JPS6366409B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for manufacturing a ferrite core used as a transformer.

Structure of conventional example and its problems A ferrite core is produced by molding a material made of iron oxide or the like in a mold, then firing, cutting, polishing, etc. Therefore, if there are variations in the molding density, the size of the shrinkage will be uneven during firing, resulting in deformation such as warping. For example, in the case of the EI type core shown in Fig. 1, if the E type core 1 and the I type core 2 are molded and fired separately, the outer magnetic legs 1a and 1b of the E type core 1 will warp outward or inward. In addition, the I-type core 2 also warps. For this reason, conventionally, E-type core 1 and I-type core 2
are integrally molded into a Japanese character shape, fired, and then cut into an E-type core 1 and an I-type core 2. Furthermore, the abutting surfaces of each core 1 and 2 are polished to eliminate unevenness and make them flat. I was gone. Since ferrite is hard and brittle, such cutting and polishing results in poor yields and requires many man-hours, resulting in an increase in costs.

OBJECTS OF THE INVENTION In view of the above-mentioned drawbacks, the present invention provides a method for manufacturing a ferrite core that reduces the number of man-hours required to process the ferrite core and can manufacture an inexpensive core.

Structure of the Invention In order to achieve the above object, the present invention provides a groove at the tip of the outer magnetic leg of an E-type core or a U-type core,
A protrusion is provided on the abutting surface of the I-shaped core, and after the E-shaped core or U-shaped core and the I-shaped core are fired in abutted state, the E-shaped core or U-shaped core and the I-shaped core are separated. .

Since the projections of the I-type core are fitted into the grooves of the E-type core or U-type core and then fired, there is no warping of each core, and even when the cores are separated and reassembled, there are very few irregularities on the mating surfaces and there is no misalignment. Since there is no need for cutting or polishing, processing steps such as cutting and polishing can be omitted, resulting in improved yields and lower manufacturing costs.

DESCRIPTION OF EMBODIMENTS A method for manufacturing a ferrite core according to an embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 2, the outer magnetic legs 3 of the E-type core 3
Grooves 5a and 5b are provided at the tips of a and 3b, that is, the abutting surfaces with the I-type core 4, and grooves 5a and 5b are provided in the I-type core 4 at positions corresponding to the grooves 5a and 5b of the E-type core 3. Protrusions 6a and 6b are provided so as to be able to fit into them. These grooves 5a, 5b and protrusions 6a, 6b
can be provided at the stage of molding the cores 3 and 4.
Further, the E-type core 3 and the I-type core 4 are molded separately. The core thus formed is fired with the grooves 5a, 5b and the protrusions 6a, 6b fitted together, as shown in FIG. Usually, the E-shaped core 3 and the I-shaped core 4 are pressed while being in close contact with each other because they are stacked in many layers and fired. In addition, since the E-type core 3 and the I-type core 4 are fitted, the outer magnetic leg 3 of the E-type core 3
a, 3b do not bend outward or inward, and the I-shaped core 4 can be fired with less warpage. Furthermore, since the cores 3 and 4 manufactured by the method of this embodiment have a small gap on the abutting surfaces, they can be used as cores for transformers and the like with large inductance. Furthermore, as shown in FIG. 4, if the I-shaped core 4 is turned over and used, it can be used as a core of a transformer or a chain yoke with a gear spacer 7 inserted in the abutting surface. Furthermore, as shown in Figure 5,
If a gap 9 is provided on the opposite side of the I-type core 8 to the side facing the central magnetic leg of the E-type core and manufactured by the method of this embodiment, a core with a gap can be used as a transformer or a chain yoke. It can be used for.

As shown in FIG. 6, the present invention has similar effects even with a UI type core consisting of a U-shaped core 9 provided with grooves 9a and 9b and an I-shaped core provided with protrusions 10a and 10b.

Effects of the Invention As described above, the present invention provides grooves at the tips of the outer magnetic legs of the E-type core or U-type core, and protrusions on the abutting surfaces of the I-type core, so that the E-type core or U-type core By firing the mold cores against each other, there is no warpage in the cores during firing, and even when they are separated and recombined, there are very few irregularities and no deviations, so steps can be eliminated, yields are high, and costs are low. cores can be manufactured.

[Brief explanation of drawings]

Figure 1 is an exploded perspective view of a conventional ferrite core.
FIG. 2 is an exploded perspective view of a ferrite core manufactured by a method for manufacturing a ferrite core according to an embodiment of the present invention, and FIG. 3 is a front view of the same ferrite core.
Fig. 4 is a front view of the same ferrite core with a gear spacer inserted therein, and Fig. 5 is a front view of the same ferrite core with a gap provided in the I-shaped core.
FIG. 6 is an exploded perspective view of a UI type ferrite core manufactured by a ferrite core manufacturing method according to another embodiment of the present invention. 3...E-type core, 3a, 3b...outer magnetic legs,
4, 8, 10...I type core, 5a, 5b, 9a,
9b...Groove, 6a, 6b, 10a, 10b...Protrusion.

Claims (1)

[Claims] 1 A groove is provided at the tip of the outer magnetic leg of the E-type core or U-type core, and a protrusion that fits into the groove is provided at a position corresponding to the groove in the I-type core, and the E-type core or U-type core and the I-shaped core are fired in a state where they are fitted with the groove and the protrusion, and then the E-shaped core or the U-shaped core and the I-shaped core are separated.