JPH06150219A - Magnetic head - Google Patents

Abstract

PURPOSE:To provide a highly efficient magnetic head which may be simply processed, with simple jigs, tools, and equipment, and produced at reduced costs by improving a holding member for holding a core or the like. CONSTITUTION:A front core 1 sliding in touch with a magnetic recording medium is formed separately from a back core 2 in the rear of the front core 1. The front core 1 and back core 2 are bonded, thereby, to constitute a magnetic core. The magnetic head has this magnetic core and a holding member 5 for holding the magnetic core. The holding member 5 has positioning parts 5c, 5d for positioning the front core 1.

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 slidingly contacting a magnetic recording medium such as a magnetic card or a magnetic tape with a magnetic core for magnetic recording and reproduction of information, and more particularly to the structure thereof. is there.

[0002]

2. Description of the Related Art As an example of a conventional magnetic head, in a magnetic core, a front part slidingly contacting a magnetic recording medium and a rear part on the opposite side are formed as a front core and a back core, respectively, and these are formed. There are some that use a structure called a bonded crevite type. According to this structure, it is possible to manufacture the front core and the back core with suitable magnetic materials. Usually, the front core uses sendust alloy or ferrite in consideration of wear resistance, and the back core In many cases, a permalloy laminated structure is used in consideration of cost and magnetic characteristics. A holding member is provided to hold these cores in the case.

[0003]

However, in the structure of the magnetic head adopting the above-mentioned crevite type magnetic core, when the back core is manufactured, since the laminated structure is adopted, the required thickness ( In order to achieve the track width), it is necessary to stack many core units. To this end, an adhesive is applied between the single cores and the cores are positioned so that the single cores do not become misaligned to obtain the high temperature and high pressure required to cure the adhesives. Jigs and tools are required.

Further, since the joining portion with the front core portion must be smoothly finished in order to obtain magnetic characteristics, it has a clevite structure intended for low cost, but in the present back core manufacturing. However, the process, jigs, tools, and equipment required for stacking are inevitably costly, and further cost reduction is difficult.

Many of the conventional holding members merely hold the core or the like in the case.

In view of the above problems, the present invention provides a high-performance magnetic head which has an improved holding member for holding a core or the like, which has simple processes, jigs, tools, and cost reductions. The purpose is to

[0007]

In order to solve the problems that have hitherto been held and to achieve the above-mentioned object, the present invention comprises a front core that is in sliding contact with a magnetic recording medium and a back core that is a rear part of the magnetic recording medium as separate bodies. A magnetic head comprising a magnetic core formed by joining the front core and the back core together with a holding member for holding the magnetic core, wherein the holding member has a positioning portion for positioning the front core. It is characterized by that. Further, the holding member is characterized by further having a second positioning portion for positioning the back core.

According to another aspect of the invention, a front core that is in sliding contact with a magnetic recording medium and a back core at the rear are separately formed, and the front core and the back core are joined together. A magnetic head comprising a holding member for holding a core, wherein the holding member has a positioning portion for positioning the back core. The holding member further includes a coil bobbin into which the back core is inserted, and the holding member further includes a second positioning portion that positions the coil bobbin.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a sectional view showing a first embodiment of the present invention. In FIG. 1, 1 is a front core and 2 is a back core. The back core 2 is formed into a U shape by bending a plate-shaped magnetic material. The rounded portion 2a formed by this bending process is formed in a substantially semicircular shape. The tip 2b of the back core 2 is located inside the tip 10a of the front core 1 in the head 10. Therefore, when processing the front end of the front core 1, the back core 2 is not processed, and the joint area between the front core 1 and the back core 2 is kept constant. A coil wire 3 is wound around the bobbin 7. Reference numeral 4 denotes a terminal, which is fixed to the bobbin 7 and connected to the coil wire 3. A core support 5 supports and fixes the back core 2 combined with the bobbin 7. Reference numeral 6 is a shield case, and 8 is a screw, which joins the front core 1 and the back core 2 by applying a pressing force, and grounds the shield case 6.

In this embodiment, the front core 1 is made of sendust alloy, and its characteristics are as follows. Maximum saturation magnetic flux density: 8650 [G], initial magnetic permeability: 40000, coercive force: 0.032 [O _e ], volume resistivity: 105 [μΩ · cm], linear expansion coefficient: 1.3
× 10 ^-5 [/ ° C]. The back core 2 and the shield case 6 are made of permalloy, and their characteristics are as follows.
It is almost as follows. Maximum saturation magnetic flux density: 7500
[G] or more, initial permeability: 30,000 or more, coercive force: 0.
017 [O _e ] or less, volume resistivity: 55 to 65 [μΩ ·
cm], linear expansion coefficient: 1.2 × 10 ⁻⁵ [/ ° C.]. on the other hand,
The core support 5 is made of PPS (polyphenylene sulfide) resin, and its characteristics are as follows: thermal deformation temperature: 260 [° C.] or higher, linear expansion coefficient: 2.2 × 10.
^{It is −5} [/ ° C.] and volume resistivity: 10 ¹⁶ [Ω · cm].

Next, a method of manufacturing the magnetic head 10 will be described with reference to FIG. In addition, in order to make it easier to understand the correlation of the components in each process, the illustration of each process is shown along with the predetermined direction, but in reality it should be oriented in the proper direction in consideration of accuracy and workability. Work is being carried out.

<Step 1> As shown in FIG. 2 (a), the plate-shaped back core 2 is formed into a U-shape by bending.

<Step 2> Next, as shown in FIG. 2 (b), the back core 2 and the bobbin 7 are made to pass through the opening 7a of the bobbin 7 around which the coil wire 3 is wound.
Combine with.

<Step 3> As shown in FIG. 2 (c), the contact portion 7b of the bobbin 7 is attached to the first contact portion 5a of the core support 5.
The bobbin 7 in which the back core 2 is incorporated is temporarily fixed to the core support 5 by abutting with each other.

<Step 4> As shown in FIG. 2D, the core support 5 to which the back core 2 and the bobbin 7 are temporarily fixed is housed in the shield case 6 and fixed in the shield case 6 with the screw 8. In this fixing, the end portion 6a of the shield case 6 is brought into contact with the second contact portion 5b of the core support 5,
This is performed by pressing the back core 2 with the screw 8 screwed into the shield case 6.

<Step 5> As shown in FIG. 3 (e), the front core 1 to which the two cores are joined is brought into contact with the core support 5 for positioning, and the screw 8 is further moved from the state of step 4. The front core 1 and the back core 1 are joined by screwing. In this state, a resin is embedded in the shield case 6 and the resin is further cured to fix the member housed in the shield case 6. In this embodiment, a thermosetting epoxy resin is used for this resin.

<Step 6> As shown in FIG. 3 (f), the portion of the screw 8 protruding from the shield case 6 is removed.

<Step 7> As shown in FIG. 3G, the tip of the front core 1 is ground or polished so that a predetermined gap depth can be obtained.

The magnetic head according to the present invention can be obtained through the above steps.

Next, the core support will be described with reference to FIGS. 4 to 13.

FIG. 4 is a perspective view showing an embodiment of the core support. The first contact portion 5a of the core support 5, the second
As described above, the abutting portion 5b of the bobbin 7 and the end portion 6a of the shield case 6 are abuttingly positioned, respectively. A third contact portion 5c supports the end portion of the back core 2 and also contacts the front core 1 to position the track. 5d is a fourth contact portion,
The bottom portion of the front core 1 is abutted, and the gap depth is set accurately. Reference numeral 5e is a guide portion which serves as a positioning guide for the back core 2. 5f is a 5th contact part with which one end of the bobbin 7 is contacted. 5g is an insertion port into which one end of the back core 2 is inserted. Then, both ends of the back core 2 are supported so as to sandwich the support portion 5h. In this core support 5, since the first contact portion 5a, the second contact portion 5b, and the fourth contact portion 5d are set with reference to the reference surface 5A, the core support 5 is contacted with each contact portion. The members are kept in a highly precise positional relationship with each other. Moreover, since the front core 2 that is in contact with the fourth contact portion 5d is processed with the reference surface 5A as a reference, the processed gap depth can be obtained with high accuracy.

Next, another embodiment of the core support will be described with reference to the drawings. 5 to 8 show that the back core 2 is provided by providing a convex portion at a predetermined position of the core support.
Alternatively, an embodiment is shown in which a pressing force is applied to the front core 1 so that the front core 1 can be held by the core support. In the core support 21 of the embodiment shown in FIG. 5, two convex portions 21b are formed in the lower portion in the drawing of the back core insertion opening 21a, so that the back core 2 can be held. Although the convex portion 21b is formed below the insertion opening 21a in this embodiment, the insertion opening 2
It may be formed in the upper part of 1a. In the core support 22 of the embodiment shown in FIG. 6, a projecting support portion 22a is provided on the core support 5 shown in FIG. 4, and two projecting portions 22b are formed on the side surface of the projecting support portion 22a. Also in this embodiment, the back core 2 can be held. The core support 23 of the embodiment shown in FIG. 7 is provided with a projecting support portion 23a so as to project from the contact surface of the front core 1, and two projecting portions 22b are formed on the inner side surface of the projecting support portion 23a. The front core 1 can be held. In this embodiment, since the front core 1 is pressed against the positioning portion 23c, the front core 1 can be positioned with high accuracy (track positioning). In the core support 24 of the embodiment shown in FIG. 8A, a projecting support portion 24a is provided on the core support 24 in the figure, and projecting portions 24b and 24c are formed on both upper and lower sides of the projecting support portion 24a. . Further, in this embodiment, two back core insertion openings 24d and 24e are formed. And FIG.
As shown in (b), when the core support 24 in which the back core 2 is incorporated is inserted into the shield case 6, the convex portion 24b is pressed by the case 6, and the convex portion 24c applies the pressing force. As a result, the back core 2 is held, and the front core 1 and the back core 2 can be reliably joined to each other. Therefore, the screw 8 in the embodiment shown in FIG. 1 can be omitted. In this embodiment, the convex portion 24b is formed in a semi-cylindrical shape, but it may be formed in a hemispherical shape and provided at the tip of the protruding support portion 24a.

The core support shown in FIGS. 9 to 12 is
Compared to the core support shown in FIG. 4, the number of positioning parts is further increased. The core support 25 shown in FIG. 9 has positioning portions 25a and 25b so as to sandwich the front core 1.
Is provided. With such a configuration, the front core 1 is positioned. In the core support 26 shown in FIG. 10, the insertion opening 26a of the back core 2 has a trapezoidal shape. With such a shape, the hypotenuse portion of the insertion opening 26a engages with the back core 2, so that the back core 2 is held and fixed to the core support 26. 11,
The core supports 27 and 28 shown in FIG. 12 both have a positioning portion that positions and holds the bobbin 7. The core support 27 shown in FIG. 11 positions and holds the bobbin 7 such that the positioning portions 27a and 27b sandwich one end of the bobbin 7. Core support 28 shown in FIG.
Has positioning portions 28a and 28b formed of grooves, and one side of both ends of the bobbin 7 is fitted into the positioning portions 28a and 28b to be positioned and held.

In the core support 28 shown in FIG. 13, one side surface of the insertion port 29a of the back core 2 is opened.
Therefore, the back core 2 can be inserted from the direction of the arrow A, and the assembling becomes easy. Further, since the back core 2 is inserted from the direction of arrow A, the guide protrusion 29b is provided only on one side. The guide protrusion 29b serves as an abutting portion in the side surface direction of the back core 2.

FIG. 14 shows a second magnetic head according to the present invention.
It is sectional drawing which shows the Example of. In this embodiment, instead of the screw 8 used in the first embodiment, an elastic member 9 made of a conductive leaf spring is used. The elastic member 9 presses the back core 2 with its own elastic force, thereby joining with the front core 1. Further, the back core 2 and the shield case 6 are grounded.

The front core 1, the back core 2, and the shield case 6 may be made of other magnetic metal such as ferrite as long as the above-described functions are fulfilled. Further, the core support 5 may also be another member such as an aluminum die cast member or a brass press member as long as it is a non-magnetic material and can hold the core.
By using a conductive member for the core support 5, a grounding member (for example, the screw 8) becomes unnecessary. In this case, in order to positively bring the core support 5 and the back core 2 into conduction, the back core 2 may be fixed to the core support 5 using a conductive adhesive.

[0028]

As is apparent from the above description, in the magnetic head according to the present invention, the holding member for holding the magnetic core formed by joining the front core and the back core has the positioning portion for positioning the front core. Since it has, the head gap depth can be accurately controlled without using a special member.

If the holding member further has a positioning portion for positioning the back core, the performance of the head can be further improved.

Further, since the holding member for holding the magnetic core formed by joining the front core and the back core with each other has the positioning portion for positioning the back core, the positioning of the back core can be performed accurately without using a special member. You can manage it well.

Furthermore, by providing the holding member with a positioning portion for positioning the coil bobbin into which the back core is inserted, the back core can be positioned using the coil bobbin.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a process drawing of the magnetic head shown in FIG. 1, showing steps (a) to (d) of the whole steps shown in FIG.

FIG. 3 is a process drawing of the magnetic head shown in FIG. 1, showing steps (e) to (g) of the overall steps shown together with FIG.

FIG. 4 is a perspective view showing an embodiment of a core support.

FIG. 5 is a perspective view showing another embodiment of the core support.

FIG. 6 is a perspective view showing another embodiment of the core support.

FIG. 7 is a perspective view showing still another embodiment of the core support.

FIG. 8 is a perspective view showing still another embodiment of the core support.

FIG. 9 is a perspective view showing still another embodiment of the core support.

FIG. 10 is a perspective view showing still another embodiment of the core support.

FIG. 11 is a perspective view showing still another embodiment of the core support.

FIG. 12 is a perspective view showing still another embodiment of the core support.

FIG. 13 is a perspective view showing still another embodiment of the core support.

FIG. 14 is a sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 1 front core 2 back core 3 coil wire 5 core support 6 shield case 7 bobbin 8 screw 9 elastic member 10 magnetic head

Claims (4)

[Claims] 1. A magnetic core formed by separately forming a front core slidingly contacting a magnetic recording medium and a back core at a rear portion of the magnetic recording medium, and holding the magnetic core. A magnetic head including a member, wherein the holding member has a positioning portion that positions the front core. 2. The magnetic head according to claim 1, wherein the holding member further positions the back core.
A magnetic head having a positioning portion of. 3. A magnetic core formed by separately forming a front core slidingly in contact with a magnetic recording medium and a back core at the rear portion thereof, and joining the front core and the back core together, and holding the magnetic core. A magnetic head including a member, wherein the holding member has a positioning portion that positions the back core. 4. The magnetic head according to claim 1, further comprising a coil bobbin into which the back core is inserted, and the holding member further includes a second positioning portion that positions the coil bobbin. Magnetic head.