JP2945119B2 - Magnetic head - Google Patents

Description

The present invention is used in a magnetic recording device such as a floppy disk drive or a hard disk drive to record information,
The present invention relates to a magnetic head for performing reproduction or erasing.

2. Description of the Related Art Various improvements have been made to the structure of a magnetic head for recording / reproducing information on / from an information recording medium in order to simplify the structure and enhance reliability and the like.

FIGS. 8 and 9 show an example in which the structure of the bobbin for winding the exciting coil is improved.

FIG. 8 shows a bobbin of a magnetic head disclosed in Japanese Patent Application Laid-Open No. 61-165811. In the magnetic head, the leg side of the front core is magnetically closed to generate a leakage magnetic field from the magnetic gap. Accordingly, the connection between the front core and the back core on the leg side requires high adhesion so that the magnetic field does not leak. Thus, the bobbin 10 shown in FIG. 8 has a simple structure to improve the adhesion between the leg of the front core and the back core.

In the drawing, at both ends of the coil winding portion of the bobbin 10, a flange portion 12 is formed, and a pressing portion 14 is formed on the upper surface of the one flange portion 12, and the elastic force of the pressing portion 14 is used. The back core is pressed against the front core leg.

The bobbin 10 requires elasticity in the pressing portion 14, and is therefore formed of a relatively soft resin, for example, a resin such as polyacetal or polyester (polyacetal, polyoxymethylene).

FIG. 9 shows a magnetic head 16 configured using the bobbin 10.

In this magnetic head, one flange 12 is inserted through an insertion hole 18 provided in the center of the bobbin 10 from the side of the other flange 12.
The back core 22 is arranged between the leg tip 21 of the front core 20 protruding to the side and the pressing portion 14. This back core
22 is pressed against the leg side of the front core 20 by a pressing force based on the elasticity of the pressing portion 14. Thus, the back core 22 and the leg of the front core 20 are always kept in close contact with each other.

FIGS. 10A and 10B show general structures of a front core and a back core used in such a configuration of the magnetic head.

In FIG. 1A, a front core 20 includes a recording / reproducing core 26 having a recording / reproducing gap 24 and a recording / reproducing core 26.
An erasing core 30 having an erasing gap 28 for erasing both side edges of a track on a magnetic recording medium recorded by the above method.

The recording / reproducing core 26 includes an outer core piece 32 and an inner core piece 34. The recording / reproducing gap 24 is formed on one side, and the other side is configured as a leg. Similarly, the erasing core 30 also includes an outer core piece 36 and an inner core piece 38, and both inner core pieces 34 and 38 are
To form a front core 20.

The back core 22 shown in FIG. 7B is formed in a rectangular parallelepiped shape, and a glass member 44 is interposed at the center.
The recording / reproducing core 26 side and the erasing core are
It is separated into 30 sides.

Next, FIG. 11 shows an improved bobbin for facilitating connection of the ends of the exciting coil to be wound. The exciting coil 46 wound around the bobbin 10 generally has an extremely fine wire diameter (several tens of μm). Therefore, if the ends of the wires are not tangled in advance, they may be entangled during soldering to a printed circuit board or the like, which may hinder the work. In view of this, the bobbin 10 has a plurality of terminals 48 set up on one flange portion 12 in advance. Therefore, the ends of the wound excitation coil 46 are connected to the plurality of terminals 48 in advance.
Therefore, simplification of the soldering work at the time of the next connection is achieved.

[Problems to be Solved by the Invention] However, in the magnetic head of FIG.
14 always presses the leg tip 21 of the front core 20 via the back core 22, so that the lever 21 principle allows the base 20 a of the front core 20 and the boundary 21 a between the flange 12 on the back core 22 side. Large distortion always occurs. Therefore, there is a problem that the characteristics are likely to be degraded due to the magnetostrictive effect, and there is a possibility that the characteristics are broken due to an impact or the like.

Further, in the bobbin shown in FIG. 11, the connection of the exciting coil 46 is facilitated, but when the exciting coil 46 is pre-soldered to the terminal 48, the heat is transferred to the flange 12 side of the bobbin 10. This may cause the bobbin 10 to be deformed. Therefore, the bobbin 10 provided with such terminals 48 is made of a polyethylene terephthalate resin reinforced with glass fibers, a polyester-based liquid crystal polymer resin having heat resistance, or the like in order to improve heat resistance.

However, such a resin is excellent in heat resistance,
It is hard, inflexible and brittle. Accordingly, in the case of a bobbin provided with such terminals 48, no elastic force can be obtained, so that the back core 22 provided on the bobbin shown in FIG. It is difficult to provide a suitable component (pressing portion 14), and at the same time, it is difficult to provide a member for obtaining the adhesion between the back core and the leg of the front core.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the invention is to facilitate connection of an exciting coil wound around a bobbin, and to provide a back core and a front core. It is an object of the present invention to provide a magnetic head capable of obtaining adhesion to a leg with a simple structure.

Means for Solving the Problems In order to achieve the above object, a magnetic head according to the present invention has a front surface in which a magnetic gap is formed by combining core pieces, and an end opposite to the magnetic gap side is an open leg. A core, a coil bobbin having an insertion hole through which a leg portion of the front core is inserted, and an excitation coil wound between flange portions provided at both ends on the outer periphery, and projecting through the insertion hole of the coil bobbin. A back core that is closely attached to a leg tip of the front core and magnetically closes a leg side of the front core, wherein the coil bobbin includes:
A plurality of terminals provided on the flange of the leg protrusion of the front core, the terminals being provided with ends of coils wound around the coil bobbin; and the protrusion of the front core on the outer surface of the leg protrusion side flange. A wall portion erected from the front end portion with a slightly wider distance than the width of the back core, and a wall portion on the side of the front end portion of the leg portion is brought into contact with the wall portion while contacting the back core with the front end portion of the protruding leg portion. And a wall with a projection whose tip is cut by the width of the back core when mounted between the front core and the front core leg and the back core as well as easy connection of the coil end. It is characterized by obtaining the nature.

Further, according to the present invention, the formation position of the protrusion can be any direction in which the longitudinal direction is orthogonal to or along the insertion direction of the back core.

According to the present invention, it is preferable that an opening is provided in a flange portion of the coil bobbin provided with the protrusion in order to drop off debris generated from the protrusion shaved off when the back core is inserted.

[Operation] According to the magnetic head having the above configuration, the ends of the exciting coil can be wrapped around a plurality of terminals provided on the collar portion of the coil bobbin. In addition to this, the back portion is attached to the collar portion when the back core is attached. The back core is installed in a state in which the back core is in close contact with the front end of the leg of the front core and the projection of the wall, since the wall having the shape of the protrusion whose front end is shaved by the core is erected. That is, since the tip of the projection is shaved, the distance between the shaved tip of the protrusion and the tip of the leg of the front core is equal to the width of the back core. Thus, the wall portion is in close contact with the legs of the back core and the front core without applying a pressing force to the back core. Therefore, in this state, the back core and the front core leg are bonded to each other by using a separate member, an adhesive, or the like, so that it is possible to easily and stably connect the both legs in a stable state.

Further, according to the present invention, the installation position of the projection is arbitrarily selected, and if the longitudinal direction of the projection is made to coincide with the mounting direction of the back core, the resistance at the time of mounting is relatively small and is uniformly distributed throughout the mounting. It is possible to do.

The shavings generated when shaving the projections are dropped into the opening provided in the flange portion of the coil bobbin according to the present invention, whereby the shavings are caught between the back core and the brim portion, thereby lowering the assembly accuracy or eliminating unnecessary There is an advantage that no excessive stress is applied to the coil bobbin.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing a configuration of a bobbin of a magnetic head which is a characteristic component in the first embodiment of the present invention.
In the figure, one terminal 12 of the bobbin 10 is provided with three terminals 48 on a thick portion 49 formed at the edge of the flange 12 similarly to the conventional bobbin shown in FIG. . This terminal 48
The metal terminal 48 is set in the mold of the bobbin 10 by insert molding, and is buried at the same time as the bobbin 10.

A wall 50 is provided on the upper surface of the flange 12 in a direction perpendicular to the direction in which the terminals 48 are arranged. In the first embodiment, two flanges 12 are arranged opposite to each other at the edge.
This is because, as shown in the magnetic head configuration diagram of FIG. 2, since the bobbins 10 are disposed so as to face left and right, a single mold can be used to form a bobbin that can handle both left and right.

A protrusion 52 is formed on the inner wall surface of the wall portion 50, that is, on a surface facing the tip of the leg portion of the front core that protrudes through the insertion hole 18.

Next, FIG. 2 is a perspective view of a magnetic head constituted by using the bobbin of FIG.

As shown in the drawing, the leg tip 32a of the outer core piece 32 of the recording / reproducing core 26 and the leg tip 36a of the outer core piece 36 of the erasing core 30 respectively penetrate through the insertion hole of the bobbin 10 and are on one side of the flange 12 It protrudes. The back core 22 is mounted between the front ends 32a and 36a and the wall 50 by being pushed from above.

That is, two bobbins 10 for the recording / reproducing core 26 and for the erasing core 30 are used to face each other. As for the plurality of terminals 48, the ends of the exciting coil 46 are cut off in the same manner as described in FIG.

FIG. 3 shows that the back core 22 is the front end 32a of the front core leg.
Or 36a is a schematic cross-sectional view showing a state of being mounted between the wall portion 50, the back core 22 from the upper end 32a or 36a
And between the wall 50 and the projection 52 while shaving the projection
It is pushed down to the top of 12.

That is, the material of the bobbin 10 is, for example, polyphenylene sulphite (PPS), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), or the like, in order to improve the heat resistance because the terminal 48 is formed. Is used. Accordingly, by pressing down the edge portion of the back core 22 made of ferrite or the like having a small flexibility while being in contact with the inclined surface of the projection 52, the portion of the projection 52 is
Is cut off by an amount corresponding to the width of the back core 22. Therefore, the mounted back core 22 is installed without being pressed by the wall 50 and in a state of being in close contact with the front end 32a or 36a of the front core.

Actually, the width of the tip to be cut off of the projection 52 is about 30 μm
Although the sizes of the back core 22, the bobbin 10, and the like are set to be about the same level, there is an effect that a manufacturing error can be allowed within the range of the height of the projection 52.

In the first embodiment, the projection 52 is formed horizontally and continuously on the inner surface of the wall 50, but it may be divided into a plurality of portions.

According to the first embodiment described above, each coil for recording / reproducing and erasing is formed by the bobbin 10 formed by a common mold.
The winding of the exciting coil for 26 and 30 and the connection of the wound coil terminal to the terminal 48 can facilitate the connection work to a circuit board or the like. Further, since the back core 22 is closely attached to the leg of the front core 20 without being pressed, a stable close contact state can be obtained by fixing the back core 22 with an adhesive or an adhesive member in this state. . Thus, since the pressed state is not maintained, the deterioration of the wall portion 50 is small, and
Less likely to break due to impact.

4 to 7 show a second embodiment of the magnetic head according to the present invention. Members which are the same as or correspond to those of the first embodiment described above are shown by adding 100 to their reference numerals. is there.

 The structure of the second embodiment will be described with reference to FIGS.

Although not shown in detail, a coil for recording / reproducing or erasing is wound around the bobbin 110 by a well-known winding machine.

As in the first embodiment, a thick portion 149 is integrally formed on one of the flange portions 112 of the bobbin 110, and three terminals 148 are embedded and formed by insert molding.

A characteristic of the second embodiment is that the projections 52 of the first embodiment are provided in different directions. That is, on the upper surface of the collar portion 112, a pair of wall portions 150 are erected on the coil bobbin 110 in a direction perpendicular to the direction in which the terminals 148 are arranged.

In each of the wall portions 150, a protrusion 152 is formed along an inner wall surface, that is, a surface of the front core, which faces through the insertion hole 118, and faces a tip end portion of the leg portion of the front core. It is formed continuously.

The projecting portion 152 has an inclined portion 152a on its upper surface, and can guide the back core so as to be easily mounted when the back core is received.

Further, as shown by reference numeral 152b, the tip of the projection 152
Its cross section has a half-moon shape, and has a shape that can be easily scraped off by the back core.

A further characteristic feature of the present embodiment is that an opening 160 is provided at a position adjacent to the protrusion 152 of the collar 112 so as to surround the protrusion 152, thereby enabling the back core to be described later. When mounted on the coil bobbin 110 while shaving the tip of the projection 152, the shavings fall into the openings 160, thereby reliably preventing the shavings from being caught between the back core and the collar portion 112. .

Of course, this opening 160 can be a shallow groove opening as well as the through opening in the embodiment.

In the embodiment, the inner surface 15 of the wall portion 150 is provided to prevent the wall portion 150 from being weakened by providing the opening 160.
0a is provided with a slope as shown in the figure, and a sufficient strength is obtained by making the root portion thicker.

As described above, according to the present embodiment, since the longitudinal direction of the projection 152 is determined along the mounting direction of the back core, the projection 152 is consistently scraped by the back core during the mounting of the back core. As a result, a stable and uniform back core positioning operation can be performed.

FIG. 7 is a schematic sectional view showing a state in which the back core 122 is being mounted between the front end 132a of the front core leg and the wall 150 in the second embodiment.

As is clear from the figure, when the back core 122 is lowered from above to between the tip 132a and the wall 150, the back core 122
Is pressed down to the upper surface of the collar 112 while shaving the projection 152.

In the second embodiment, as in the first embodiment, the bobbin 110 is made of PPS, PET, PBT or the like mixed with glass fibers so as to withstand heat of at least 280 ° C. or more. Therefore, the wall portion 150 made of these materials has low flexibility, and is cut off by an edge portion of the back core 122 by an amount corresponding to the width of the back core 122,
As a result, the back core 122 is positioned in close contact between the wall 150 and the tip 132a.

In the second embodiment just described, the opening 160 receives the shavings 152c of the projection 152 when the back core 122 is mounted, and as a result, the shavings 152c are interposed between the back core 122 and the collar 112. Thus, it is possible to reliably prevent a situation in which the assembling accuracy is degraded or unnecessary stress is applied to each part to break the tip 132a, for example.

Further, in the present embodiment, a liquid crystal polymer is used as a material used as the above-described coil bobbin, and the surface thereof is hardened, while the inside is softened, so that the wall portion 150 which is more flexible than the above-described embodiment is used. In this case, the wall 150 and the projection 152 may be slightly deformed with the mounting of the back core 122, but such deformation may cause the back core 122 of the present invention to be deformed. The positioning effect of mounting is not reduced.

[Effects of the Invention] As described above, according to the magnetic head of the present invention, not only the terminals facilitate the connection of the ends of the exciting coil, but also the back core and the front core have a simple structure. And a stable state of close contact bonding can be obtained. Thereby, it is possible to improve the reliability of the magnetic head and to facilitate the manufacture.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the structure of a bobbin of a first embodiment of the present invention, FIG. 2 is a perspective view of a magnetic head according to the first embodiment, and FIG. 3 is a first embodiment. FIG. 4 is a perspective view showing a bobbin structure in a second embodiment of the magnetic head according to the present invention, and FIG. 5 is a partially broken front view of the second embodiment. FIG. 6, FIG. 6 is a plan view of the second embodiment, FIG. 7 is an explanatory view showing a mounted state of the back core in the second embodiment, and FIG. 8 is used for a first conventional magnetic head. 9 is a perspective view of a magnetic head using the bobbin shown in FIG. 8, FIG. 10 (A) is a perspective view showing an example of the front core, and FIG. 10 (B) is FIG. 11 is a perspective view showing an example of a back core. FIG. 11 is a perspective view of a bobbin used in a second conventional magnetic head. 10 bobbin 12 brim 18 insertion hole 48 terminal 50, 150 wall 52, 152 protrusion 160 opening

Claims (3)

(57) [Claims] 1. A front core having a magnetic gap formed by combining core pieces and having an open leg at an end opposite to the magnetic gap, and an insertion hole through which the leg of the front core is inserted. A coil bobbin in which an exciting coil is wound between flanges provided at both ends of an outer periphery of the front core, the coil bobbin being disposed in close contact with a tip end of a leg portion of the front core that protrudes through the insertion hole of the coil bobbin; A back core that magnetically closes the open leg side, wherein the coil bobbin has a plurality of terminals erected on a flange portion of the front core on the leg protruding side, and a terminal to which the end of the coil is entangled; A wall portion erected on the outer surface of the leg protruding side flange portion at a distance slightly larger than the width of the back core from the protruding tip end portion of the front core, wherein the wall portion has a leg tip end side; of A wall having a projection formed on the surface, the tip of which is shaved by an amount corresponding to the width of the back core when the back core is attached to the wall while contacting the tip of the protruding leg. A magnetic head, characterized in that it has an easy connection of coil ends and a close contact between the front core open leg and the back core. 2. The magnetic head according to claim 1, wherein the projection formed on the wall has a longitudinal direction provided along a mounting direction of the back core. 3. The magnetic head according to claim 2, wherein an opening for accommodating shavings of the projection is provided at a position adjacent to the projection on a leg-projecting side flange of the coil bobbin provided with the projection. A magnetic head, wherein the magnetic head is provided.