JPS6355125B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic head, and particularly to a method for simply and reliably fixing the magnetic core in a predetermined position.

1 to 5 show a conventional method of fixing the magnetic core of a magnetic head, and FIGS. 1 to 3 show the first conventional example, and FIGS.
The figure shows a second conventional example.

In Fig. 1, 1 is a magnetic core, 2 is a coil wound around the magnetic core 1, 3 is a hold case that supports the magnetic core 1, 4 is a terminal plate fixed to the rear of the hold case 3, and 5 is an external These are terminal pins that connect to the circuit. The magnetic core 1 is divided into two parts for convenience in manufacturing and assembly, and one of the divided parts is shown in the figure.

A magnetic core fitting groove 7 is formed in the front wall of the hold case 3, into which the magnetic core 1 is fitted, and for causing the tip of the magnetic core 1 to protrude from the hold case 3. The magnetic core fitting groove 7 consists of an inner wall 8 on the side of the center line of the magnetic head indicated by the line O-O, a bottom wall 9, and an outer wall 10 on the outside with respect to the line O-O.
When the magnetic core 1 is fitted, the magnetic core 1 is supported by the bottom wall 9, and the side surface of the magnetic core 1 on the line O-O side is in contact with the inner wall 8. The groove width of the magnetic core fitting groove 7 is formed to be slightly larger than the width of the magnetic core 1 so that the magnetic core 1 can be easily fitted. There is a very small gap between the sides.

A recess 12 is further provided in the front wall of the hold case 3 adjacent to the magnetic core fitting groove 7 . This recess 12 includes an inner wall 13 on the line O-O side, a bottom wall 1
4. It is formed by an outer wall 15 and a front wall 16. The distance between the outer wall 10 of the magnetic core fitting groove 7 and the inner wall 13 of the recess 12 is narrow, and a fixing rib 17 is formed by both side walls 10 and 13. Note that a step portion 20 is provided on the rear wall of the hold case 3, and supports the magnetic core 1 together with the bottom wall 9.

In such a configuration, a caulking punch 18 is used to fix the magnetic core 1 to the hold case 3. The tip of the caulking punch 18 is formed to be slightly smaller than the width of the recess 12, and a taper 19 is attached to the tip. After fitting the magnetic core 1 into the magnetic core fitting groove 7, use the caulking punch 1.
Insert the tip of 8 into the recess 12 and press the caulking punch 18.
When the rib 17 is forcibly hammered into the recess 12, the rib 17
expands toward the magnetic core fitting groove 7 and is finally pressed strongly against the side surface of the magnetic core 1. This results in
The magnetic core 1 will be fixed to the hold case 3.

However, if the crimping is too strong, the magnetic core 1 will be deformed and the magnetic properties will deteriorate, and if the crimping is too weak, the magnetic core 1 may move without being completely fixed. There was a drawback that it had a negative effect on the characteristics.

Next, a second conventional example will be explained. While the first conventional example fixes by caulking as described above, the second conventional example fixes the magnetic core 1 to the hold case 3 with adhesive. The bonding method is shown in FIG. 4 and FIG. 5, which is a sectional view taken along the line--line in FIG. Note that the same parts as in the first conventional example are given the same reference numerals. The second conventional example differs from the first conventional example in that the recess 12 in the first conventional example is not formed. In the second conventional example, the magnetic core 1 is fitted into the magnetic core fitting groove 7, and then the side surface of the magnetic core 1 in the magnetic core fitting groove 7, the inner wall 8 of the magnetic core fitting groove 7, and the outside Hold the magnetic core 1 by injecting adhesive into the gap between the wall 10 and the case 3
It is to be fixed at

By the way, in the caulking fixation in the first conventional example, since the magnetic core 1 is secured by caulking the rib 17, the dimensions of the magnetic core fitting groove 7 do not require such precision. However, in the second conventional example, although there is no fear that the magnetic core 1 will be deformed, the magnetic core fitting groove is arranged so that the gap is as small as possible when the magnetic core 1 is fitted into the magnetic core fitting groove 7. must be formed,
The drawback is that extremely high dimensional accuracy is required. In addition, since some gaps inevitably exist, when bonding with adhesive, the magnetic core 1
cannot be regulated to a fixed position, resulting in variations in position, and furthermore, the bonding process is difficult to automate.

The present invention provides a magnetic core fixing method that does not have the drawbacks of the first and second conventional examples.

6, 7, 8, and 9 are diagrams showing the magnetic core fixing method of the present invention, in which FIG. 6 is a plan view, FIG. 7 is a sectional view taken along the line - in FIG. 6, and FIG. FIG. 8 is a sectional view taken along the line - in FIG. 6. Reference numeral 1 denotes a magnetic core, and a bobbin (not shown) around which a coil is wound is inserted into the rear upright portion of the magnetic core. Reference numeral 3 denotes a hold case, and a magnetic core fitting groove 7 is formed in the front wall of the hold case as in the conventional example. The magnetic core 1 is fitted into the magnetic core fitting groove 7, and the magnetic core 1 is fitted into the magnetic core fitting groove 7.
The distal end portion protrudes from the hold case 3.

While the conventional method for fixing the magnetic core 1 uses a hold case 3, the present invention fixes the magnetic core 1 using an insert. Figure 9 shows insert 2 used in this invention.
1 is shown in plan view. The insert 21 is
The central portion 22 and the central portion 22 are made of a material that deforms due to heat such as zinc or polyacetal resin.
It is composed of a side part 23 that is integrated with the main body and extends parallel to the side thereof. Both sides 24 of the central part 22
As will be described later, when the magnetic core 1 is fitted between the center portion 22 and the side portions 23, it becomes a reference plane A for positioning the magnetic core 1. The side surface 2 is located near the tip of the side portion 23 of the insert 21.
An enlarged portion 25 is formed that protrudes toward the magnetic core 1 , and the inner surface of the enlarged portion 25 serves as a contact surface 26 that comes into contact with the magnetic core 1 . The enlarged portion 25 is provided with a hole 27 into which a heating punch 29 is inserted as described later.

Next, the magnetic core fixing method of the present invention will be explained.

First, the insert 21 is inserted into a predetermined position within the hold case 3 as shown in FIG. Then,
A magnetic core 1 is placed between the central part 22 and the side parts 23 of the insert 21. At this time, the tip of the magnetic core 1 fits into the magnetic core fitting groove 7. Although FIG. 6 shows the magnetic core 1 placed so that the side surface of the magnetic core 1 and the side surface 24 of the central portion 22 are in contact with each other, there may be a gap between the two. do not have. The magnetic core 1 is placed so that its rear end surface abuts the fitting rear surface 28 of the insert 21.

In this state, as shown in FIG. 7, when a heating punch 29 heated to, for example, 450° C. is inserted into the hole 27 of the enlarged portion 25, the enlarged portion 25 softens and the contact surface 26 of the enlarged portion 25 becomes flat. The side surface of the magnetic core 1 will be pressed, and as a result, the magnetic core 1 will be pressed against the side surface 24 of the central part 22 of the insert 21. Therefore, after cooling, the magnetic core 1 is pressed and fixed along the side surface 24 which becomes the reference surface A. As long as the side surface 24 is formed accurately, the magnetic core 1 will also be accurately fixed in a predetermined position.

In this way, in this invention, simply by pushing the heating punch 29 into the enlarged part 25 of the insert 21, the enlarged part 25 is softened and deformed, and the contact surface 26 presses the magnetic core 1 against the side surface 24 and fixes it.
Since the magnetic core 1 is not subjected to impact due to caulking as in the first conventional example, the magnetic core 1 is not deformed. Also, the side surface 2 of the center part of the insert 21
4 is used as the reference plane A, and only the enlarged portion 25 is softened and the magnetic core is pressed against it, so there is no need for the troublesome process of injecting adhesive as in the second conventional example, and automation is also facilitated. .

[Brief explanation of drawings]

Fig. 1 is a plan view of the first conventional example, and Fig. 2 is a plan view of the first conventional example.
Figure 3 is a cross-sectional view along the line shown in Figure 1.
4 is a plan view of the second conventional example, FIG. 5 is a sectional view taken along the line - in FIG. 4, and FIG. 6 is a plan view of an embodiment using the magnetic core fixing method of the present invention. , FIG. 7 is a sectional view taken along the line - of FIG. 6, FIG. 8 is a sectional view taken along the line - of FIG. 6, and FIG. 9 is a plan view of the insert. 1...Magnetic core, 3...Hold case, 7...
...Magnetic core fitting groove, 8...Inner wall, 10...Outer wall, 12...Recess, 18...Riveting punch, 21
... insert, 22 ... center part, 23 ... side part, 24 ... side surface, 25 ... ampullary part, 26 ... contact surface, 29 ... heating punch.

Claims (1)

[Claims] 1 Consisting of a central part and side parts that are integrally formed with the central part and extend to the sides thereof and have a part of the enlarged part,
Insert an insert made of heat-softening material with the side surface of the center part as a reference plane into the designated position inside the hold case,
placing a magnetic core between the central part and the side part;
By pressing a heating punch against the enlarged portion, the enlarged portion is heated and softened and deformed, and the magnetic core is pressed against the side surface of the central portion that is a reference surface;
A method for fixing a magnetic core of a magnetic head, comprising fixing the magnetic core at a position along the side surface of the central portion.