JPS6275908A - Magnetic head core and its manufacture - Google Patents

Abstract

PURPOSE:To easily assemble the head core without fail by laminating the core piece by the connecting means equipped at its own body. CONSTITUTION:At a core piece 1, an engaging means 2 mutually connected is equipped. By using the means 2, the core piece 1 is laminated, and then, the head core can easily be assembled without fail, the head is rapidly formed and the characteristic of the head such as the reproducing output and the inductance is improved.

Description

[Detailed Description of the Invention] 1. Then, the step of annealing the whole; 1
A magnetic head core 1 characterized by comprising:
manufacturing method.

1 3. Detailed Description of the Invention □ [Technical Field of the Invention] Pipe The present invention relates to a magnetic rad core that has a novel structure and can be assembled with fewer man-hours, and a method for manufacturing the same.

[Technical background of the invention and its problems 1 A magnetic head that writes and reads information by contacting a magnetic medium is one of the extremely important parts of various magnetic recording devices.

This magnetic head has high magnetic permeability and low core loss.

It has one or more built-in head cores made of magnetic material with high maximum magnetic flux density and good wear resistance.

By the way, mallalloy (Ni-Fe based soft magnetic material) is often used as the core material for mass-produced products such as audio equipment. The present invention relates to a case where a material ``1'' which can be plastically worked, such as permalloy, is used for the head core.

Although the head core differs depending on the grade required for the magnetic head, it may consist of a single core or a 0.05
A laminate type material in which a plurality of thin core pieces of about 0.3 mm are laminated is used.

Generally, the former type of head core causes core loss (eddy current loss), so the latter type of laminate type head core is preferred.

Conventionally, this laminate type head core has been manufactured as follows. That is, from a permalloy plate, first, a core piece having the shape as illustrated in the cut-out view in Fig. 3 is punched out, and then the distortion accumulated during processing is removed to obtain the magnetic properties based on Proposition 1. 1 to put out usually 100
Annealing is performed at a temperature of about 0 to 1200°C. Thereafter, a plurality of annealed core pieces are bonded and laminated to form a head core while being subjected to interlayer insulation treatment.

However, in the case of the conventional method described above, the permalloy core pieces soften during annealing and are difficult to handle.
Laminating and gluing small parts one by one requires a great deal of time and man-hours, creating a disadvantageous situation for the artisan.

Especially for magnetic heads such as high-end audio products,
Since the head core used is required to have a relatively large number of IX#J core pieces laminated, the problem described in 1-1 can be said to be an important problem to be solved.

[Objective of the Invention] The object of the present invention is to provide a held core having a structure that can solve the problems described in -1- and significantly reduce the number of man-hours during assembly, and a method for manufacturing the same.

[Summary of the Invention] In the course of intensive research to achieve the above objectives, the present inventors discovered that the problem of increasing the number of core pieces in the conventional held core assembly method was solved by annealing the core pieces and then laminating them. We focused on the fact that the main cause is due to integration, and therefore came up with the idea that these problems could be solved by laminating and then annealing the integrated product. however,
When a stack of core pieces is then annealed, it is disadvantageous if the core pieces separate into pieces again during this annealing process.

On the other hand, it is also possible to fix with epoxy resin like this core piece after annealing, but in that case, the epoxy resin is sintered during the annealing step 11 and the fixing force is lost, so it is meaningless. It is also possible to use a heat-resistant inorganic adhesive, but this bonding process takes a lot of time and is not useful for T-man. For these reasons, the present inventors came up with a method of mechanically fixing each core phase 1f.

That is, the head cores of the present invention are engaged with each other: L
match,. Ya xitsi. 5, ~+71; 1a, 1
- □ has an integrally laminated structure, and the manufacturing method thereof includes a first step of laminating a plurality of magnetic head core pieces each having means for engaging each other with the engaging means interlocking with each other;
1. Second step of applying external force to integrate the whole;
After that, it is characterized by comprising the steps of annealing the entire body.

First, the head core of the present invention is a laminated structure of core pieces which itself is provided with a fastening means. An example of the core piece is shown in FIG. 1 (top view) and FIG. 2 (side view). In the figure, 1 is a core piece made of permalloy, and 2 is a fastening means.

The fastening means shown in the figure is processed into a shape that is depressed on one surface A of the core piece and protrudes on the other surface B. At least one of these fastening means 2 may be formed at any arbitrary position on the core piece. The fastening means can be easily formed by stamping at the same time as punching the core piece from the permalloy plate.

The head core of the present invention is a structure in which a plurality of such core pieces are laminated and integrated with their respective fastening means interlocked. That is, A of one core piece in FIG.
The surface and the B surface of another core piece to be laminated thereon are occlusally Φ-integrated at the respective sinkholes and protrusions.

Note that this fastening means 2 may have any structure as long as it can fasten the core pieces to each other. For example, when punching out the core pieces from a permalloy plate, the ends may be intentionally pressed. For example, the end portion may be formed with four small parts and a convex part that interlock with each other, or an embossing may be added.

In the head core of the present invention, first, a core piece provided with a fastening means as shown in FIGS. 1 and 2 is punched out of a permalloy plate.

The obtained multiple core pieces are interlocked with each fastening means)
H layer. That is, the recessed hole on the A side of the core piece and the small protrusion on the B side of the other core J1 are brought into engagement. At this time, it will be more effective if interlayer insulation is provided by some method.

Then, an external force is applied to the whole. As a result, each core node i
The small protrusion located on the back side was press-fitted into the sinkhole, and the whole unit became one piece! By carrying out these two processes, namely the punching process and the laminating process of each core piece, as a series of operations using the same press machine, great industrial effects can be achieved.

Thereafter, this integrated product is placed in a furnace at a predetermined temperature and subjected to a predetermined heat treatment to remove distortion accumulated in the core pieces. Normally, temperature 800-1200°C 1 hour 0.1-1
Heat treatment is performed for 0 hours.

[Embodiment of the invention] A core piece having the shape shown in FIGS. 1 and 2 was punched out of a permalloy plate (thickness 0.2 m+s) made of 81% Ni-5.5% Mo-0.5% Mn-Fe. processed. The attachment means are
The diameter of the sinkhole on side A is 1 mm (this refers to the maximum diameter of the sinkhole on side A), the depth is 0-3 mm + the diameter of the small protrusion on side B (this refers to the minimum diameter of the protrusion on side B) ) It was a bocchi with a diameter of 0.7mm and a height of 0.3a+m.

Three of these core pieces are stacked together and the total weight is 0.5 ton/
It was pressed with a pressure of -. A head core material having a total thickness of 0.8 mm was obtained. Next, this head core material was heated to 1100° C. in a hydrogen furnace to remove strain.

For comparison, the composition is the same as the above composition, and the first one is made of permalloy plates with thicknesses of 0.2 mm, 0.3 mm, and 0.6 m+a, respectively, except that there is no fastening means.
A core piece having the same shape as that shown in Fig. 2 was punched out.

Each core piece was heated to 1100° C. in a hydrogen furnace to remove strain. This was fixed using an epoxy resin using a conventional method to produce three types of comparative head cores.

Using the obtained four types of head cores, magnetic heads were manufactured according to a conventional method, and the reproduction output and inductance of each magnetic head were measured. The results are shown in the table. Note that the numerical values in the table are shown as relative values, with the value of the head of Comparative Example 1 being 100.

[Effects of the Invention] As is clear from the above explanation, the head core of the present invention has the following effects:
Handling: It can be handled in the same way as a one-piece object, and its characteristics are far superior to those of Comparative Example 3, which is an one-piece object. Moreover, its characteristics are comparable to those of the head core of Comparative Example 1, which is a conventional standard product. Moreover, the manufacturing method does not require the work of laminating small parts after annealing, as is the case with Comparative Examples 1 and 2, so the overall man-hour can be significantly reduced, and its industrial usefulness is improved. is extremely large.

[Brief explanation of drawings]

1 and 2 each show a core piece constituting a core according to the present invention, and FIG. 1 is a plan view thereof. FIG. 2 is a side view thereof. FIG. 3 is a perspective view of a conventional core piece.

Claims (1)

[Scope of Claims] 1. A magnetic head core characterized in that a plurality of magnetic head core pieces each having means for engaging each other are integrally laminated. 2. The magnetic head core according to claim 1, wherein the locking means is at least one interlocking portion formed at a predetermined position of the core piece. 3. A first step of stacking a plurality of magnetic head core pieces each having means for engaging with each other in a state in which the engaging means interlock with each other; a second step of applying an external force to integrate the whole; A method for manufacturing a magnetic head core, comprising: annealing;