JP3389041B2 - Magnetic head - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head for magnetically recording or reproducing information by slidingly contacting a magnetic core around which a winding coil is wound with a magnetic recording medium.

[0002]

2. Description of the Related Art Conventionally, a magnetic head of this type has a pair of core halves 1 for forming a magnetic circuit, as shown in FIG.
a magnetic core 1 composed of a and 1a ', a winding bobbin 9 around which a winding coil 2 for electromagnetic conversion is wound, a non-magnetic spacer 3 for forming a magnetic gap, a noise for reducing external noise. It is composed of a magnetic shield case 5 and a core holder 4 for positioning and holding the magnetic core 1 at a predetermined position in the case 5.

The manufacturing process of the magnetic head is performed as shown in order from FIG. 3A to FIG. 3F. First, as shown in FIG. 3A, the winding bobbin 9 is wound around the coil bobbin 9. , A pair of generally U-shaped core halves 1a, 1a '
Insert the back side of the spacer 3 into the core half 1a, 1
The core halves 1a and 1a 'are temporarily fixed by an external force F such as a spring (not shown) as shown in (b). Then, after checking the track deviation and adjusting it, the adhesive is applied to the core half 1a,
The core halves 1a and 1a 'are fixed by applying it to the joint portion of 1a' and thermosetting.

Thereafter, as shown in (c), the core halves 1a,
The magnetic core 1 made of 1a 'is positioned with respect to the core holder 4, and an adhesive is applied to the joint portion and heat-cured to fix the magnetic core.

Further, as shown in (d), (e) and (f), after the core holder 4 to which the magnetic core 1 is fixed is inserted into the magnetic shield case 5, positioning is performed with a screw 6 or a spring (not shown). Then, after temporarily fixing, the filling resin 10 is poured from the rear portion of the case 5 and thermosetting is performed to fix the magnetic core 1 and the core holder 4. Then, the sliding surface of the magnetic recording medium is finished with a predetermined accuracy to complete the magnetic head.

When magnetic recording is performed on a magnetic recording medium with such a magnetic head, a magnetic flux is generated by passing a signal current through the winding coil 2, and the magnetic flux is generated by the spacer 3 via the magnetic core 1. Leading to the magnetic field, a leak magnetic field is generated on the magnetic gap, and thereby magnetic recording is performed on the magnetic recording medium.

When performing magnetic reproduction, the magnetic flux on the magnetic recording medium is captured by the magnetic gap of the magnetic core 1.
It passes through the winding coil 2 via the magnetic core 1, converts the change in magnetic flux into a reproduction signal current, and converts the reproduction signal current into data through a predetermined amplifier, converter, filter or the like.

[0008]

However, the above-mentioned conventional example has the following drawbacks.

1. Since the number of parts is large, the cost of parts increases.

2. Since the number of times the adhesive is heat-cured is large in the manufacturing process, the number of steps is increased and the cost is increased.

3. Due to the large number of heat-curing times, the number of days (parts) from component insertion to completion is long and work-in-process increases.

4. Since the number of steps is large, the cost increases.

Therefore, an object of the present invention is to provide a magnetic head which has a small number of parts, can be manufactured inexpensively with a small number of steps and a short manufacturing period.

[0014]

In order to solve the above-mentioned problems, according to the present invention, a pair of substantially parallel coils are used in a magnetic head.
A bobbin holder comprising integrally configured and a winding bobbin for winding a core holder and the winding coil for holding the magnetic core consisting of shaped core halves in a predetermined position, the bobbin <br/> down The magnetic core formed on the holder is attached to the bobbin holder.
A pressing portion for fixing against loaders, in the bobbin holder
The pair of core halves formed to penetrate in the track width direction
Has a core insertion hole back part of the body is inserted, the pair
The state where the back part of the core half is inserted into the core insertion hole
And the pair of core halves do not overlap in the sliding direction of the magnetic recording medium.
The front parts of the pair of core halves.
A non-magnetic spacer is sandwiched between the cattle, and the pressing portion
Press the pair of core halves against each other
Adopted the configuration.

As the pressing portion of the bobbin holder, for example, the convex portion formed on the inner side surface of the core insertion hole into which the back portion of the pair of core halves is inserted and the front portion of the pair of core halves are sandwiched. And a plurality of convex portions arranged facing each other.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 shows a structure of a main part of the magnetic head of the present embodiment, and FIG. 2 shows an assembly process in manufacturing the same head.

First, the structure of the magnetic head of this embodiment will be described. The magnetic head comprises the following members.

In FIG. 1, 1a and 1a 'are a pair of core halves constituting a magnetic core forming a magnetic circuit,
Each of them is formed of a high magnetic permeability material into a substantially U-shape.
The substantially U-shaped side faces of the core halves 1a and 1a 'are joined together via a non-magnetic spacer 3 for forming a magnetic gap, and the magnetic core 1 has a substantially square V-shape shown in FIGS. 2 (c) and 2 (d) to be described later.
Is configured. The two lateral sides of the substantially U-shaped core halves 1a and 1a 'overlap each other in the sliding direction of the magnetic recording medium (hereinafter abbreviated as medium) indicated by an arrow X in FIG. A magnetic gap is formed by the spacers 3 between them.

Further, in FIG. 1, 7 is a core holder for positioning and holding the magnetic core at a predetermined position,
A bobbin holder integrally formed with a winding bobbin around which a winding coil is wound. The bobbin holder is integrally formed by resin molding or die molding. The bobbin holder 7 has flange portions 71 and 72 having different thicknesses in the vertical direction in FIG. 1, and the winding coil 2 is wound between the flange portions 71 and 72.

A core insertion hole 73 is formed so as to penetrate the entire bobbin holder 7 at substantially the center of the flanges 71 and 72, and the back portion of the core halves 1a and 1a '(medium sliding surface) is formed in this hole 73. The end portion on the opposite side), that is, the back portion of the magnetic core is inserted. A convex portion 74 is formed on one of the inner side surfaces of the core insertion hole 73 that face each other in the medium sliding direction. This convex portion 74 may be a ridge extending over the entire length of the hole 73,
The length may be shorter than that, or a plurality may be provided.

Here, the thicknesses t1 and t2 of the core halves 1a and 1a 'in the medium sliding direction, and the convex portion 7 in the core insertion hole 73.
The dimensional relationship with the width dimension w1 from the apex of 4 to the inner surface on the opposite side is t1 + t2> w1. Thereby, the core half body 1 inserted in the core insertion hole 73 in the manufacturing process described later.
The back portions of a and 1a 'are pressed by the convex portions 74, the back portions of the core halves 1a' are pressed against the inner surface of the hole 73 opposite to the convex portions 74, and the core halves 1a 'and 1a are pressed against each other. It is made to come into close contact and fixed.

Further, the left side surface and the lower surface in FIG. 1 of the flange portion 72 are the medium sliding directions (arrows) when the bobbin holder 7 is positioned and fixed in a magnetic shield case 5 (see FIG. 2) described later. A reference plane A in the X direction and a reference plane B in the track width direction (arrow Y direction) are set.

A positioning groove 75 for positioning the magnetic core is formed on the outer surface of the flange portion 71.
It is formed so as to communicate with 3. The surface of the groove 75 on the far left side in FIG. 1 is a predetermined distance H from the reference surface A of the flange portion 72 and serves as a reference surface a for positioning the magnetic core in the medium sliding direction. The convex portion 74 of the core insertion hole 73
The inner side surface facing to is the same plane as the reference plane a. The bottom surface (lower surface in the figure) of the positioning groove 75 is a predetermined distance I from the reference surface B of the flange portion 72 and serves as a reference surface b for positioning the magnetic core in the track width direction. As will be described later, one of the core half bodies 1a 'is fitted into the groove 75,
The bobbin holder 7 is pressed against the reference surfaces a and b, and the core half 1a is pressed against the core half 1a '.
The position of the magnetic core in the medium sliding direction and the track width direction with respect to is determined.

A groove 76 for fitting the core half 1a is formed in the lower surface of the flange 72, which serves as the reference surface B, in communication with the core insertion hole 73.

Further, at the end portions of the flange portions 71 and 72 on the medium sliding surface side, two pairs of convex portions 77, 77 'and 78, 7 are arranged so as to face each other in the medium sliding direction.
8'is formed. These protrusions 77, 77 'and 7
Reference numerals 8 and 78 'are for sandwiching and elastically pressing the front portions (end portions on the medium sliding surface side) of the core halves 1a and 1a', that is, the front portions of the magnetic cores. The relationship between the interval w2 between the convex portions 77, 78 and the convex portions 77 ', 78', the thicknesses t1, t2 of the core halves 1a, 1a 'in the medium sliding direction, and the thickness tg of the non-magnetic spacer 3 is: The relationship is t1 + t2 + tg> w2. As a result, as will be described later, the front portions of the core halves 1a, 1a 'fitted between the convex portions 77, 78 and the convex portions 77', 78 'with the non-magnetic spacer 3 interposed therebetween are
They are pressed against each other and held in close contact with each other.

The convex portions 77 ', 7 of the convex portions 77, 78 are
The surface facing 8'is the same surface as the reference surface a or an extended surface thereof. The thickness d1 of the convex portions 77, 78 in the medium sliding direction is larger than the thickness d2 of the convex portions 77 ', 78' in the same direction, whereby the convex portions 77, 78 have a convex portion 77 ', It is more rigid than 78 '. This is because the protrusions 77, 77 'and 78, 78' have core halves 1a, 1 '.
This is to prevent the convex portions 77 and 78 on the reference surface a side from warping when the front portion of a ′ is sandwiched, and to improve the positional accuracy of the magnetic core.

At the rear end of the thicker flange 72 of the bobbin holder 7, terminal conductors 8 and 8'connected to both ends of the winding coil 2 are provided.

Next, in FIGS. 2 (d) and 2 (e), reference numeral 5 denotes a magnetic shield case, which is made of a ferromagnetic material such as permalloy and is a good conductor, and the magnetic core 1 made of core halves 1a and 1a 'is incorporated. The bobbin holder 7 is housed to reduce noise from the outside. An opening 51 for exposing the tip end surface of the housed magnetic core 1 is formed on the front surface of the magnetic shield case 5 that is the medium sliding surface.

Further, 6 is a good conductor for fixing the magnetic core 1 and the bobbin holder 7 at a fixed position in the magnetic shield case 5 and for ensuring electrical continuity between the magnetic core 1 and the magnetic shield case 5. It is a screw made of metal. The screw 6 is tightened in a screw hole formed in the magnetic shield case 5.

Next, the manufacturing process of the magnetic head of this embodiment will be described with reference to FIGS.

In the manufacturing process, first, as shown in FIGS. 2A to 2B, the back portions of the core halves 1a and 1a 'are the core insertion holes 73 of the bobbin holder 7, and the front portions are convex portions 77. Inserted between 77 'and 78, 78' (press fit)
Then, the core halves 1a and 1a 'are fitted into the grooves 76 and 75, respectively.

Next, a core half 1a,
1a 'is opened, the non-magnetic spacer shown in (b) is inserted between the core halves 1a, 1a' as shown in (c), and the jig is removed to close the core halves 1a, 1a '. .

Here, as described above, the core half bodies 1a and 1a 'are pressed by the pressing by the convex portion 74 and the sandwiching and pressing by the convex portions 77, 77' and 78, 78 ', and in close contact with each other. , The core half 1a ′ is pressed against the reference surface a of the positioning groove 75,
The position of the magnetic core 1 made of 1a ′ in the medium sliding direction with respect to the bobbin holder 7 is determined, and the magnetic core 1 is fixed to the bobbin holder 7. The position of the magnetic core 1 with respect to the bobbin holder 7 in the track width direction is determined by pressing the core half 1a 'against the reference surface b when fitting the core half 1a' into the positioning groove 75.

Next, the non-magnetic spacer 3 and the magnetic core 1
After confirming and adjusting the position of, the bobbin holder 7 incorporating the magnetic core 1 is inserted into the magnetic shield case 5 with the screw 6 and the screw 6 is tightened as shown in (d) to (e). The screw 6 contacts the core half 1a ′ of the magnetic core 1,
By tightening the screw 6, the core half 1a 'is further pressed against the reference surface b of the positioning groove 75, and the bobbin holder 7
Is pressed, and the reference surface B is pressed against the inner surface of the magnetic shield case 5. Thus, the position of the magnetic core 1 in the track width direction with respect to the case 5 is determined, and the bobbin holder 7 is fixed in the case 5 together with the magnetic core 1. The front end surface of the magnetic core 1 faces the opening 51 of the case 5. Electrical contact between the magnetic core 1 and the case 5 is obtained by the contact of the screw 6.

By making the left and right width dimensions of the bobbin holder 7 and the left and right width dimensions of the case 5 coincide with each other, the reference surface A of the bobbin holder 7 closely contacts the inner side surface of the case 5 and The position of the magnetic core 1 in the medium sliding direction is determined. Here, the width dimension of the bobbin holder 7 is made slightly smaller than the width dimension inside the case 5, and a convex portion (not shown) is provided on the side surface of the bobbin holder 7 opposite to the reference plane A. The holder 7 may be pressed into the case 5.

Next, a filling adhesive (not shown) is poured from the opening on the back side of the case 5 to cure it. Then, the front surface of the case 5 and the tip end surface of the magnetic core 1 are used as a medium sliding surface to perform processing with a predetermined accuracy to complete the magnetic head.

According to this embodiment, since the bobbin holder 7 having the core holder and the winding bobbin integrally formed is used, the number of parts can be reduced and the cost can be reduced as compared with the conventional case. In addition, in the assembly process, the core halves 1a and 1a 'are fixed to each other and the magnetic core 1 is fixed to the holder 7 by protruding portions 74, 77, 7 of the holder.
Since it is performed by pressing 7 ', 78, 78' and not by adhesion as in the conventional example, the number of assembling steps can be reduced, the manufacturing period can be greatly shortened, and the cost can be reduced.

[0038]

As is apparent from the above description, according to the present invention, in the magnetic head, a pair of substantially U-shaped U-shaped
A bobbin holder comprising integrally configured and a winding bobbin for winding a core holder and the winding coil for holding the magnetic core consisting of A half at a predetermined position, the magnetic core formed on said bobbin holder To the bobbin holder
And the track width on the bobbin holder.
Back of the pair of core halves formed so as to penetrate in the direction
A pair of core halves having a core insertion hole into which a part is inserted,
With the back portion of the core inserted into the core insertion hole,
The pair of core halves are arranged so that they overlap in the sliding direction of the magnetic recording medium.
Placed between the front parts of the pair of core halves.
A non-magnetic spacer is sandwiched, and the pressing portion includes the pair of pressing members.
Since the core halves are pressed so that they can be pressed against each other, the magnetic head having a small number of parts, a small number of steps, and a short manufacturing period can be manufactured at low cost, which is an excellent effect.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a structure of a main part of an embodiment of a magnetic head according to the present invention.

FIG. 2 is an explanatory diagram showing a manufacturing process of the magnetic head.

FIG. 3 is an explanatory view showing a manufacturing process of a conventional magnetic head.

[Explanation of symbols]

1 magnetic core 1a, 1a 'core half 2 winding coil 3 Non-magnetic spacer 5 Magnetic shield case 6 screws 7 bobbin holder 8,8 'terminal conductor 71,72 Flange part 73 Core insertion hole 74 Convex part 75 Positioning groove 76 groove 77, 77 ', 78, 78' Convex part

Claims (5)

(57) [Claims] 1. A configuration in integrating the winding bobbin winding the core holder and the winding coil for holding the magnetic <br/> air core consisting of core half of a pair of generally U-shape in a predetermined position and a bobbin holder comprising, said magnetic core formed on said bobbin holder the ball
The pressing part that is fixed to the bin holder and the bobbin holder that penetrates in the track width direction are formed.
The core insert into which the back parts of the pair of core halves are inserted.
Has an insertion hole and inserts the back part of the pair of core halves into the core insertion hole
The pair of core halves slide in the magnetic recording medium
Are arranged so as to overlap each other, and the flow of the pair of core halves is
A non-magnetic spacer is sandwiched between the
The pressing portion can press the pair of core halves against each other.
The magnetic head is characterized by pressing like 2. The bobbin holder has one outer surface,
A groove for positioning the magnetic core is provided, a part of the magnetic core is fitted in the groove, and the inner surface of the groove serves as a reference surface in each of the sliding direction of the magnetic recording medium and the track width direction. The magnetic head according to claim 1 , wherein the positions of the magnetic core with respect to the bobbin holder in the sliding direction and the track width direction of the magnetic recording medium are determined by being pressed against the two surfaces. 3. A front part as a pressing part of the bobbin holder
A convex portion formed on the inner surface of Kiko A insertion hole, the pair
The magnetic head according to claim 1 or 2 , further comprising a plurality of convex portions arranged to face each other so as to sandwich the front portion of the core half body . 4. A plurality of convex portions of the bobbin holder that sandwich the front portions of the pair of core halves are arranged to face each other in the sliding direction of the magnetic recording medium, and the magnetic core of the convex portions of the plurality of convex portions is disposed. 4. The magnetic head according to claim 3 , wherein one convex portion on the reference surface side for positioning in the sliding direction of the magnetic recording medium is formed so as to have higher rigidity than the other convex portion. The method according to claim 5, wherein said bobbin holder, a magnetic head according to any one of claims 1 to 4, wherein a plurality of terminal conductors that are connected to the winding coils are implanted .