JPS5857610A - Magnetic head - Google Patents

Abstract

PURPOSE:To keep the relative position between a magnetic head material body and a tape guide at a high level of precision, by unifying and sealing the head material body and the tape guide with the synthetic resin. CONSTITUTION:A magnetic head material body 9 contains a pair of magnetic cores 10 and 10 butted to each other via a spacer 11 and a terminal stage 13 molded with a terminal conductor 12 in a body and fixed at the rear edge part of the material body 9. The stage 13 is formed into a cylinder to double a coil bobbin and wound with a coil 14. The projected parts 15a and 15a are formed at the tip of a tape guide 15 to guide a tape. Both material body 9 and guide 15 are positioned into a metallic mold and fixed there, and then the synthetic resin is filled into the mold to join the material body 9 and the guide 15 together. At the same time, the area of a holder 16 of the magnetic head is unified with the material body 9 into a prescribed form by means of the resin which is used to seal the guide 15. In such way, a magnetic head 17 is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic spatula mill, and more particularly to a magnetic head whose entire magnetic head is integrally C-molded from synthetic resin C-molded.

Conventionally, magnetic heads have been known in which a magnetic head element is sealed and integrated into a synthetic resin.

The structure of a conventional magnetic head employing such a structure is shown in FIGS. 1 to 3.

In the conventional structure C2 shown in FIG.
This figure shows a structure in which they are fitted together and filled with resin to integrate them. As shown in FIG. A terminal block 5 having a terminal conductor 6 molded from an insulating resin or the like is attached, and the opening 1 of the holder 1 is stacked with a plate spring 7 having a V-shaped cross section for positioning.
After fitting from A to predetermined position C2, a structure is adopted in which synthetic resin is filled and fixed by integrally sealing.
The resin 1-, which is filled and sealed after fitting, is usually
Epoxy resins have been used, but the use of epoxy resins has several drawbacks, such as the following two points.

■) Molding temperature is high at 130° to 170°C.

2) The molding shrinkage rate is as high as 02 to 1.0%.

3) Since the molding shrinkage rate of the epoxy resin is large, the stress applied to the sealed core material is also large, reducing the magnetic permeability of the core material and deteriorating the electrical characteristics of the magnetic head.

4) The material cost of epoxy resin is high.

On the other hand, in the conventional structure C shown in FIGS. 2 and 3,
Figure 1 (Similar to duality (= preliminarily integral 1-
The molded holder 1C-tape guide pin 8°8 is fixed by press-fitting or using an adhesive, etc. After that, the magnetic head element is fitted into the holder 1, and then synthetic resin is filled and integrated. It adopts a two-forming structure (3).

However, if such a structure is adopted, the dimensional relationship between the reference surface for attaching the magnetic core of holder 1 and the part for attaching the tape guide pins 8, 8, shown in FIG. If such a structure is adopted, when the magnetic head element is fitted to the holder 1, dust or synthetic resin shavings will be removed from the reference surface A for positioning the magnetic core of the holder 1. etc. are easily pinched, and the mounting of the magnetic core and tape guide pins 8, 8 is prone to positional accuracy (-variation).

In addition, since synthetic resin is used to seal the magnetic head element, as shown in Fig. This part has disadvantages such as the generation of bubbles, and the resin in a fluid state flows out of the holder from between the magnetic core and the reference surface, causing the resin to stick to the tape guide 8.8. However, if this is not removed, there are drawbacks such as troubles in running the tape.

The present invention has been made in order to eliminate the above-mentioned drawbacks of the conventional technology (4). The object of the present invention is to provide a magnetic head configured such that the relative dimensional position between the magnetic core and the magnetic core can be determined with high accuracy.

In order to achieve the above objects in the present invention (2), (1) the magnetic head element is integrally sealed (2) a synthetic resin with an extremely low shrinkage rate and an extremely low water absorption rate is used as the synthetic resin; 2. The holder also has a structure in which it is molded into a predetermined shape by a synthetic resin C2 that seals the magnetic head element body.

Hereinafter, the invention will be described in detail based on the embodiments shown in the drawings.

FIG. 4 illustrates a magnetic head element 9. This magnetic head element 9 is made up of a pair of left and right magnetic cores 10.10 butted against each other with a spacer 11 in between. - is fixed with a terminal block 13 in which a terminal conductor 12 is integrally molded.

These terminal blocks 13, 13 are integrated, and there is a cylindrical body between them that also serves as a coil bobbin, and the coil 14 is wound around this coil bobbin (not shown).

Figure 5 shows the tape guide.
5 is formed into a flat plate shape (-), and the tip C2 is formed with protrusions 15a, 15a for pinching and guiding the tape.

The magnetic head element 9 and tape guide 15 formed as described above are prepared, and they are positioned and fixed in a mold (not shown), and then filled with synthetic resin and integrated. Then, as shown in FIG. 6C, the holder 16 of the magnetic head is also integrally molded into a predetermined shape with resin for sealing the magnetic head body and the tape guide to obtain the magnetic head 17.

By the way, in addition to sealing the magnetic head assembly and tape guide, the synthetic resin for molding the holder 16 is not epoxy resin, which has the disadvantages mentioned above, but polyester resin or A thermosetting synthetic resin containing diallyl phthalate resin as the main ingredient and reinforcing agents, fillers, etc. is used. These resins have a molding shrinkage rate of 0.1 inch or less and a water absorption rate of 0.2% or less.

When the core element and tape guide are integrally molded using such a synthetic resin, (1) the molding temperature is as low as 90 DEG to 140 DEG C.;

2) The molding shrinkage rate is below 01%.

3) Since the molding shrinkage rate is low, the stress applied to the sealed core body is small, the magnetic permeability of the core does not decrease, and the characteristics of the core material can be utilized as they are as the electrical characteristics of the magnetic head. .

4) The abrasive cost of resin is approximately half or less compared to epoxy resin (-).

5) A manufacturing method such as forming the holder, magnetic head element, tape guide, etc. separately, fitting them to the holder C, and then filling them with resin is not adopted, so there is no flow. The resin in the state does not flow out of the holder or adhere to the tape guide, etc.

6) Since the tape guide is also integrally C-molded from the synthetic resin that seals the magnetic head element, the mounting of the magnetic core requires extremely high precision ( −Can be done.

7) The holder and the magnetic head element are not formed separately, but are molded into a single piece of synthetic resin. Dust, synthetic resin debris, etc. are not caught between the magnetic core and the magnetic head, and variations in relative positional accuracy between the magnetic head element and the tape guide do not occur.

In addition, as shown in FIG.
6a is formed, and after molding (second step, this groove 16a
A structure may be adopted in which the tape guide 15 is fitted and fixed with an adhesive or the like.

Even if such a structure is adopted, unlike the conventional structure in which the holder part is molded separately and the magnetic head element is sealed in this holder, the entire magnetic head is placed in the holder. (Including the corresponding parts (7)) Since they are integrally molded from the same resin, the dimensional accuracy of the magnetic head element and the groove in which the tape guide fits is maintained at high precision, and the tape guide 15 can be installed with high precision.

As is clear from the above description, according to the present invention (C), the magnetic head element and tape guide are fixed in a mold and filled with synthetic resin to integrate the magnetic head element, body, and tape guide. Since the structure is adopted in which both the sealing and the external shape of the magnetic head are integrally C-molded, the relative positional relationship between the magnetic head element and the tape guide can be maintained with high precision. At the same time, the structure uses a synthetic resin that has an extremely low mold shrinkage rate and an extremely low water absorption rate as an integrated synthetic resin, so the generation of internal stress when the resin contracts (2) is significantly reduced. Therefore, it is possible to obtain a low-cost magnetic head that does not reduce the magnetic permeability of the core material or cause deterioration of the electrical characteristics of the magnetic head.

[Brief explanation of the drawing]

Figure 1 is an exploded perspective view explaining the conventional structure, and Figures 2 (8) and 3 are perspective views of the holder and the assembled state of the magnetic and rad element body, explaining other conventional structures. , FIG. 4 and the following illustrate one embodiment of the present invention. FIG. 4 is a perspective view of a magnetic head element, and 9th...Magnetic head element 10...Magnetic core 11...Spacer
12...Terminal conductor 13...Terminal block
14... Coil 15... Tape guide 16.
...Holder 17...Magnetic head.

Claims (1)

[Scope of Claims] (1) A magnetic head characterized in that at least a magnetic head element is sealed in a synthetic resin, and the sealed synthetic resin is molded into a predetermined shape. (2) A portion of the magnetic head made of synthetic resin formed into a predetermined shape (- indicates a groove portion for attaching a tape guide); Head. (3) Claim 1, characterized in that the tape guide and the magnetic head element are sealed with a synthetic resin (two-ply), and the sealed synthetic resin is molded into a predetermined shape (-). or the magnetic head described in item 2. (4) The synthetic resin for sealing the magnetic head element etc. is mainly made of polyester resin or diallyl phthalate resin, and is molded and shrunk with a thermosetting synthetic resin consisting of a reinforcing agent, filler, etc. A magnetic head according to any one of claims 1 to 3, characterized in that a magnetic head having a water absorption rate of 0.01% or less and a water absorption rate of 0.2% or less is used.