape sliding area is reduced to the glass part 7.
It has a structure in which the core has a core thickness of CW including the head gap depth GD, and a winding 9 is applied to the core portion where ferrite is laminated at the lower end than the head gap depth GD.

The magnetic head according to the present invention as described above has improved recording characteristics due to the metal core portion and improved high frequency characteristics due to the composite ferrite portion, thereby providing a magnetic head that is free from saturation and has excellent high frequency characteristics.

In addition, by increasing the front and rear gap forming areas of the core halves by the glass portion, the planar accuracy of the gap forming surfaces is improved, and stress concentration on the sendust core gap surface due to the increase in the gap forming area is achieved. It has been recognized that it has been possible to avoid this problem, achieve a stable gap, and improve head characteristics.
The wear resistance properties are also improved.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is a side view showing a main core and an auxiliary core forming core halves, and FIG. 2 is a perspective view showing a pair of core halves.
FIG. 3 is a perspective view showing an embodiment of the present invention. 1a... Main core, 1b... Auxiliary core, 3... Front gap forming surface, 4... Rear gap forming surface, 7...
...Nonmagnetic material, 8...Ferrite material.

Claims (1)

[Claims for Utility Model Registration] (1) A pair of core halves each having a front gap-forming surface and a rear gap-forming surface are joined together with the front gap-forming surfaces and the rear gap-forming surfaces to form a magnetic head core. In the magnetic head, the core half is made of a material with a high saturation magnetic flux density and has a thickness of a predetermined track width, a main core part near the front gap forming surface is made of a non-magnetic material, and the remaining part is made of a material with an electric ratio. A magnetic head characterized in that it is constructed by joining an auxiliary core made of a magnetic material with high resistance. (2) The magnetic head according to claim 1, wherein the shape of the magnetic material portion of the auxiliary core is gradually tapered toward the front gap forming surface.