JPH067407B2 - Magnetic core - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a magnetic core, and more particularly, to a magnetic recording medium, which is formed by a pair of substantially U-shaped core halves butted against each other via a magnetic gap. The present invention relates to a magnetic core of an induction type magnetic head that is in sliding contact with the recording / reproducing of information.

[Prior Art] A conventional structure of this type of magnetic core and an assembly structure of a magnetic head incorporating the same will be described with reference to FIG.

In FIG. 5, reference numerals 1 and 1 denote core halves, respectively, which are made of high-permeability magnetic material, and are formed into bent portions 2 and 3 in which the upper end portion and the lower end portion are bent in the same direction. The tip surfaces of the bent portions 2 and 3 are butted surfaces 2a and 3
a.

Further, reference numerals 4 and 4 are support halves for supporting the core halves 1 and 1, which are block shapes of a rectangular parallelepiped in which the protrusion 4a is formed along one side, and the protrusion 4a is formed. Slot 4b from the middle of the side surface to the protruding portion 4a
Are formed.

As shown in the figure, each of the core halves 1 and 1 is fitted into the long grooves 4b and 4b of the support halves 4 and 4 and fixed by adhesion or the like.

Next, after finishing the abutting surfaces 2a and 3a by grinding, a pair of the assembly of the core half body 1 and the support half body 2 is attached to the abutting surface 2 of the respective core half bodies 1 and 1.
They are abutted at a and 3a and joined by adhesion or the like.

At the time of this butting, the bent portions 3, 3 of the core halves 1, 1
A terminal conductor 6 to which the coil 5 is wound and which is connected to the terminal
The bobbin 7 in which is planted is fitted.

As described above, the core halves 1 and 1 and the support halves 4 and 4
A magnetic head element body 8 which is an assembly of the bobbin 7 and the bobbin 7 is obtained.

After the magnetic head element body 8 is fitted in the shield case indicated by the reference numeral 9, the magnetic head element body 8 is fixed by filling the shield case 9 with a fixing material such as resin to complete the magnetic head.

However, according to the above configuration, the assembly of the core halves 1 and 1 and the bobbin 7 (hereinafter referred to as the core assembly) is 2
Since it is completed in the state where it is assembled in the individual support halves 4 and 4, if the core assembly is found to be defective by the inspection after completion, even the two support halves that accompany the core assembly Must be discarded. This waste increases the cost.

Further, according to the above configuration, the abutting surface 2 of the core half body 1
Grinding for finishing a and 3a is performed in a state where the core half body 1 is incorporated in the support half body 4, so that the entire size becomes large and the number of pieces that can be ground at one time is limited. That is, the efficiency of this grinding process was poor, and the cost was increased accordingly.

Therefore, the applicant of the present application previously proposed, as a magnetic core structure for solving such a problem, a plurality of high-permeability magnetic material thin plates having a substantially U-shape and at least one high-permeability magnetic thin plate having a substantially U-shape. Is laminated to form a core half body, and this core half body is abutted against another core half body having a similar configuration, and the intermediate protruding portions of the Y-shaped core half bodies are joined and joined together. Proposed (JP-A-59-182505).

[Problems to be Solved by the Invention] According to the above-mentioned structure proposed by the applicant of the present invention, the joint strength of the core halves is increased due to the jointing of the protrusions, so that the core halves are not bonded to each other alone. It becomes possible to butt and join. Therefore, finishing grinding of the abutting surfaces of the core halves can be performed by the core halves alone, and can be performed many times at a time. In addition, since the support half can be incorporated into the support half after joining, the support half is not wasted due to a defect in the magnetic core. Furthermore, since the bonding strength is high, only one support half is required for each magnetic core, and the number of parts of the magnetic head can be reduced.

However, in this structure, the entire Y-shaped thin plate is made of a high-permeability magnetic material, so that the magnetic circuit of the magnetic core is magnetically coupled in the intermediate region of the front and rear magnetic gaps through the protrusion, and this coupling is magnetic. Affects core characteristics. This effect is very delicate due to the small cross-sectional area of the protruding portion, and has not been a practical problem because the magnetic core characteristics have not been so severely demanded in the past. However, the recent demand for higher performance of magnetic cores cannot be ignored.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the magnetic core according to the present invention has a plurality of high-permeability magnetic material thin plates having a substantially U-shape and a protrusion in the middle. In the vicinity of the sliding contact portion with the magnetic recording medium, which is generally Y-shaped or comb-shaped, is made of a high-permeability magnetic material,
Of the remaining parts, at least the projecting part is laminated with at least one thin plate made of a non-magnetic material to form a core half body, and one pair of the core half body is butt-joined to each end part and the projecting part. The adopted structure is adopted.

[Operation] According to the structure described above, the joint strength between the core halves can be increased by joining not only the both ends but also the protrusion. Further, in this case, since the protrusion is made of a non-magnetic material, magnetic coupling of the magnetic circuit of the magnetic core via the protrusion does not occur.

Embodiments Embodiments of the present invention will be described in detail below with reference to FIGS. 1 to 4.

FIG. 1 is a perspective view of a core half for explaining the structure of the magnetic core according to the present embodiment.

As shown in the figure, a pair of core halves 1 forming a magnetic core.
Each of 0 and 10 is formed by laminating a predetermined number (five in this case) of core thin plates 11 and one joining reinforcing thin plate 12 via an insulating adhesive material.

The outer shape of the core thin plate 11 is formed in a substantially U shape,
Both ends are bent in the same direction, and the whole is made of a high magnetic susceptibility magnetic material such as permalloy.

As shown in FIG. 2 (a), the joint reinforcing thin plate 12 has a shape corresponding to that of the core thin plate 11 as well as both end portions 12a and 12b.
A protrusion 12c is formed at an intermediate portion between the both ends 12a and 12b so as to protrude in substantially the same direction, and has a substantially Y-shape. The end surfaces of the both end portions 12a and 12b and the protruding portion 12c are substantially aligned with each other.

Then, the joint reinforcing thin film 12 is formed by punching a composite metal plate 13 into a Y-shape by pressing or the like as shown in FIG. 2 (b). The composite metal plate 13 is formed by combining a non-magnetic material portion 14 such as stainless steel shown by diagonal lines and a high-permeability magnetic material portion 15 such as permalloy into one piece. Therefore, in the joining reinforcing thin plate 12, the end portion 12a of the recording medium which is in sliding contact with the magnetic tape is made of a high magnetic permeability magnetic material, and the remaining portion is made of a non-magnetic material.

After finishing grinding the abutting surfaces 10a, 10b at both ends of the pair of core halves 10, 10 formed by laminating the joining reinforcing thin plate 12 and the core thin plate 11, the core half 10, The abutting surfaces 10a and 10b of 10 are abutted and joined to each other via a magnetic gap, and at the same time, the single surfaces of the protruding portions 12c are abutted and joined by welding or the like to obtain a magnetic core.

Further, the bobbin 7 described above in the conventional example is fitted to the ends of the core halves 10 on the side of the abutting surface 10b at the time of the above-mentioned butting, and the core assembly shown in FIG. 3 is obtained by the above joining. In addition, a portion indicated by reference numeral 16 in FIG.
It is a welded part of each other.

Further, the core assembly is fitted to the support half body 4 described above to obtain the magnetic head body 8 shown in FIG. 4, and the magnetic head body 8 is fitted and fixed to the shield case in the same manner as described above. The magnetic head is completed.

By the way, according to the magnetic core of the present embodiment, the abutting surface 10
Since the joining is carried out at three points a, 10b and the projecting portion 12c and the joining at the projecting portion 12c is performed by welding, a much greater joining strength than the conventional one can be obtained.

Therefore, as described above, since the core halves 10 can be joined in a state where the individual halves of the core halves are joined together, the efficiency of the processing of the core halves can be improved and the support can be provided as in the case of the structure proposed by the applicant. It is possible to eliminate waste of half body and reduce the number of parts.

Further, according to the core of the present embodiment, since the protrusion 12c is made of a non-magnetic material, the magnetic circuit of the core is not coupled via the protrusion 12c, and the joining structure via the protrusion 12c has the characteristic of the magnetic core. It has no effect on.

In addition, the protrusion 12c is formed of a non-magnetic material so that the protrusion 1
The range of material selection of 2c is expanded, a material having a larger welding strength can be selected, and the joining strength between the core halves can be further increased. As non-magnetic materials having high welding strength, there are nickel silver and the like in addition to stainless steel.

In the above structure, the joint reinforcing thin film 12 has a substantially Y-shape and has one protruding portion 12c, but it may be formed in a substantially comb shape to form a plurality of protruding portions 12c.

Further, in the joining reinforcing thin plate 12, other portions than the end portion 12a other than the protruding portion 12c may be formed of a high magnetic permeability magnetic material.

Further, a plurality of joining reinforcing thin plates 12 may be used for one core half.

[Effect] As is apparent from the above invention, according to the magnetic core of the present invention, a plurality of thin sheets of high-permeability magnetic material having a substantially U-shape and a protruding portion in the middle are provided, and a substantially Y-shape or a comb-shape. A core half is formed by laminating at least one thin plate which has a shape and has a high magnetic permeability magnetic material in the vicinity of a sliding contact portion with a magnetic recording medium and at least the protrusion of the remaining portion is a non-magnetic material. , A structure in which one pair of the core halves are butt-joined to both ends and the protrusions is used, and since the joining strength of the core halves can be made much larger than conventional, In addition to improving productivity, waste can be eliminated in the manufacturing process of the magnetic head and the number of parts can be reduced by using this, and the cost of the entire magnetic head can be reduced. Furthermore, since the joining via the above-mentioned protruding portion does not affect the characteristics of the magnetic core, excellent characteristics can be obtained, and it is possible to meet the requirements for higher performance and higher reliability of bacteria.

[Brief description of drawings]

FIG. 1 is a perspective view showing a structure of a core half of a magnetic core according to an embodiment of the present invention, FIG. 2 (a) is a perspective view of a joining reinforcing thin plate in FIG. 1, and FIG. 2 (b) is Illustration of the formation of the same thin plate,
3 is a perspective view of a core assembly composed of the core halves of FIG. 1, FIG. 4 is a perspective view of a magnetic head assembly composed of the core halves of FIG. 3, and FIG. It is an explanatory view of a structure of a core and an assembling structure of a magnetic head by the structure. 10 ... Core half body, 11 ... Core thin plate 12 ... Bonding reinforcing thin plate 12a, 12b ... End part 12c ... Projection part, 13 ... Composite metal plate 14 ... Non-magnetic material part, 15 ... High Permeability Magnetic material part

Claims (1)

[Claims] 1. A high magnetic permeability in the vicinity of a sliding contact portion with a magnetic recording medium having a plurality of thin sheets of magnetic material having a substantially U-shape and a protrusion in the middle and having a substantially Y-shape or a comb shape. A core half is formed by laminating at least one thin plate made of a magnetic material and at least the projecting part of which is a non-magnetic material, and a pair of the core half is formed on both ends and the projecting part. A magnetic core of an inductive magnetic head, which is formed by butt-joining each other.