JPH04329609A - Ferrite magnetic core - Google Patents

Abstract

PURPOSE:To reduce a leakage magnetic flux, by making one of both magnetic cores placed in a butted part a protruded part and making the other magnetic core, a recessed part, and by inserting the protruded part into the recessed part, and by providing tapered surfaces on the protruded and recessed part, and further, by making the formation angles or curvatures of both the tapered surfaces equal to each other. CONSTITUTION:A ferrite magnetic core comprises two E-shaped ferrite magnetic cores 1, 2, whose central legs 3, 4 are both cylindrical. The end of the central leg 3 is made to be a cone-like recessed part 5, and the end of the central leg 4 is made to be a cone-like protruded part 6. The formation angles of the cone-like parts of the respective central legs 3, 4 are made equal to each other. Thus, in the gap part between both the cone-like parts, the central leg 4 is inserted into the central leg 3, and therefore, the leakage magnetic flux of the ferrite magnetic core is made less. Also, by adjusting the length of the gap, a desired DC superposition characteristic can be obtained. Further, since the ends of the recessed and protruded part are both pointed, they can be cut satisfactorily.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ferrite magnetic core used in choke coils, transformers, etc.

0002

2. Description of the Related Art Conventionally, two E-type ferrite magnetic cores have been used, abutted against each other to form a closed magnetic circuit, and a coil has been applied to this to form a choke or a transformer.

[0003] In this conventional choke and transformer, a gap is formed between two E-type ferrite magnetic cores where they abut against each other, thereby obtaining the necessary direct current superposition characteristics. A front view of this conventional ferrite magnetic core is shown in FIG. This conventional example uses two E-type ferrite magnetic cores 61 and 62, and the center leg 63 of one E-type ferrite magnetic core 62 is formed shorter than both outer legs 64, thereby forming a gap 65.

0004

[Problems to be Solved by the Invention] In the conventional ferrite magnetic core, leakage magnetic flux is generated from the gap 65 portion, and this leakage magnetic flux interlinks with the coil, causing heat generation, causing a choke,
This had a negative effect on the reliability of the transformer.

[0005] Therefore, a ferrite magnetic core with low leakage flux has been required.

In view of the above, an object of the present invention is to provide a ferrite magnetic core with low leakage flux.

[0007]

[Means for Solving the Problems] The present invention provides at least two
In a ferrite magnetic core in which two magnetic cores are abutted against each other and a gap is formed in the abutted portion, one of the cores of the abutted portion is formed in a convex shape, the other magnetic core is formed in a concave shape, and the convex portion is inserted into the concave portion, and the convex portion and the concave portion each have a tapered surface, and the forming angle or curvature of the tapered surface is the same.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a perspective view of an embodiment of the present invention, and FIG. 2 is a sectional view thereof. This embodiment consists of two E-type ferrite magnetic cores 1 and 2, the center legs 3 and 4 are cylindrical, the tip of one center leg 3 is formed with a conical recess 5, and the center of the other A conical convex portion 6 is formed at the tip of the leg 4. The conical portions at the tips of each of the center legs 3 and 4 are formed at the same angle.

FIG. 3 shows an exploded perspective view of a second embodiment of the present invention, and FIG. 4 shows a sectional view thereof. This embodiment consists of two E-type ferrite magnetic cores 11, 12, a central leg 13,
Reference numeral 14 has a prismatic shape, and a pyramid-shaped concave portion 15 is formed at the tip of one center leg 13, and a pyramid-shaped convex portion 16 is formed at the tip of the other center leg 14. The taper angle of the pyramid-shaped concave portion 15 at the tip of one center leg 13 and the pyramid-shaped convex portion 16 at the tip of the other center leg 14
The taper angles of the two are formed to be the same.

FIG. 5 shows a sectional view of the central leg portion of a third embodiment of the present invention. In this embodiment, one center leg 2
A concave-shaped recess 23 is formed in the other center leg 2.
2, a cone-shaped convex portion 24 is formed. and,
Each conical taper portion is formed at the same angle.

FIG. 6 shows a sectional view of the central leg portion of a fourth embodiment of the present invention. In this embodiment, one center leg 3
1 is formed with a spherical recess 33, and the other center leg 32 is formed with a spherical recess 33.
A spherical convex portion 34 is formed on both sides, and the curvatures of the spherical surfaces are the same.

According to the embodiment of the present invention, the gap portions are structured so that one side is inserted into the other, and leakage magnetic flux is extremely reduced. Further, by adjusting the gap interval, desired DC superimposition characteristics can be obtained. Furthermore, since the tips of the concave and convex portions have acute angles, they may be cut.

[0013]

According to the present invention, leakage magnetic flux at the gap portion can be extremely reduced, and heat generation in the coil due to the leakage magnetic flux can be prevented. Therefore, the reliability of the choke and transformer can be improved.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an embodiment according to the present invention.

FIG. 2 is a sectional view of an embodiment according to the present invention.

FIG. 3 is an exploded perspective view of a second embodiment of the present invention.

FIG. 4 is a sectional view of a second embodiment of the present invention.

FIG. 5 is a sectional view of the central leg portion of a third embodiment of the present invention.

FIG. 6 is a sectional view of a central leg portion of a fourth embodiment of the present invention.

FIG. 7 is a perspective view of a conventional example.

[Explanation of symbols]

1, 2, 11, 12 E-type ferrite core 3, 4, 1
3, 14, 21, 22, 31, 32 Center legs 5, 15
, 23, 33 Concave portion 6, 16, 24, 34 Convex portion

Claims (1)

[Claims] 1. A ferrite magnetic core comprising at least two magnetic cores butted against each other and a gap formed in the abutted portion, one of the cores of the abutting portion having a convex shape, and the other core having a concave shape. wherein the convex portion is inserted into the concave portion, the convex portion and the concave portion each have a tapered surface, and the forming angle or curvature of the tapered surface is the same. ferrite magnetic core.