JPH05299253A - Magnetic device - Google Patents

Abstract

PURPOSE:To eliminate a leakage flux in a magnetic device, such as a coil, a transformer or a choke coil. CONSTITUTION:Windings 2 and 3 are wound on a magnetic core 1, which forms a closed magnetic circuit, and an addition magnetic piece 12 is connected to the core 1 in such a way as to cover each one part of these windings. When a current flows through the windings 2 and 3, a leakage flux which leaks from the core 1 is absorbed by the piece 12 to shunt the magnetic circuit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic device used as a coil, a transformer or a choke coil.

[0002]

2. Description of the Related Art FIG. 4 is a perspective view showing a conventional magnetic device used as a choke coil, for example. In the figure, 1 is a toroidal magnetic core, 2 and 3 are windings wound around the magnetic core 1, and 4 is a leakage magnetic flux.

In the above magnetic device, a current flows through the winding 2 or 3 to form a closed magnetic circuit inside the magnetic core 1. However, a part of the magnetic flux leaks out of the magnetic core 1 and leaks. A magnetic flux 4 is formed.

[0004]

In the conventional magnetic device as described above, since the leakage magnetic flux adversely affects peripheral devices and the like such as magnetic interference, there is a strong demand for a magnetic device having no leakage magnetic flux.

The present invention has been made to solve such conventional problems, and an object thereof is to obtain a magnetic device having no leakage magnetic flux.

[0006]

The present invention is the following magnetic device. (1) Magnetic property including a magnetic core forming a closed magnetic path, a winding wound around the magnetic core, and an additional magnetic piece connected to the magnetic core so as to cover at least a part of the winding. device. (2) A magnetic core having a convex portion, a winding wound around a portion without the convex portion, and an additional magnetic piece connected to the convex portion so as to cover at least a part of the winding. The magnetic device according to (1) above. (3) The magnetic device according to (1) or (2) above, wherein the additional magnetic piece has an insertion hole for the winding.

[0007]

In the magnetic device of the present invention, when a current flows through the winding, a closed magnetic circuit is formed in the magnetic core. At this time, the magnetic flux leaking from the magnetic core is absorbed by the additional magnetic piece and shunts. .. This suppresses the leakage of magnetic flux from the magnetic device.

When the convex portion is formed on the magnetic core, the magnetic core and the additional magnetic piece can be connected easily and securely, and the absorption of the leakage magnetic flux is improved.

If the additional magnetic piece is provided with a through hole for the winding, the end portion of the winding can be easily fixed, and the end of the winding can be used as it is as a lead wire.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. Example 1 FIG. 1 is an exploded perspective view showing a magnetic device of Example 1, FIG.
FIG. 4 is a perspective view showing its assembled state, and in FIG.
The same reference numerals denote the same or corresponding parts.

The magnetic device of this embodiment shows an example in which it is used as a choke coil. The magnetic core 1 has a toroidal shape, and each of the magnetic cores 1 protrudes to the upper and lower sides of its side surface.
A pair of convex portions 11 is formed. The windings 2 and 3 are wound around a portion of the magnetic core 1 that does not have the protrusion 11. Reference numeral 12 denotes an additional magnetic piece, which is brought into contact with the convex portion 11 to be magnetically connected to the winding 2,
It is laminated so as to cover the side surface portion of No. 3.

In the above magnetic device, the winding 2,
When a current flows through the magnetic core 3, a closed magnetic circuit is formed in the magnetic core 1. At this time, the leakage magnetic flux 4 leaking from the magnetic core 1 is absorbed by the additional magnetic piece 12 and shunts. This suppresses the leakage of magnetic flux from the magnetic device.

At this time, the leakage magnetic flux 4 can be absorbed even without the convex portion 11, but by providing the convex portion 11 and adhering the additional magnetic piece, the magnetic connection becomes good,
The absorption effect is high. Instead of the convex portion 11, another magnetic piece may be interposed.

The magnetic device of the above embodiment is a choke coil. When this is used as a common mode choke coil, the attenuation of the normal mode noise depends on the leakage inductance, so the additional magnetic piece 12 is used.
As a result, the leakage inductance increases, and the noise removal effect also increases.

In this case, by changing the magnetic characteristics of the magnetic core 1 and the additional magnetic piece, it is possible to control the effect of absorbing leakage magnetic flux and the effect of removing noise.

The above magnetic device can be applied not only to the choke coil but also to general coils and transformers, and can similarly prevent magnetic flux leakage.

Embodiment 2 FIG. 2 is a perspective view showing a magnetic device of an embodiment. In this embodiment, one additional magnetic piece 12 is provided with insertion holes 13 for the windings 2 and 3, and the end portions 2a, 2b, 3 of the windings 2 and 3 are provided.
The configuration is the same as that of the first embodiment except that a and 3b are inserted and fixed.

In this embodiment, like the first embodiment, leakage of magnetic flux from the magnetic device can be suppressed, and the insertion hole 13
This facilitates fixing of the end portions 2a, 2b, 3a, 3b of the windings 2 and 3, and the end portion of the winding can be used as it is as a lead wire.

In the above first and second embodiments, the example of the choke coil has been described, but it can be used for other magnetic devices such as a coil or a transformer, and leakage magnetic flux can be prevented. The shape of the magnetic core 1 is not limited to the toroidal shape, and may be another shape such as an EI type or a UU type. Further, although the disk-shaped additional magnetic piece 12 is shown, the additional magnetic piece 12 may have a ring shape or the like according to the side surface shape of the magnetic core 1.

[0020]

As described above, according to the magnetic device of claim 1 of the present invention, since the additional magnetic piece is connected to the magnetic core so as to cover at least a part of the winding, the magnetic flux leaking from the magnetic core. Can be absorbed and shunted by the additional magnetic piece, and thus the leakage magnetic flux from the magnetic device can be suppressed.

According to the second aspect of the invention, since the convex portion is provided on the magnetic core, the additional magnetic piece can be magnetically connected to the magnetic core easily and reliably. Further, according to the invention of claim 3, the end of the winding is easily fixed by the insertion hole of the additional magnetic piece, and this end can be used as it is as a lead wire.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a magnetic device of Example 1. FIG.

FIG. 2 is a perspective view showing an assembled state of FIG.

FIG. 3 is a perspective view showing a magnetic device of Example 2.

FIG. 4 is a perspective view showing a conventional magnetic device.

[Explanation of symbols]

 1 Magnetic Core 2, 3 Winding 11 Convex 12 Additional Magnetic Piece 13 Insertion Hole

Claims (3)

[Claims] 1. A magnetic core that forms a closed magnetic circuit, a winding wound around the magnetic core, and an additional magnetic piece connected to the magnetic core so as to cover at least a part of the winding. A magnetic device characterized by that. 2. A magnetic core having a convex portion, a winding wound around the portion without the convex portion, and an additional magnetic piece connected to the convex portion so as to cover at least a part of the winding. The magnetic device according to claim 1, further comprising: 3. The magnetic device according to claim 1, wherein the additional magnetic piece has an insertion hole for a winding.