JPH0240111A - Manufacture of magnetic head core - Google Patents

Abstract

PURPOSE:To prevent breakage of a head core gap molding part from being generated by burr in grinding after sintering by mounting grooves on both planes of the gap molding part in the powder compressing of a head core. CONSTITUTION:The groove (c) with width of 3mm and depth of 0.2mm is formed at the gap molding part (b) cut and formed after the sintering at the time of performing the powder compressing of a magnetic head. The burr with around 0.1mm is protruded on the gap molding part (b), however, it is protruded from the bottom of the groove, therefore, it is not protruded over the setting plane (d) of a magnetic table to a magnetic chuck. In such a way, it is possible to prevent the formation of the breakage at the gap molding part due to the influence of the burr, therefore, to obtain the magnetic head core with superior yield and manufactured inexpensively.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention [Field of Industrial Application] The present invention relates to a method of manufacturing an erasing magnetic head core used in an audio magnetic recording device.

[Conventional technology]

Conventionally, the manufacturing method of a magnetic head core for erasing (hereinafter referred to as a head core) usually uses Mn-Zn ferrite core powder, and as shown in FIGS. The powder is press-molded into an annular shape, sintered, and then ground at the grinding allowance f shown in Figure 1 (B), and cut from the part g shown in Figure 1 (A) to form the desired shape. The shape was realized.

[Problem to be solved by the invention]

In the powder press molding of the head core shown in Figure 1, burrs are generated in the gap formed part of the head core, and when the sintered head core is set in the magnetic chuck during the thickness polishing process after sintering, the magnetic force This caused the problem that the edge part flew off and was damaged, and the gap molding part was chipped, making it unusable for the head core.

1. Structure of the invention [Means for solving the problems] In order to solve these problems, the present invention is such that grooves are attached during press molding to both sides of the gap molded part of the head core where flashing occurs. Even if burr occurs during powder press molding, it will occur at the bottom of the groove, so even if it is attached directly to the magnetic chuck for grinding the surface after sintering,
The particles do not come into contact with the suction surface of the magnetic chuck, which prevents chipping of the void forming part.

That is, in the present invention, during powder press molding of a magnetic head core, a groove with a step is provided from both sides is attached to the gap molded part that is cut and formed after sintering, and after sintering, both sides are ground and the gap molded part is cut and formed. This is a method of manufacturing a magnetic head core characterized by the following.

[Effect]

In the powder press molding of the head core, the present invention can prevent the head core cavity molding part from chipping due to burr during grinding after sintering by providing grooves on both sides of the cavity molding part.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 2 shows a conventional head core manufacturing method. As shown in Figure 2 (A), the head core was powder pressed and sintered, and as shown in Figure 2 (B), both sides, which are the surfaces d to be set on the magnetic table, were polished to a thickness. , a head core with a finished thickness of e was obtained, but the burr generated in the gap forming part shown in Figure 2 (A) during powder press molding was set in a magnetic chuck during the thickness polishing process after sintering. When the head core protrudes from both sides (setting surface d) of the magnetic table, it is attracted by the magnetic force of the magnetic chuck and damaged, causing a chip in the gap molding part when used as a head core, resulting in an unusable product. was.

FIG. 1 is a diagram for explaining the shape of the head core of the present invention.

The whole of FIG. 1 shows a product after powder press molding, and grooves are formed in the form of steps on both sides of the press molded head core cavity molded part.

This groove will be formed at the bottom of the groove even if burr occurs in the gap molding, and will prevent contact between the magnetic chuck and burr when the head core is set on the magnetic chuck during the thickness polishing process after sintering. Therefore, it is possible to prevent chipping that occurs in the gap molded portion when forming the head core due to the influence of the cracks. The grooves on both sides provided in the gap molding portion of the head core are ground down by thickness polishing to a final thickness e.

Next, one embodiment of the present invention will be described.

As shown in Figure 1, the overall shape of the powder press-molded product has a groove C with a width of 3111 m and a depth of 0.2 mm.
I added. The hole protruded from the gap molding part by about 0.1 mm, but since it protruded from the bottom of the groove, it did not protrude from the set surface d of the magnetic table to the magnetic chuck.
To prevent chipping of the void molded part due to the influence of paris, both sides are ground by 0.3 mm each, resulting in a finished thickness e.
was gotten.

As described above, the manufacturing method of the present invention prevents chipping of the head core cavity molding part, thereby making it possible to provide a head core with stable quality.In addition, it is possible to prevent the occurrence of defective products due to chipping, and to improve the yield, resulting in inexpensive magnetic Head cores can now be provided.

In the embodiments of the present invention, a method for manufacturing an erasing magnetic head core has been described, but it can also be applied to a method for producing other recording/reproducing magnetic head cores made by press-molding powder. The present invention is not limited to manufacturing magnetic head cores.

Effects of the Invention According to the present invention, it is possible to prevent the occurrence of chipping that occurs in the gap molding part of the erasing magnetic head core, and it is possible to create a magnetic head core that is highly reliable and has an improved manufacturing yield, resulting in an inexpensive magnetic head core. can be provided.

[Brief explanation of the drawing]

FIG. 1 is a view of a powder press-molded product of an erasing magnetic head core according to the present invention, in which (A) is a plan view and (B) is a side view. FIG. 2 is a diagram of a powder press-molded product of a conventional erasing magnetic head core, in which (A) is a plan view and (B) is a side view. Margin C below: Magnetic head core for erasing. ...Gap forming part. ···groove. ...Set surface on magnetic table. ... Finished thickness dimension. ...Grinding cost. ...cut section.

Claims (1)

[Claims] 1. At the time of powder press molding of the magnetic head core, grooves with steps are attached from both sides to the void molded part that is cut and formed after sintering, and after sintering, both sides are ground and the void molded part is cut and formed. A manufacturing method for a featured magnetic head core.