JPS63175210A - Magnetic head - Google Patents

Abstract

PURPOSE:To prevent deterioration of the magnetic characteristics of a magnetic circuit by joining the entire side faces of the 1st and 2nd cores opposite to the sliders to one of both sliders and at the same time using an elastic member unified with a coil bobbin to fixing with pressure a 3rd core to both 1st and 2nd cores. CONSTITUTION:The entire side faces of 1st cores 2a and 4a and 2nd cores 2b and 4b opposite to sliders 7 and 8 are joined to one of both sliders. At the same time, the back cores 15 and 16 are fixed with pressure to those cores 2a-4b via an elastic member plastics, etc., unified with coil bobbins 9 and 12. Therefore, the joined area is maximized as much as possible to one of both sliders of said 1st and 2nd cores and a high degree of joining strength is obtained. In addition, the cores 2a-4b are totally reinforced by means of the sliders 7 and 8 and furthermore no back gap is produced among those cores 2a-4b and back cores 15 and 16. Thus both cores 15 and 16 are fixed to each other with adhesion. Then the deterioration of the magnetic characteristics can be avoided for the cores.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a magnetic head that records, reproduces, or erases information by slidingly contacting a magnetic circuit (magnetic core) with a magnetic recording medium. A coil bobbin is fitted into a magnetic circuit consisting of first and second cores joined together through a third core that connects both cores, and a pair of coil bobbins is slidably contacted with the circuit and a magnetic recording medium on both sides of the magnetic circuit. This is related to my&head which is made by joining the sliders of .

[Prior Art] FIGS. 6 to 8 illustrate the conventional structure of a head of this type used in a floppy disk drive device for recording and reproducing information on a floppy disk as a magnetic recording medium.

In FIG. 6 showing the structure of the magnetic head body, reference numeral 1 denotes a core assembly, which includes a magnetic circuit for recording and reproduction (so-called magnetic core, hereinafter referred to as recording and reproduction core) 2, and an eraser for performing so-called tunnel erasure. It is constructed as a combined body in which two magnetic circuits (also a magnetic core, hereinafter referred to as an erasing core) 4 are joined via a spacing plate 6.

The recording/reproducing core 2 has a T-shaped first core 2a and a T-shaped second core 2b joined to each other via a recording/reproducing gap 3, and further has a second T-shaped core 2a and a second T-shaped core 2b connected to each other at the rear ends of the cores 2a and 2b. It is constructed by joining the back core 15 which is the core of No. 3.

Similarly, the erasing core 4 is connected to a T-shaped first core 4a and a T-shaped second core 4b via an erasing gap 5.5'.
are joined together, and a back core 16, which is a third core, is joined to the rear end portions of the cores 4a and 4b.

However, before joining the respective back cores 15.16, the recording/reproducing core 2 and the erasing core 4 are connected to each other via a spacing plate 6 as a core assembly 1, and non-magnetic sliders 7.8 are bonded to both sides of the core assembly 1. Joined by welding etc.

The slider 7.8 is in sliding contact with a magnetic disk (not shown) together with both cores 2, 4 to stabilize the sliding contact between both cores 2, 4 and protect both cores 2, 4, and is made of ceramics or the like. It has notches 7b and 8b, and is formed into a block shape with an L-shaped cross section. and slider 7
．． 8, the side surface of the upper end in the figure that is not cut out on the side surface facing the core assembly 1 is a joint surface 7a,
8a, each of which is connected to both sides of the upper end of the core assembly l.

After this joining, the cores 2a and 4a of the core assembly l
A coil pobbin 9 around which a recording/reproducing coil 10 is wound and a coil pobbin 12 around which an erasing coil 13 is wound are fitted into each of the core 2a of the core assembly 1.

A seventh
A magnetic head main body 18 shown in FIGS. 8 and 8 is constructed. The coil pobbins 9 and 12 have a structure in which flanges 9b and 12b for regulating the winding width of the coil 10.13 are formed at both ends of a rectangular cylindrical main body having holes 9a and 12a, respectively.

As shown in FIGS. 7 and 8, the magnetic head body 1
8 is positioned and fixed on a support plate 19 made of stainless steel or phosphor bronze, a flexible printed circuit board 20 for leading out an external circuit is connected to the support plate 19, and the coil terminals 10a,
13a to the connecting portion 20a of the same printed circuit board 20.
A magnetic head 21 is configured by connecting to the magnetic head 21.

The magnetic head 21 configured in this way is
In a disk drive device (not shown), a support plate 19 is fixedly attached to a head carriage, and as shown in FIGS. Recording and playback are performed by sliding contact.

In recent years, disk drive devices have been placed in close proximity to equipment that generates high-frequency noise, such as power supplies and displays, due to the miniaturization and increased density of computer systems that use the disk drive devices. For this reason, countermeasures against electromagnetic noise in the magnetic head 21 are required, and as shown in FIGS.
Although not shown in the figure, a shield member called a shield ring that shields electromagnetic noise is attached to the magnetic head main body 18.
It is often placed around the

[Problems to be solved by the invention] However, in the structure shown in FIGS. 6 to 8, the slider 7
．． Coil pobbin 9 on the side opposite to core assembly 1 of 8
, 12 are formed to avoid the joint surface 7a.

The area of 8a becomes extremely small. On both sides of the core assembly 1 facing the slider 7.8, only the upper end is joined.

For this reason, the bonding strength between the coassembly l and the slider 7.8 becomes weak, and this also weakens the bonding strength between the cores 2a and 4a.
Since the head is easily damaged, there is a problem in that the yield in manufacturing the head is lowered. Especially from the back core 1
When joining 5.16 by adhesive, cores 2a, 2b,
4a and 4b are easily damaged.

In addition, in such a structure, it is necessary to uniformly and firmly fix the back cores 15 and 16 to the cores 2a, 2b, 4a, and 4b, but when the back cores 15 and 16 are bonded by adhesive, the adhesive By back core 15.16 and core 2a, 2b.

A pack gap is created between cores 2.4a and 4b.
This results in deterioration of the magnetic properties of 4.

As a countermeasure against this problem, a structure has been proposed in which the back cores 15 and 16 are pressed against the cores 2a, 2b, 4a, and 4b using springs to hold and fix them. However, even with this structure, when attaching the spring, due to the weak bonding strength mentioned above, the core 2a
, 2b, 4a, and 4b are easily damaged.

Furthermore, when attaching the shield ring of the shield member described above to the magnetic head main body 18, there is also a problem of securely fixing the shield ring so that it does not fall off.

[Means for Solving the Problems] In order to solve the above-mentioned problems, according to the present invention, from the first and second cores joined through the magnetic gap and the third core connecting the two cores, In the magnetic head, a coil bobbin is fitted into a magnetic circuit, and a pair of sliders which are in sliding contact with the circuit and the magnetic recording medium are bonded to both sides of the magnetic circuit.
A structure is adopted in which the entire surface of the side surface facing the slider of the core is joined, and the third core is pressed and fixed to the first and second cores by an elastic member provided integrally with the coil bobbin. .

[Function] According to such a structure, the bonding area of the first and second cores to the one slider is maximized as possible, and high bonding strength can be obtained. The first and second cores are entirely reinforced by the slider, and damage to both cores, which is particularly likely to occur when the third core is fixed to both cores, can be prevented. In addition, since the third core is fixed to the coil bobbin by pressure welding using an integrated elastic member, there is no pack gap between the first and second cores and the third core, which is the case when the third core is bonded. The core can be tightly fixed.

[Example] The details of one embodiment of the present invention will be explained below.

1 to 3 illustrate the structure of a magnetic head for a floppy disk drive device of the same type as the conventional example described above as an embodiment of the present invention. In these figures, parts corresponding to those in FIGS. 6 to 8 of the conventional example are designated by the same reference numerals.

In this embodiment, in the structure of the magnetic head main body shown in FIG.
In order to join the back cores 15 and 16 to the cores 2a, 2b and 4a, 4b and fix them by pressure, a structure different from the conventional example is adopted as follows.

That is, first, each of the coil bobbins 9 and 12 shall be formed from a material having appropriate elasticity such as plastic, and a back core 15, 16, a core 2a, and a back core 15, 16, respectively.
As an elastic member that elastically presses 2b, 4a, and 4b,
Both flanges 9b, 9b and 12b, extension portions 9c, 9c and 12 formed integrally by extending one end side of 12b.
C112c is provided. The tips of the extensions 9c and 12c are bent outward at right angles as bent portions 9d and 12d, and a protrusion 9e having a triangular cross section is provided at the center of the back of each of the bent portions 9d and 12d.

12e is formed.

The coil bobbins 9 and 12 are connected to the back cores 15 and 15 of the core assembly l, respectively, as shown by arrows A and A' in FIG.
．． 16 and core 2a.

2b and between cores 4a and 4b, respectively, s, s
It shall be inserted into '6.

For this reason, the cores 2a and 4a are formed in an L-shape so that the winding width of the coil bobbins 9 and 12 can be made as wide as possible, and the back cores 15 and 16 are accordingly formed longer than in the conventional example.

In addition, the slider 7 has a cross-sectional shape and dimensions that almost correspond to the core assembly l before the back core 15 and 16 are joined,
The slider 7 is formed into a block shape with a figure 8 cross section, and relief grooves 7c and 7d for avoiding the coil bobbins 9 and 12 are formed through the slider 7 in the thickness direction. The joint surface 7a facing and joining the core assembly 1 is formed into a substantially figure 8 shape and a continuous plane over its entire surface, corresponding to the side surface of the core assembly 1 facing the joint surface 7a.

The other slider 8 is formed into a block shape as shown in the figure, and has a notch 8b on the side facing the core assembly l for avoiding the pack cores 15 and 16.
, and a relief 18c for avoiding the coil bobbins 9 and 12.

8d is formed to penetrate through the slider 8 in the thickness direction. Further, the side surface of the upper end portion of the slider 8 facing the core assembly 1, which is left cut out, is formed as a joint surface 8a with the core assembly 1, as in the conventional example.

When assembling the magnetic head main body 18 with the structure of each member as described above, first the core assembly l with the back cores 15 and 16 not fixed is joined to the joint surface 7a of the slider 7. In this case, the entire surface of the side surface of the core assembly l facing the slider 7 (excluding the back core 15° and 16 portions) is joined to the joining surface 7a by the above-described structure.

Next, the joint surface 8a of the slider 8 is joined to the upper side surface of the core assembly 1 on the side opposite to the slider 7.

Next, after inserting the back cores 15.16 into the holes 9&, 12a of the coil bobbins 9, 1z as shown by A and A', the coil bobbins 9.12 are inserted into the slider 7 as shown in FIGS. .8 relief grooves 7c, 7d, notch portion 8b and core 2a.

A magnetic head main body 18 is constructed by fitting into the space between zb and between 4a and 4b. In this case, coil bobbin 9
．． Each of the twelve extension parts 9c and 12c has a bent part 9d.
, slider 7 and cores 2a, 2b or slider 7 and cores 4a, 4b are sandwiched between 12d and back cores 15 and 16, and fitted into clearance grooves 7c and 7d, back cores 15 and 16 and coil bobbins 9 and 16. The distance between the 12 protrusions 9e to 12e is the same as that between the slider 7 and the core 2a.
, 2b to 9a are slightly smaller than the total thickness of 4a, 4b. Therefore, the above-mentioned slider 7 and cores 2a, 2b to 4a.

4b is inserted by bending the extension parts 9c, 12c slightly inward, bending the bent parts 9d, 12d forward, and press-fitting them.

The bent portion 9d is elastically deformed by such press-fitting.

The extension portions 9c and 12c including the extension portion 12d press against the slider 7 via the protrusions 9e and 12e with elastic force to return to their original shape, and the back core 15.16 is connected to the core 2a, 2b or 4a via the slider 7.

4b, and the back cores 15 and 16 are held and fixed.

Thereafter, it is fixed to a support plate (not shown) of the magnetic head main body 18 in the same manner as in the conventional example shown in FIGS. 7 and 8.

The magnetic head of this embodiment is constructed by connecting a printed circuit board (not shown).

According to this embodiment as described above, the back cores 15 and 16 are arranged on the side surface of the core assembly 1 facing the slider 7.
That is, the entire surface of the coil bobbin 9° 12 except for the fitting portion is joined to the joint surface 7a of the slider 7. Therefore, the bonding area becomes significantly larger than that of the conventional example, so that the core assembly 1 is bonded to the slider 7 with high strength.

The first and second cores 2a, 2b, 4a, 4b are sliders 7
The cores 2a and 2b are reinforced as a whole, which is particularly likely to occur when fixing the back cores 15 and 16.
, 4a, 4b can be prevented from being damaged, and the yield in manufacturing the magnetic head can be improved.

Further, according to this embodiment, the back core 15.
16 is fixed on the cores 2a, 2b or 4a, 4b, and is not adhesively used as in the conventional example, so an adhesive pack is used between the back core 15.16 and the cores 2a, 2b, 4a, 4b. The back cores 15 and 16 can be fixed in close contact without any gaps, and deterioration of the magnetic properties of the recording/reproducing core 2 and the erasing core 4 due to the pack gap can be prevented.

Moreover, since the extension parts 9c and 12c are integrated with the coil bobbin 9.degree. 12, there is no need to increase the number of parts for the fixing structure of the back core 15, 16, and the fixing can be carried out at low cost.

By the way, it goes without saying that the structure of the coil bobbins 9 and 12 is not limited to the one described above.
A possible structure is as shown in the figure.

The coil bobbin 9 (12) in FIG. 4 differs from the above in that a notch groove 9f is formed in the center of the extension 9C, and the extension 9C is divided into upper and lower halves. A hemispherical protrusion 9e is provided at the center of the back surface of each of the bent portions 9d and 9d at the bisected tip.

9e is formed.

According to such a structure, the extension portion 9c of the coil bobbin 9
, 9c, each of which is in pressure contact with the slider 7.
Since two of e and 9e are provided independently, a more stable pressure contact state can be achieved, and the back core can be held and fixed more stably.

On the other hand, FIG. 5 shows another embodiment of the coil bobbin 9.12, which has the function of fixing a shield ring that shields the magnetic head body 18 mentioned above from external noise (mainly high frequency noise). .

In FIG. 5, a shield ring 22 is made of a high magnetic permeability material, a high conductivity material, or a combination of both materials, and is formed into a rectangular tube shape corresponding to the outer shape of the magnetic head main body 18, for example. The shield ring 22 is fitted around the magnetic head main body 18 so as to surround it as shown.

In addition to the structure common to FIGS. 1 to 3, the coil bobbin 9.12 has cylindrical convex portions 9g, 12g formed on the front surface of the bent portions 9d, 12d (12d not shown) on one side. It is.

The shield ring 22 is positioned and fixed by engaging the convex portions 9g and 12g with holes 22a and 22b formed at corresponding positions in the shield ring 22, respectively.

Note that even if the convex portions 9g and 12g are not formed, the holes 22a,
22b respectively projecting from the slider 7, a bent portion 9d;
12d, and the shield ring 22 may be fixed by engaging the bent portions 9cl and 12d with each of the long holes.

In this way, the coil bobbin 9.12 and the shield ring 22 are engaged with each other, and the shield ring 22 can be securely fixed, and the shield ring 22 can be prevented from falling off.

In addition, in the structure shown in Fig. 5, the Koitare bobbin 9.12
are made of thermoplastic resin, and the convex portions 9g, 12
g is made longer, and the protrusions 9g and 12g are made into holes 22.
The shield ring 22 can also be fixed by heating and deforming the outwardly protruding portion of the shield ring 22 after engaging with the shield rings 22a and 22b. In this case, the shield ring 22 can be fixed more reliably than when the above engagement is used alone.

[Effects of the Invention] As is clear from the above description, according to the present invention, a magnetic circuit comprising first and second cores joined through a magnetic gap, and a third core connecting both cores. In the magnetic head, a coil bobbin is fitted into the magnetic head, and a pair of sliders which are in sliding contact with the circuit and the magnetic recording medium are bonded to both sides of the magnetic circuit.
A structure is adopted in which the entire side surface of the core facing the slider is joined, and the third core is pressed and fixed to the first and second cores by an elastic member provided integrally with the coil bobbin. , the bonding strength of the first and second cores to the slider can be increased, and the bonding strength of the first and second cores to the slider can be increased.
It is possible to prevent damage to the core of the head and improve the manufacturing yield of the head. Further, it is possible to prevent a pack gap from occurring between the a81, the second core, and the third core, and it is possible to obtain an excellent effect that deterioration of the magnetic characteristics of the magnetic circuit due to the pack gap can be prevented.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing the structure of the magnetic head main body of a magnetic head according to an embodiment of the present invention, and FIGS. 2 and 3 are respectively a perspective view and a bottom view of the magnetic head main body of FIG. 1 in an assembled state. , FIG. 4 is a perspective view showing another embodiment of the coil bobbin, FIG. 5 is a perspective view showing a shield ring fixing structure using the coil bobbin, FIG. 6 is an exploded perspective view of the magnetic head main body of a conventional magnetic head, and FIG. 8 are a perspective view and a sectional view, respectively, of a conventional magnetic head in an assembled state. 1... Core assembly 2... Magnetic reproducing core 2a,
4a...First core 2b, 4b...Second core 4...Erase core 7.8...Slider 9.1
2...Coil bobbin 9c, 12c...Extension portion 10.13...Coil 15.16...Back core 22...Shield ring Fig. 3

Claims (1)

[Claims] 1) A coil bobbin is fitted into a magnetic circuit consisting of first and second cores joined through a magnetic gap and a third core connecting both cores, and on both sides of the magnetic circuit, In a magnetic head formed by bonding a pair of sliders that are in sliding contact with a magnetic recording medium together with the circuit, the entire sides of the first and second cores facing the slider are bonded to one of the sliders; A magnetic head characterized in that the third core is pressed and fixed to the first and second cores by an elastic member provided integrally with the coil bobbin. 2) The magnetic head main body is provided with a shield member that shields the magnetic head body from external noise, and the shield member is engaged with and fixed to the coil bobbin.
The magnetic head described in section.