JPS60179902A - Magnetic head - Google Patents

Abstract

PURPOSE:To improve the parallel accuracy and ratio between the magnetic tape rubbing surface and a grinding reference surface of a magnetic head and therefore to improve the reliability of said head, by providing a projected part to secure a spot contact between a core holder and a case and changing the case position within a prescribed range of angles when the core holder is set to the case. CONSTITUTION:A hemispherical projected part 4d is provided at the center of a lower end face 4c of a core holder 4 to secure a spot contact with a case 6. When a head element is put into the case 6 after opening downward a plate spring 5 with pressure, a rear end face 4b of the holder 4 has a contact with a fixed face 8. Then the case 6 is pressed down in the direction shown by arrow heads. Thus the case 6 changes its position freely with the part 4d or the spring 5 defined as a fulcrum in order to control the parallel degree between sides A and B. Under such conditions, a magnetic tape rubbing surface 6a of a magnetic head is ground to keep a highly accurate parallel degree between the surface 6a and a grinding reference surface. This improves the nondefective ratio of the head and improves the reliability of the head with reduction of the cost. Furthermore the thickness of the case 6 is reduced to attain a small and lightweight structure of the head.

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.

[Judong Technology]

A conventional magnetic head of this type has a structure as shown in FIG. In the same figure, a magnetic core U indicated by reference numeral 1 is formed by butting half the cores against each other through a magnetic gap G, and a coil bobbin 2 in which a terminal conductor 3.3 is implanted is attached to the leg, and a core holder 4 is attached to the leg. , 4 are fitted and held. The core holders 4, 4 each have a cross section of 1
It is formed in the shape of a figure 7 block, and a plate spring 5 having a cross section of 1<'' is fitted into the grooves 4a, 4a formed on the upper end surface thereof.

The head element, which is a group 9 consisting of the magnetic core 1 and the leaf spring 5 dimensions 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 1i1) is formed in this magnetic tape sliding surface 6a. Further, the back side of the case 6 is open, and the head element is inserted from this back side, as shown in Fig. 2 (a).
) are fitted as shown. 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 downward and spread out, and the head element has an open 1" portion 6 on the tip end surface of the magnetic core 1.
It is inserted up to a point N where it faces the magnetic tape sliding surface 6a through the magnetic tape 6b. After fitting, the head element is pressed downward by the elastic force of the leaf spring 5, and the lower end surface 4C of the core holders 4, 4 is
The lower head attachment is fixed by being pressed against 6C.

After the above fixing, the A1 eaves tape sliding surface 6a of the case 6 including the A side of the figure, that is, the rear end surfaces 4b and 4b of the core holder 4.4 is used as a reference plane, and the B side, that is, the front end surface of the magnetic core 1.
On the other hand, the grinding process is performed parallel to the A plane as shown by the body line in FIG. 2(l).

However, the state shown in FIG. 2(b) 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.

Actually (in many cases, in case 6, Fig. 3(a)
As shown in the figure, the B plane (magnetic tape sliding surface 1ia) and the C plane shown in the figure, that is, the head mounting surface 6C, are not perpendicular to each other, and there is a deviation of an angle θ. This deviation is caused by the punching of the case 6 during press working.

In addition, in the core holder 4, as shown in FIG. 3 (I), the angle θ at which plane A (the rear end surface 4b of the core holder 4) intersects the plane D shown in the figure, that is, the lower end surface 4c of the core holder 4, is determined in the manufacturing process. There will inevitably be variations.

There are deviations in the angle θ, and variations in the angle θ2, and the edges overlap, so the head element is actually mounted in case 6.
In the case of fitting, as shown in FIG. 4(a), there will be a 5V deviation between the entry surface and the B surface. .

This deviation can be as large as about 0.05°.

In this state, when the magnetic tape sliding surface 1a is ground parallel to surface A, the wall thickness of the case 6 becomes thinner at one end of the magnetic tape sliding surface 1a, as shown in FIG. 3(b). Become,
Tears 7 and unevenness occur, in which 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 enables highly accurate parallelism between the magnetic tape sliding surface and the glass cutting reference surface when fitting the head element and case together in the manufacturing process. The objective is to provide a magnetic head rod that can be obtained in a number of ways, improving length ratio and reliability.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 5(a) and (+)). In both figures, Figure 1 (a) t (
b) to Figures 4(a) and 4(b) The same parts or corresponding parts are marked with the same numbers, and explanations of the same parts are omitted.

As shown in FIGS. 5(a) and (+3), in this embodiment, a protrusion having a semicircular cross section is provided approximately in the middle of the lower end surface 4C of the core holder 4 facing the head mounting surface 6C of the case 6. 4
d was formed. 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 structure described above, as shown in FIG. Insert the head element into the case 6 until it reaches the mating position.

After that, in order to obtain parallelism between the A side and the B side, the A side, that is, the rear end surfaces 4b and 4b of the bump holder 4 are applied to the fixed plane 8, and a jig having a suppressing surface parallel to the A side is attached to the case. 6, and apply a pressing force as shown by arrow F.

In this case, the case 6 can be freely displaced with respect to the core holder 4 of the head element at any angle within the range formed by using the protrusion 4d or the leaf spring 5 as a fulcrum. It is inclined with respect to the A plane and the pressing force I- is J:
When a bending moment is applied, the case 6 is displaced at a certain angle with respect to the core holder 4, and the above-mentioned degree of rotation can be easily obtained with high precision as shown in FIG.

In addition, when suppressing the case 6 using the above-mentioned jig, as shown in Fig. 5 (1)
)), the magnetic tape sliding surface 6a and the core holder 4
The dimension between the rear end surfaces 41), that is, the dimension l between the A side and the B side
If the suppression is stopped when becomes the specified size, side A, 1
Parallelism adjustment on three surfaces and fitting dimension adjustment between the head element and the case can be performed at the same time.

After the above adjustment, the core holder 4 of the head element is pressed against the head mounting surface 6c via the protrusion 4d by the pressing force of the plate 6 as described above, 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, the parallelism of surfaces A and 8 is achieved with high accuracy, which is different from the conventional method! No tears or unevenness will occur on the magnetic tape sliding surface 6a.

In the structure of the above embodiment, the shape of the protrusion 6t4 may be any shape as long as it can serve as a fulcrum for displacement of the case 6 with respect to the core holder 4 of the head element. That is, the cross-sectional shape is not limited to the semicircular shape described above, but may be a pond shape such as a triangle. The protrusions may be provided as a plurality of protrusions arranged in one straight line, or may be provided as a single protrusion.

〔effect〕

As is clear from the above description, according to the magnetic field of the present invention, when the case and the head element are fitted, a protrusion or an elastic member (example) provided on the side surface of the core holder on the side to be pressed against By using the plate spring as a fulcrum, the case can be displaced at an angle within the range of the core holder, making it easy to achieve parallelism between the magnetic tape sliding surface of the case and the grinding reference surface with high accuracy. can. This makes it possible to increase the length ratio of the magnetic head, reduce costs, and improve the reliability of the magnetic head. Also, the thickness of the case is as thick as before! Since it can be made thinner, it also has the effect of making the magnetic head smaller and lighter.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing the structure of a conventional magnetic head, FIG. 2(a) is a sectional view taken along the X plane of FIG. 1 in a fitted state,
Fig. 2(b) is a cross-sectional view showing the state of glazing after mating, Fig. 3(a) and (+) are explanatory drawings showing deviations in actual dimensional accuracy of the case and core holder, respectively. Figure 4 (
a) and (+)) are respectively shown in Figure 3 (a) l (b
5(a) and 5(b) are sectional views showing the fitted state and grinding state of the case and core holder, respectively, and FIG. 5(a) shows the fitted state and parallel FIG. 5(b) is a sectional view showing the degree adjustment, and FIG. 5(b) is a sectional view showing the state after adjustment. 1... Magnetic core 2... Coil bobbin 3... Terminal conductor 4... Core holder 4a... Groove 4 (1...
Projection part 5...Plate spring 6...Case 6a/Magnetic tape sliding surface Patent applicant Canon Electronics Co., Ltd. (CO -〇■ 1?+ Hibiki

Claims (1)

[Claims] In a magnetic head in which a core holder holding a magnetic core is fitted into a case and is pressed into contact with the case using an elastic member to be fixed, a protrusion is provided that brings about point contact between the core holder and the case, and the protrusion or the elastic member A magnetic head characterized in that the case is used as a fulcrum and can be displaced at an angle within a predetermined range with respect to the core holder when the case is fitted.