JPH03250408A - Magnetic head - Google Patents

Abstract

PURPOSE:To facilitate the connection of coil terminals and to enhance the adhesive property of the leg parts of front cores and back cores by using coil bobbins which are erected with plural terminals and are formed with wall parts having specific projections. CONSTITUTION:The bobbins 10 to be used in this magnetic head are embedded with the plural terminals 48 in thick parts 49 formed at the edges of collar parts 12 thereof. The front surfaces of the collar parts 12 are formed with the wall parts 50 having the projecting parts 52, the front end sides of which are chipped at the time of mounting the back cores 22 in the direction orthogonal with the direction where the terminal 48 array. The front ends 32a in the leg parts of a recording and reproducing core 26 and the front ends 36a in the leg parts of an erasing core 30 are projected through insertion holes 18 of the respective bobbins 10 and the projections 52 are mounted between the front ends 32a, 36a and the wall parts 50 in the state of maintaining tight contact with the front ends 32a, 36a without being pressed to the wall parts 50 by pushing down these projections while chipping the same.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic head used in magnetic recording devices such as floppy disk drives and hard disk drives for recording, reproducing, or erasing information.

[Prior Art] Various improvements have been made to the structure of magnetic heads for recording and reproducing information on and from information recording media in order to simplify the structure and improve reliability.

FIGS. 8 and 9 show an example in which the structure of the bobbin around which the excitation coil is wound has been improved.

FIG. 8 shows a bobbin of a magnetic head disclosed in Japanese Unexamined Patent Publication No. 61-165811. In magnetic heads,
The leg side of the front core is magnetically closed to generate a leakage magnetic field from the magnetic gap. Therefore, the connection between the leg side of the front core and the back core requires high adhesion to prevent leakage of the magnetic field. Therefore, the bobbin 10 shown in FIG. 8 has a simple structure that improves the adhesion between the legs of the front core and the back core.

In the figure, collar parts 12 are formed at both ends of the coil winding part of the bobbin 10, and a suppressing part 14 is formed on the upper surface of one of the collar parts 12, and the elastic force of this suppressing part 14 is used to The back core is pressed against the front core legs.

Since the bobbin 10 requires elasticity in the pressing portion 14, it is made of a relatively soft resin, such as a polyacecool resin or a polyester resin (polyacetal, polyoxymethylene).

FIG. 9 shows a magnetic head 16 constructed using this bobbin 10.

In this magnetic head, the front core 20 is inserted into the insertion hole 18 provided at the center of the bobbin 10 from one side of the collar 12 and protrudes to the other side of the collar 12. A back core 22 is arranged between them.

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 suppressing part 14.

Thereby, the back core 22 and the leg portions of the front core 20 are always kept in close contact with each other.

Incidentally, FIGS. 10(A) and 10(B) show the general structure of a front core and a back core used in the construction of such a magnetic head.

In FIG. 2A, the front core 20 includes a recording/reproducing core 26 having a recording/reproducing gap 24, and an erasing gap 28 for erasing both ends of a track on a magnetic recording medium recorded by the recording/reproducing core 26. core 3
Consists of 0.

The recording/reproducing core 26 is composed of an outer core piece 32 and an inner core piece 34, with a recording/reproducing gap 24 formed on the -blade side and a leg portion on the other side. Also,
The erasing core 30 similarly consists of an outer core piece 36 and an inner core piece 38, and both inner core pieces 34 and 3
8 are combined via the glass member 40 to form the front core 2.
0 is configured.

The hack core 22 shown in FIG. 2B is formed in the shape of a rectangular parallelepiped, and a glass member 44 is interposed in the center thereof. This glass member 44 separates the recording/reproducing core 26 side and the erasing core 30 side.

Next, FIG. 11 shows an improved bobbin that facilitates the connection of the ends of the wound excitation coil. The excitation coil 46 wound around the bobbin 10 is generally of an extremely fine wire diameter (several tens of micrometers). Therefore, if the ends of the wires are not tied in advance, there is a risk that the wires will become tangled during soldering to a printed circuit board or the like, which will hinder the work. Therefore, this bobbin 10 has a plurality of terminals 48 erected in advance on one flange portion 12. Therefore, the ends of the wound excitation coil 46 can be tied to the plurality of terminals 48 in advance, and the soldering work at the time of the next connection is facilitated.

[Problems to be Solved by the Invention] However, in the magnetic head shown in FIG.
4 is always pressing the leg end 21 of the front core 20 via the back core 22, so due to the lever principle,
A large strain always occurs at the root 20a of the front core 20 and at the boundary 21a between the front core 20 and the flange 12 on the back core 22 side. Therefore, characteristics tend to deteriorate due to the magnetostrictive effect,
Another problem is that it may break due to impact or the like.

Furthermore, although the bobbin shown in FIG. 11 is designed to facilitate the connection of the excitation coil 46, the excitation coil 46 is connected to the terminal 4.
8, the heat may be transmitted to the flange 12 side of the bobbin 10, causing deformation of the bobbin 10.

Therefore, in the bobbin 10 provided with such a terminal 48,
In order to improve heat resistance, it is made of polyethylene terephthalate resin reinforced with glass fibers, polyester-based liquid crystal polymer resin having heat resistance, or the like.

However, although such resins have excellent heat resistance, they are hard, have poor flexibility, and are brittle. Therefore, in the case of a bobbin provided with such a terminal 48, elastic force cannot be obtained, so it is necessary to press the back core 22 provided in the bobbin shown in FIG. 8 above against the legs of the front core 20. It is difficult to provide a structural member (the pressing portion 14), and at the same time, it remains difficult to provide a member for achieving close contact between the back core and the leg portions of the front core.

OBJECT OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and its purpose is to facilitate the connection of the excitation coil wound around the bobbin, and to connect the back core and the front core. It is an object of the present invention to provide a magnetic head which can obtain close contact with a leg part 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 the following features:
A front core that combines core pieces to form a magnetic gap and has an open leg portion at the end opposite to the magnetic gap side, and an insertion hole into which the leg portion of the front core is inserted, and is provided at both ends on the outer periphery. a coil bobbin in which an excitation coil is wound between the flange portions of the coil bobbin, and a back that is installed in close contact with the tip of the leg of the front core that protrudes through the insertion hole of the coil bobbin, and magnetically closes the leg side of the front core. In the magnetic head, the coil bobbin includes a plurality of terminals that are erected on the flange of the front core on the side where the leg protrudes, and from which terminal ends of the coils wound around the coil bobbin are hung, and the leg protrusions. A wall section that is erected on the outer surface of the side brim portion at a distance slightly wider than the width of the back core from the tip of the protruding leg of the front core, and the back core is provided on the wall surface on the side of the tip of the leg. and a wall portion formed with a protrusion whose tip end is shaved off by an amount corresponding to the width of the back core when it is attached between the wall portion and the leg tip portion that is in contact with the end portion of the coil. The present invention is characterized in that it is easy to use and also provides close contact between the front core legs and the back core.

Further, according to the present invention, the protrusion can be formed at a position where the longitudinal direction thereof is perpendicular to the insertion direction of the back core or in any direction along the insertion direction.

According to the present invention, it is preferable to provide an opening in the collar portion of the coil bobbin provided with the protrusion in order to drop in debris generated from the protrusion scraped off when inserting the back core.

[Function] According to the magnetic head having the above configuration, the end of the excitation coil can be tied to the plurality of terminals provided on the collar of the coil bobbin, and in addition, the collar can be attached to the back core when the back core is attached. By erecting the wall portion on which the protrusion is formed, the tip end side of which is cut by the core, the back core is placed in close contact between the leg end portion of the front core and the protrusion of this wall portion. That is, since the tips of the projections are shaved, the distance between the shaved tips of the projections and the tips of the legs of the front core matches the width of the back core. As a result, the wall portion forms close contact with the leg portions of the back core and the front core without applying any pressing force to the back core. Therefore, by bonding the back core and the front core legs in this state using a separate member, adhesive, or the like, it is possible to easily and stably connect the two.

Furthermore, according to the present invention, the installation position of the protrusion can be arbitrarily selected, and by making the elongated direction of the protrusion coincide with the mounting direction of the back core, the resistance during mounting is relatively small and uniformly distributed throughout the mounting process. It becomes possible to do so.

Then, according to the present invention, the shavings generated when the protrusion is shaving are dropped into the opening provided in the collar of the coil bobbin, and as a result, the shavings are caught between the back core and the flange, reducing assembly accuracy or making it unnecessary. This has the advantage that no stress is applied to the coil bobbin.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

FIG. 1 is a perspective view showing the structure of a bobbin of a magnetic head, which is a characteristic component in the first embodiment of the present invention.
Similar to the conventional bobbin shown in the figure, three terminals 48 are provided on a thick wall portion 49 formed at the edge of the collar portion 12.

The terminal 48 is formed by placing the metal terminal 48 in the mold of the bobbin 10 by insert molding, and embedding the terminal 48 simultaneously with the bobbin 10.

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

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

Next, FIG. 2 shows a perspective view of a magnetic head constructed using the bobbin shown in FIG. 1.

As illustrated, the outer core piece 32 of the recording/reproducing core 26
The leg tip 32a and the outer core piece 3 of the erasing core 30
The leg tips 36a of the six legs each pass through the insertion hole of the bobbin 10 and protrude toward one of the collar portions 12. The back core 22 is inserted between the tips 32a and 36a and the wall 50 from above.

That is, two bobbins 10, one for the recording/reproducing core 26 and one for the erasing core 30, are used facing each other.

Regarding the plurality of terminals 48, the ends of the excitation coils 46 are tangled in the same manner as described in FIG. 11 above.

FIG. 3 shows that the back core 22 is connected to the tip 32 of the front core leg.
FIG. 3 is a schematic cross-sectional view showing a state in which the back core 22 is installed between the tip 32 and the back core 22 from above.
The protrusion 52 is lowered between a or 36a and the wall 50.
It is pushed down to the upper surface of the collar part 12 while scraping.

That is, since the terminal 48 is formed, the material of the bobbin 10 is, for example, polyphenylene sulfide (PPS), polyethylene terephthalate (PET), polybutylene terephthalate (PET), etc., in order to improve heat resistance.
BT) mixed with glass fiber is used. Therefore, by pushing up the edge portion of the back core 22, which has low flexibility and is made of ferrite or the like, while in contact with the edge portion of the back core 22, the protrusion portion 52 can receive the back core 22. The amount corresponding to the width of 22 will be removed. Therefore, the attached back core 22 is not pressed against the wall portion 50 and is placed in close contact with the tip end 32a or 36a of the front core.

In reality, the width of the tip of the protrusion 52 to be shaved is approximately 30 μm.
Although the sizes of the back core, bobbin, etc. are set to be about m, there is also the effect that manufacturing errors can be tolerated within the range of the height of the protrusion 52.

Further, in the first embodiment, the protrusion 52 is formed continuously and horizontally on the inner surface of the wall 50, but it is also possible to form the protrusion 52 in a plurality of parts.

According to the first embodiment described above, the excitation coils are wound around the cores 26 and 30 for recording/reproducing and erasing, respectively, using the bobbin 10 formed using a common mold, and the terminals at the ends of the wound coils are wound. The connection to the next stage can be facilitated by the connection to 48. Furthermore, since the back core 22 is installed in close contact with the leg portion of the front core 20 without being pressed, a stable close contact state can be obtained by fixing in this state with an adhesive or an adhesive member. In this way, since the pressed state is not maintained,
The wall portion 50 is less likely to deteriorate and is less likely to break due to impact.

4 to 7 show a second embodiment of the magnetic head according to the present invention, and members that are the same as or correspond to those of the first embodiment described above are indicated by adding 100 to their reference numerals. It is.

The structure of the second embodiment will be explained with reference to FIG. 4.5.6.

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

Similar to the first embodiment, a thick wall portion 149 is integrally formed in one collar portion 112 of the bobbin 110, and three terminals 148 are embedded therein by insert molding.

A characteristic feature of the second embodiment is that the protrusion 52 of the first embodiment is provided in a different direction. That is, on the upper surface of the collar portion 112, a wall portion 150 is integrally formed with the pair of coil bobbins 110 and is erected in a direction perpendicular to the direction in which the terminals 148 are arranged.

A protrusion 152 is formed on each wall 150 on its inner wall surface, that is, on the surface facing the tip of the leg of the front core that penetrates and protrudes from the insertion hole 118.

The protrusion 152 has an inclined portion 152a on its upper surface, and can guide the back core so that it can be easily attached when it is inserted.

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

A further feature of this embodiment is that the flange 112 is provided with an opening 160 at a position adjacent to the protrusion 152, which allows the back core to scrape the tip of the protrusion 152 as described later. while coil bobbin 1
10, the shavings fall into this opening 160 and are reliably prevented from being caught between the back core and the collar portion 112.

Of course, this opening 160 is not limited to the through opening in the embodiment, but may also be a shallow groove opening.

In the embodiment, in order to prevent the wall portion 150 from becoming weak due to the provision of the opening 160, the inner surface 150a of the wall portion 150 is sloped as shown in the figure, and the root portion thereof is thickened to provide sufficient strength. is obtained.

As described above, according to this embodiment, since the elongated direction of the protrusion 152 is determined along the direction in which the back core is attached, the protrusion 152 extends through the back core while the back core is attached. This makes it possible to perform stable and uniform back core positioning work.

FIG. 7 is a schematic cross-sectional view showing a state in which the back core 122 is attached between the tip 132a of the front core leg portion and the wall portion 150 in the second embodiment.

As is clear from the figure, when the back core 22 is lowered from above between the tip 132a and the wall 150, the back core 122 is pushed down to the upper surface of the collar 112 while scraping the protrusion 152.

In this second embodiment as well, the bobbin 110 is made of PPS, PET, PBT, etc. mixed with glass fiber, as in the first embodiment, so as to withstand heat of at least 280'C or higher. Therefore, the wall portion 150 made of these materials has low flexibility, and is scraped off by the 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 and the wall portion 150 It will be positioned in close contact with the tip 132a.

In the second embodiment just described, the opening 160 is the shavings 1 of the protrusion 152 when the hack core] 22 is installed.
52C, and as a result, shavings 152c become trapped between the back core 122 and the flange 112, deteriorating the assembly accuracy, or applying unnecessary stress to various parts, for example, causing the tip 132a to break. It is possible to reliably prevent such situations.

In addition, in this embodiment, a liquid crystal polymer is used as the material used for the coil bobbin, and the surface thereof is particularly hardened, while the inside is made soft, so that the wall portion 150 has better flexibility than the above-mentioned embodiment. In this case, the wall portion 150 and the protrusion portion 15
2 may be slightly deformed with the attachment of the back core 122, but such deformation does not reduce the positioning effect of the attachment of the back core 122 in the present invention.

[Effects of the Invention] As explained above, according to the magnetic head according to the present invention, not only the ends of the excitation coil can be easily connected by the terminals, but also the back core and the front core can be connected easily with the terminal. A stable close bonding state can be obtained. Thereby, the reliability of the magnetic head can be improved and manufacturing can be facilitated.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the structure of a bobbin according to a first embodiment of the present invention, FIG. 2 is a perspective view of a constructed magnetic head according to the first embodiment, and FIG. 3 is a perspective view of the first embodiment. FIG. 4 is a perspective view showing the bobbin structure of the second embodiment of the magnetic head according to the present invention, and FIG. 5 is a partially cutaway front view of the second embodiment. 6 is a plan view of the second embodiment. FIG. 7 is an explanatory diagram showing the mounting state of the back core in the second embodiment. FIG. 8 is a plan view of the second embodiment. FIG. 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 a front core. FIG. 10 (B) is a perspective view of a bobbin. , a perspective view showing an example of a back core, and FIG. 11 is a perspective view of a bobbin used in a second conventional magnetic head. 10...Bobbin 12...Brim part 18...Insertion hole 48...Terminal 50.150...Wall part 52.152...Protrusion part 160...Opening Fig. 48 Fig. Fig. Fig. Figure 4 Figure 7 Figure 9 (A) (B) Figure 1

Claims (3)

[Claims] (1) A front core that combines core pieces to form a magnetic gap and has an open leg section at the end opposite to the magnetic gap side, and has an insertion hole through which the leg section of the front core is inserted, and a A coil bobbin in which an excitation coil is wound between flanges provided at both ends, and a leg end of the front core that protrudes through the insertion hole of the coil bobbin, and the leg side of the front core is magnetically connected. a back core that closes to the coil bobbin; a plurality of terminals that are erected on the flange of the front core on the leg protruding side and from which terminal ends of the coils wound around the coil bobbin are hung; A wall section is provided on the external surface of the flange on the protruding side of the leg and is erected at a distance slightly wider than the width of the back core from the tip of the protruding leg of the front core. a wall portion formed with a protrusion whose tip side is shaved by an amount corresponding to the width of the back core when the coil is attached between the coil end portion and the wall portion while being in contact with the protruding leg tip end portion; A magnetic head characterized in that it facilitates the connection of the front core legs and the back core and provides close contact between the front core legs and the back core. (2) The magnetic head according to claim (1), wherein the projection formed on the wall portion has a longitudinal direction along the mounting direction of the back core. (3) In the magnetic head according to claim (2), the leg protruding side flange of the coil bobbin provided with the protrusion includes:
A magnetic head characterized in that an opening is provided at a position adjacent to the projection for storing scraps of the projection.