JPH0473207B2 - - 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 core holder holding a magnetic core is fitted into a case and fixed by being pressed into contact with the case using an elastic member.

[Prior art]

A conventional magnetic head of this type has a structure as shown in FIG. In the figure, a magnetic core denoted by numeral 1 is formed by butting the core halves together via a magnetic gap G, and a coil bobbin 2 on which terminal conductors 3, 3 are implanted is attached to the leg, and a core holder is attached to the core. 4, 4 and is held. The core holders 4, 4 are each formed into a block shape with an L-shaped cross section, and a leaf spring 5, which has a dogleg-shaped cross section, is fitted into the grooves 4a, 4a formed on the upper end surface thereof. .

The head element, which is an assembly consisting of the magnetic core 1 to the leaf spring 5 described above, is fitted into the case 6.

The case 6 has a magnetic tape sliding surface 6a curved toward the front side, and an opening 6b is formed in the magnetic tape sliding surface 6a. The back side of the case 6 is open, and the head element is inserted from the back side and is fitted as shown in FIG. 2a. This figure is a sectional view taken along the X plane of FIG. 1 in a fitted state.

The above-mentioned insertion is performed with the leaf spring 5 pushed downwardly and expanded, and the head element is inserted to a position where the tip end surface of the magnetic core 1 faces the magnetic tape sliding surface 6a through the opening 6b. After fitting, the head element is pressed downward by the elastic force of the leaf spring 5, and the lower end surfaces 4c of the core holders 4, 4 are pressed against the lower head mounting surface 6c of the case 6, thereby being fixed.

After the above fixing, the second side is placed on the magnetic tape sliding surface 6a of the case 6, which includes the A side of the figure, that is, the rear end surfaces 4b, 4b of the core holders 4, 4 as a reference plane, and the B side, that is, the front end surface of the magnetic core 1. As shown by diagonal lines in Figure b, the grinding process is performed parallel to the A plane.

However, the state shown in FIG. 2b is an ideal case in which there is no deviation in the dimensional accuracy of the case 1 and the core holder 4, and the A surface and the B surface are completely parallel.

In fact, in most cases, in case 6, as shown in FIG. 3a, surface B (magnetic tape sliding surface 6a) and surface C shown in the same figure, that is, head mounting surface 6c, are not perpendicular to each other, but at an angle of _1. There is a discrepancy. This deviation is caused by the taper of the case 6 when it is pressed.

In addition, in the core holder 4, as shown in FIG. 3b, the angle at which surface A (the rear end surface 4b of the core holder 4) intersects with the surface D shown in the same figure, that is, the lower end surface 4c of the core holder 4 _, inevitably varies during the manufacturing process. It comes out.

There is a deviation of the above angle ₁ and a variation of angle ₂ , and these overlap, so when the head element is actually fitted into the case 6, the angle shown in Fig. 4a is
As shown in the figure, a deviation occurs in the parallelism between the A plane and the B plane. This deviation can be as large as 0.5°.

In this state, when the magnetic tape sliding surface 6a is ground parallel to surface A, the wall thickness of the case 6 becomes thinner at one end of the magnetic tape sliding surface 6a, as shown in FIG. In this case, the magnetic head must be discarded as a defective product.

〔the purpose〕

The present invention has been made in view of the above circumstances, and has an inexpensive and simple structure that increases the parallelism between the magnetic tape sliding surface and the glass cutting reference surface when fitting the head element and the case in the manufacturing process. The object of the present invention is to provide a magnetic head that can be obtained with high accuracy and improves ratio and reliability.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 5a and 5b. In both figures, the same parts or corresponding parts as in FIGS. 1a, b to 4 a, b are given the same reference numerals, and explanations of the same parts will be omitted.

As shown in FIGS. 5a and 5b, in this embodiment, a protrusion 4d having a semicircular cross section is formed approximately at the center of the lower end surface 4c of the core holder 4, which faces the head mounting surface 6c of the case 6. Therefore, the core holder 4 and the case 6 can be brought into almost point contact via the protrusion 4d.

When fitting the head element into the case 6 in the above structure, as shown in FIG.
Insert the head element into the case 6 until it reaches the fitting position.

After that, in order to achieve parallelism between the A side and the B side, the A side, that is, the rear end surfaces 4b, 4 of the core holder 4 is
b is applied to the fixed plane 8, and a jig having a pressing surface parallel to the A side is applied to the magnetic tape sliding surface 6a (B side) of the case 6, and a pressing force is applied as shown by arrow F.

In this case, the case 6 is the core holder 4 of the head element.
The fifth
As shown in Figure a, when surface B is inclined with respect to surface A and a moment is applied due to pressing force F, case 6 is displaced at a certain angle with respect to core holder 4, as shown in Figure 5b. The above parallelism can be easily obtained with high precision.

In addition, when pressing the case 6 with the above-mentioned jig, the dimensions between the magnetic tape sliding surface 6a and the rear end surface 4b of the core holder 4, that is, surface A and surface B, as shown in FIG.
If the pressing is stopped when the dimension between the surfaces reaches a predetermined dimension, the parallelism of the A and B surfaces and the fitting dimension between the head element and the case can be adjusted at the same time.

After the above adjustment, the core holder 4 of the head element is moved to the protrusion 4d by the pressing force of the leaf spring 6, as described above.
The head element is pressed against the head mounting surface 6c through the head element, and the head element is fixed while maintaining its position.

In this state, the aforementioned magnetic tape sliding surface 6a is ground. In this case, since the parallelism of the A and B surfaces is highly accurate, unlike the conventional method, there is no tearing or unevenness on the magnetic tape sliding surface 6a. It will never occur.

In the structure of the above embodiment, the shape and structure of the protrusion 4d is such that the case 6 is the core holder 4 of the head element.
Any shape or structure may be used as long as it can serve as a fulcrum for displacement within a certain range. That is, the cross-sectional shape is not limited to the above-mentioned semicircle, but may be other shapes such as a triangle. Further, the protrusions may be provided as a plurality of protrusions arranged in a straight line, or may be provided as a single protrusion.

〔effect〕

As is clear from the above description, according to the present invention, in a magnetic head in which a core holder holding a magnetic core is fitted into a case and the core holder is pressed into contact with the case using an elastic member and fixed, there is a gap between the core holder and the case. A structure is adopted in which the core holder is fixed within the case by providing a protrusion with a cross-sectional shape that makes almost point contact between the core holder and the case on the side pressed by the elastic member. Parallelism between the magnetic tape sliding surface of the case and the grinding reference surface can be easily achieved with high precision by displacing the magnetic tape within the range of the angle. This makes it possible to increase the quality ratio of magnetic heads, reduce costs, and improve the reliability of the magnetic heads. Furthermore, since the wall thickness of the case can be made thinner than before, the magnetic head can also be made smaller and lighter.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view showing the structure of a conventional magnetic head, Fig. 2a is a sectional view taken along the X plane of Fig. 1 in the fitted state, and Fig. 2b shows the polished state after fitting. The cross-sectional view, Figures 3a and 3b are explanatory diagrams showing actual dimensional accuracy errors of the case and core holder, respectively, and Figures 4a and b are the fitted state and grinding of the case and core holder in Figures 3a and b, respectively. Figures 5a and 5b are cross-sectional views showing the state, and Figures 5a and 5b are respectively illustrative of the embodiments of the present invention. Figure 5a is a sectional view showing the fitted state and parallelism adjustment, and Figure 5b is the state after adjustment. FIG. 1... Magnetic core, 2... Coil bobbin, 3...
Terminal conductor, 4... Core holder, 4a... Groove, 4d
...Protrusion, 5...Plate spring, 6...Case, 6a
...Magnetic tape sliding surface.

Claims (1)

[Claims] 1. In a magnetic head in which a core holder holding a magnetic core is fitted into a case and the core holder is pressed against and fixed to the case with an elastic member, a protrusion with a cross-sectional shape that brings about point contact between the core holder and the case is attached to the elastic member. A magnetic head characterized in that the core holder is fixed within the case by being provided between the core holder and the case on the side that is pressed against the magnetic head.