JPH05347010A - Magnetic head - Google Patents

Abstract

(57) [Abstract] [Purpose] To simplify the process of assembling the recording / reproducing coil, the recording / reproducing back bar, the erasing coil and the erasing back bar to the flat E-type composite core member, and improve the assembling accuracy. [Structure] The erasing coil 5 wound around a bobbin 4 made of molded resin is mounted on the leg piece 1c of the E-shaped composite core member 1, and the leg piece 1c is attached.
An erasing back bar 6 is attached to the end of c. Bobbin 4
A pin 4b for positioning and fixing the back bar 6 is formed and placed on the flange portion 4a, and the back bar 6 is fixed by caulking the pin 4b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head used in a magnetic disk recording / reproducing apparatus such as a floppy disk apparatus, and more particularly, to an improvement in a core element assembly structure.

[0002]

2. Description of the Related Art In a general floppy disk device, a magnetic head called a tunnel erase head is used. The structure of the main part of a typical magnetic head of this type is shown in FIG. In FIG. 1, reference numeral 1 denotes a composite core member which is the center of the core element of the tunnel erase head. This composite core member 1 has a structure generally called a laminate type, and is configured as a flat E type having three leg pieces 1a, 1b, 1c. As is well known, there is a recording / reproducing gap in the portion connecting the central leg piece 1b and the one leg side leg piece 1a, and in the portion connecting the central leg piece 1b and the other end side leg piece 1c. There are two erase gaps. A ceramic slider is joined so as to sandwich the peripheral portion of the composite core member 1 from both sides, and the ceramic slider is usually attached to a gimbal plate, but the description of the configuration of this portion is omitted in this specification.

Further, as shown in FIG. 1, a recording / reproducing coil 3 wound around a resin molding bobbin 2 is mounted around a leg piece 1a on one end side of an E-shaped composite core member 1, and the leg piece 1a and a central leg are mounted. A recording / reproducing back bar 7 is attached so as to span the ends of the piece 1c. The back bar 7 is made of a prismatic ferromagnetic material and is a yoke component that magnetically connects the ends of the leg pieces 1a and 1b, and is fixed to the leg pieces 1a and 1b with a magnetic adhesive or the like. The magnetic circuit of the recording / reproducing head is constituted by the above elements.

Similarly, an erasing coil 5 wound around a resin molding bobbin 4 is mounted around the other end side leg piece 1c of the E-shaped composite core member 1, and the end portions of the leg piece 1c and the central leg piece 1b are attached. An erasing back bar 6 is arranged between them to form a magnetic circuit of the erasing head. The erasing back bar 6 is a small component formed by bending a ferromagnetic plate into an L shape. One piece of the back bar 6 is joined to the upper end surface of the leg piece 1c and fixed with a magnetic adhesive or the like, and the other piece is attached to the central leg piece 1b. It is arranged so as to face the side surface of the with a proper interval. The reason why the erasing back bar 6 is not directly joined to the central leg piece 1b in this way is to increase the resistance of the magnetic circuit of the erasing head to some extent to obtain desired characteristics.

[0005]

In the conventional magnetic head having the structure shown in FIG. 1, it is very troublesome to attach the erasing back bar 6 to the E-type composite core member 1 during the assembling process. Moreover, there is a problem that it is difficult to increase the accuracy of the mounting position of the back bar 6. In the example of FIG. 1, the L-shaped erasing back bar 6 is positioned by butting against the upper end surface of the leg piece 1c and the flange end surface of the coil bobbin 4, and is fixed with a magnetic adhesive. If the back bar 6 is not firmly positioned by some means until it is done, the back bar 6 will be fixed to the core member 1 in a state of being displaced from the regular position. Therefore, the process of bonding the back bar 6 becomes very troublesome, and if an attempt is made to simplify this process, the displacement of the back bar 6 becomes large and the characteristics of the erasing head deteriorate.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to provide a magnetic head having a structure in which an erasing back bar can be easily and accurately attached to an E-type composite core member. To do.

[0007]

Therefore, in the present invention, E
In a magnetic head having a structure in which an erasing coil with a resin molding bobbin is mounted around a predetermined leg piece of a mold composite core member, and an erasing back bar is attached to the end of the leg piece, a flange portion of the coil bobbin is provided. A protrusion for positioning and fixing the erasing back bar is formed in advance, and the protrusion is caulked to fix the erasing back bar.

[0008]

[Function] The erasing back bar is positioned with respect to the leg of the composite core member by utilizing the projection of the coil bobbin, and the erasing back bar is immediately fixed by caulking the projection with a soldering iron or the like. can do. Even if the final fixing of the back bar is made by the magnetic adhesive, it is not necessary to hold the back bar until the adhesive is hardened.

[0009]

FIG. 2 shows the structure of a magnetic head according to the first embodiment of the present invention. The basic structure is the same as that of the conventional magnetic head described in FIG. 1, and includes a flat E-type composite core member 1 and a bobbin 2 mounted around one end side leg piece 1a of the composite core member 1. Recording and reproducing coil 3,
A recording / reproducing back bar 7 as a yoke attached by a magnetic adhesive so as to be bridged between the ends of the leg piece 1a and the central leg piece 1b of the composite core member 1, and the leg piece on the other end side of the composite core member 1. An erasing coil 5 with a bobbin 4 mounted around 1c and an erasing back bar 6 as a yoke arranged between the ends of the leg piece 1c and the central leg piece 1b are provided.

The erasing back bar 6 is a small part formed by bending a magnetic plate into an L shape, one part of which is joined to the upper end surface of the leg piece 1c, and the other part of which is spaced a predetermined distance from the side surface of the central leg piece 1b. Let's face each other.

The bobbin 4 of the erasing coil 5 is a molded resin component and has two flange portions. Two pins 4b symmetrically positioned on both sides of the leg piece 1c are integrally formed on the flange portion 4a arranged above them. Two
The pin 4b of the book is a protrusion for positioning and fixing the erasing back bar 6. That is, when the erasing back bar 6 is attached to the leg piece 1c of the composite core member 1, the horizontal piece portion of the back bar 6 is fitted between the two pins 4b and abuts on the upper surface of the leg piece 1c. When the back bar 6 is correctly positioned with respect to the leg piece 1c, the tips of the two molded resin pins 4b are heat-squeezed with a jig such as a soldering iron as shown in FIG. The leg piece 1c is fixed by pressing it toward the end face side. The leg piece 1c and the back bar 6 are finally fixed with a magnetic adhesive.
It is possible to temporarily fix the pin 4b in a correct position by caulking the pin 4b at the time of mounting, and it is not necessary to hold the back bar 6 by other means until the adhesive is hardened.

FIG. 3 and FIG. 4 show the essential structure of another embodiment of the present invention. In this embodiment, one positioning and fixing pin 4c located on the extension line of the leg piece 1c is integrally formed on the flange portion 4a of the bobbin, and the pin 4c is fitted to the tip portion of the erasing back bar 6. A matching positioning hole 6a is formed. When the erasing back bar 6 is attached to the leg piece 1c, the hole 6a of the back bar 6 is passed through the pin 4c of the bobbin flange portion 4a. Then, as shown in FIG. 4, the back bar 6 is fixed by caulking the tip portion of the pin 4c penetrating the hole 6a. The hole 6a of the back bar 6 in this embodiment may be a slotted notch 6b as shown in FIG.

As is apparent from the above embodiments, there are various configurations of the positioning and fixing protrusions provided on the flange portion 4a of the bobbin 4 and the corresponding positioning and fixing configuration on the erasing back bar 6 side. If the structure is such that the back bar 6 can be firmly fixed by crimping the protrusion of the bobbin flange portion 4a, this is not only used as a temporary fixing means, but also fixed by a magnetic adhesive is omitted. You can also do it.

Although the magnetic head using the laminated type composite core member has been described in both the conventional example and the embodiment of the present invention, the present invention is not limited to this, and the present invention is also applied to a bulk type tunnel erase head. It can be applied in the same manner and has the same effect as the above.

[0015]

As described above in detail, in the present invention, the erasing coil with the bobbin is attached to the leg of the E-shaped composite core member, and the erasing back bar is attached to the end of the leg. In the structure, a protrusion for positioning and fixing the back bar is formed on the flange portion of the bobbin, and the back bar is fixed by caulking the protrusion. The mounting process is greatly simplified and the mounting position accuracy is improved. In other words, high-performance magnetic heads with uniform characteristics can be mass-produced efficiently.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of a main part of a conventional magnetic head.

FIG. 2 is a perspective view showing the configuration of the main part of the magnetic head according to the first embodiment of the invention.

FIG. 3 is a partially exploded perspective view of a magnetic head according to a second embodiment of the present invention before mounting an erasing back bar.

FIG. 4 is a partial perspective view after mounting the back bar in the embodiment of FIG.

5 is a partial perspective view of a back bar showing a modified example of the embodiment shown in FIGS. 3 and 4. FIG.

[Explanation of symbols]

 1 E-type composite core member 1a, 1b, 1c Leg piece 2 Bobbin 4a Flange portion 4b Positioning and fixing pin 4c Positioning and fixing pin 5 Erasing coil 6 Erasing back bar 6a Positioning and fixing hole 6b Positioning and fixing Notch

Claims (1)

[Claims] 1. A flat E-shaped composite core member, a recording / reproducing coil mounted around one end side leg piece of the composite core member, one end side leg piece of the composite core member and an end of a central leg piece. A recording / reproducing back bar as a yoke mounted so as to be bridged between the parts, an erasing coil mounted around the other end side leg piece of the core member, and the other end side leg piece of the composite core member. A magnetic head having an erasing back bar as a yoke arranged between the ends of the center leg piece and the center leg piece, wherein the erasing coil is wound around a resin molding bobbin and the other end side leg of the composite core member is provided. It is mounted on a piece, and a protrusion for positioning and fixing the erasing back bar is formed on a flange portion of the bobbin, and the erasing back bar is fixed by caulking the protrusion. And a magnetic head.