JPH0473206B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a magnetic head, and more particularly to a magnetic head in which a magnetic core equipped with a winding bobbin is fitted and fixed within a case.

[Prior art]

A conventional magnetic head of this type has a structure as shown in FIG.

In the figure, a case designated by reference numeral 1 is a case that houses and supports the components of the magnetic head, and a sliding surface 1a that slides on a magnetic recording medium (not shown) is formed on the front surface of the case. An opening 1b is formed in 1a. Further, an opening 1c is formed on the upper surface of the case 1 for inserting the components of the magnetic head into the case 1.

The reference numeral 2 is a front core, which is formed by butting the halves of a pair of front cores together via a magnetic gap G. A back core 3 having a U-shaped cross section is butted against this front core 2 to form a magnetic core. The core is configured. This back core 3 is formed by joining together a pair of back core halves each having an L-shaped cross section. Further, the front core 2 and the back core 3 are made of a high permeability magnetic material such as ferrite.

Further, the reference numeral 4 denotes a winding bobbin, which is formed in the shape of a spool with flanges 4a and 4b at both ends, and a winding 5 is wound around the shaft between the flanges 4a and 4a. Further, the winding bobbin 4 is formed with a hole 4b having a rectangular cross section and passing through the collars 4a, 4a and the shaft portion therebetween.

When assembling the above components, first fit the bent portions of the half of the back core 3 from both sides into the holes 4b of the winding bobbin 4 and abut the ends of the halves in the holes 4b. 2
Butt together to obtain a magnetic core assembly.

Next, insert the magnetic core assembly into the case 1 through the opening 1c.
case 1 as shown in Figure 2.
Fit inside.

In this case, as shown in FIG. 2, the lower end of the front core 2 and the lower end of the collar 4a of the bobbin 4 are fitted into the grooves 1d and 1e formed on the bottom surface of the case 1, and the front core 2 is positioned. The magnetic gap G side faces the opening 1b of the sliding surface of the case 2. Further, a gap is formed between the collar 4a of the winding bobbin 4 and the rear inner surface of the case 1.

The magnetic core is fixed by fitting the leaf spring 6 into this gap as shown in the figure. In other words, when the flat spring 6, which has a substantially doglegged cross section, is pushed out and fitted into the gap, the flat spring 6 tries to contract to its original shape, but the collar 4a of the winding bobbin 4 is directed toward the opening 1b. This pressing force fixes the magnetic core assembly.

However, according to the above structure, the fitting of the leaf spring 6 is due to the narrow gap between the collar 4a and the case 1, the bending of the leaf spring 6, and the fact that the leaf spring 6 is in line or surface contact with the collar 4a and the case 1. However, this is difficult due to large friction, and the leaf spring 6 cannot be inserted unless pushed in with a relatively large force.

Therefore, when mating, a large force or impact is applied to the magnetic core, especially the back core 3, and if the magnetic core is made of brittle ferrite, chipping may occur.
Otherwise, the applied stress may distort the magnetic properties of the magnetic core.

Furthermore, a plate spring 6 with the above-mentioned fixing structure is required,
This has the disadvantage of increasing the number of parts and increasing costs.

〔the purpose〕

The present invention has been made to solve the above-mentioned conventional drawbacks, and has a simple and inexpensive fixing structure that allows the magnetic core to be fixed in the case without damaging its structure or properties. The purpose is to provide highly reliable magnetic heads.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings. In each figure, the same or corresponding parts as in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed explanations of the same parts will be omitted.

[First Embodiment] FIG. 3 is a longitudinal sectional side view showing the structure of a magnetic head according to a first embodiment of the present invention.

As shown in the figure, in this embodiment, the case 1, front core 2, and back core 3 have the same structure as the conventional one, but the structure of the winding bobbin 4 is different.

That is, the collar 4a of the winding bobbin 4 is formed from a material having a certain degree of elasticity, and the collar 4a has two elongated cavities 4c along the rear inner surface of the case 1, that is, the side edge facing the Z plane. is formed. When a force is applied from the outside to the cavity side, the outer edge portions of the cavities 4c, 4c
The presence of c and 4c results in elastic deformation parts 4d and 4d that elastically deform in the same direction. Furthermore, hemispherical protrusions 4e, 4e are integrally formed approximately at the center of the outer surfaces of the elastically deformable portions 4d, 4d.

In addition, in the structure of this embodiment, in the magnetic core assembly consisting of the front core 2, back core 3, and winding bobbin 4, the dimension between the front end surface of the front core 2 and the end surface of the protrusion 4e of the winding bobbin 4 is as follows. It is configured to be slightly larger than the dimension between the Y plane, which is the inner surface on the sliding surface side of the case 1, and the aforementioned Z plane.

According to the above structure, when fixing the magnetic core assembly within the case 1, it is sufficient to simply fit the assembly into the case 1 through the opening 1c.

During this insertion, the protrusion 4 of the winding bobbin 4
e and 4e come into contact with the edge of the opening 1b on the top surface of the case 1, but in this case, by applying an appropriate pressing force that does not affect the configuration of the magnetic core assembly, the protrusion 4e can be removed. The degree of elastic deformation of the elastic deformation portion 4d is configured such that the elastic deformation portion 4d bends toward the cavity 4c and the protruding portion 4e retracts. That is, the structure is such that the degree of elastic deformation of the elastic deformation portion 4d can be obtained from the position and dimensions of the cavity 4c and the material of the collar 4a. By retracting the protrusion 4c, the magnetic core assembly can be inserted smoothly.

Therefore, no excessive force is applied to the magnetic core assembly during the above-mentioned insertion, and the magnetic core assembly is not damaged either structurally or dynamically.

After fitting, the elastically deformed portion 4 is bent.
d tries to return to its original shape due to the elastic force of the protrusion 4e.
The magnetic core assembly is pressed toward the Y surface of the case 1 due to this reaction and is fixed. That is, the front core 2 is pressed against the Y surface of the case 1 and fixed, and the back core 3 is pressed against the front core 2 and fixed.

As described above, according to this embodiment, fixing can be performed extremely easily, and the magnetic core is not damaged either structurally or in its characteristics when inserted for fixing. Furthermore, the number of parts for the leaf spring 6 is reduced compared to the conventional structure described above.

[Second Embodiment] FIG. 4 shows the structure of a second embodiment of the present invention. As shown in the figure, in this embodiment, the above-mentioned protrusion 4e is not provided for the elastic deformation part 4d of the winding bobbin 4, but instead, similar hemispherical protrusions 1f, 1f are provided correspondingly. is formed on the Z surface of case 1. Even if such a structure is adopted, the same effect as described above can be obtained.

In the configurations of the first and second embodiments described above, the shape of the cavity 4c may be any other shape as long as it can form an appropriate elastic deformation portion, and may be a groove bored from the outer surface of the collar. It's okay.

Further, the shape of the protrusions 4e to 1f is not limited to the above-mentioned hemispherical shape, but of course may have other shapes.

〔effect〕

As is clear from the above description, according to the present invention, in a fixed magnetic head in which a front core and a back core are fitted in a case, a hollow portion is formed in the brim of the winding bobbin in which a winding bobbin is attached to the back core. an elastically deformable portion is integrally formed on one side of the outer periphery of the hollow portion, and a protruding portion is interposed between the elastically deformable portion and the inside of the case to press the back core against the front core. Since a fixed structure is adopted, it is possible to press the back core against the front core and stably press and fix both cores with an extremely simple structure. In the step of fixing the magnetic core consisting of both cores, the magnetic core can be fixed without damaging its structure or properties, and the reliability of the magnetic head can be improved. Further, the above-mentioned fixing process is extremely simplified and the number of parts is reduced compared to the conventional method, so that costs can be reduced.

[Brief explanation of the drawing]

FIGS. 1 and 2 are an exploded perspective view and a longitudinal side view showing the structure of a conventional magnetic head, respectively;
FIG. 3 is a longitudinal sectional side view of a magnetic head according to a first embodiment of the present invention, and FIG. 4 is a longitudinal sectional side view of a magnetic head according to a second embodiment. 1... Case, 2... Front core, 3... Back core, 4... Winding bobbin, 4c... Cavity, 4
d...Elastic deformation part, 4e...Protrusion part.

Claims (1)

[Claims] 1. In a magnetic head in which a front core and a back core are fitted and fixed in a case, a winding bobbin is attached to the back core, a hollow part is formed in the brim of the winding bobbin, and an elastic part is attached to one side of the outer periphery of the hollow part. A magnetic head characterized in that an elastically deformable portion is integrally formed, and a protruding portion is interposed between the elastically deformable portion and the inside of the case to press and fix the back core to the front core.