JPH0614434Y2 - Common mode coil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a common mode coil to be inserted into a signal line or a power line in order to suppress electromagnetic noise.

[Conventional technology]

Conventionally, the common mode coil that has been inserted into the signal line or power line to suppress electromagnetic noise is made by winding two windings in the same direction around an annular magnetic core (toroidal core) or UU type or EE type magnetic core. ing.

[Problems to be solved by the invention]

The conventional common mode coil using the toroidal core has a drawback that the winding work is complicated and the number of man-hours cannot be reduced because two windings are manually performed or a toroidal winding machine is required. On the other hand, the common mode coil of the noise filter used for the purpose of removing electromagnetic noise in the high frequency band does not require many windings. Therefore, the common mode coil according to the present invention aims at removing such electromagnetic noise in the high frequency band. The ferrite core is provided with a plurality of grooves, the plate-shaped ferrite core is opposed to the grooved ferrite core to form a through hole, and a plate of a good conductive material is punched out or formed into a meandering shape by etching. By providing the lead frame in the groove, it is possible to provide a small-sized and inexpensive common mode coil without providing complicated windings.

[Means for solving problems]

In order to solve the above-mentioned problems, in the present invention, a ferrite core having a plurality of grooves formed at a predetermined pitch on two opposing surfaces, and a plate-shaped core on the two surfaces having the grooves are provided. Two meandering lead frames are housed in a through hole formed by abutting each other, and a common mode coil is formed by a structure in which a conductor sequentially penetrates the through hole of the core.

That is, the present invention is: Prepare a ferrite core with high magnetic permeability characteristics, which is provided with two equal numbers of grooves at equal intervals at a given pitch.
A lead frame which is meandering in the groove and which fits in the groove is housed, and the two surfaces provided with the groove are covered with a ferrite plate having high magnetic permeability characteristics, respectively, and abutted, and the end surfaces are adhered to each other. A common mode coil.

2. The interval between adjacent grooves provided on both sides of the ferrite core and the interval between the opposing grooves are the same length, and the interval between the grooves in contact with both end surfaces and the end surface, and the thickness of the ferrite plate to be fitted to each groove are:
The common mode coil according to claim 1, wherein the length is half the groove interval.

[Explanation by Examples]

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

FIG. 2 is a ferrite core having a plurality of grooves on two opposite surfaces, and FIG. 3 is a lead frame having a meandering shape.
The drawing shows a common mode coil according to the present invention.

In the figure, a ferrite core 1 is a rectangular core and has the same number of grooves 2 on both opposite sides, and the grooves 2 are formed at a constant pitch in parallel with the lateral lines. The lead frame 3 shown in FIG. 3 is formed by precision punching, etching or the like of a thin thin metal plate of brass, beryllium copper, stainless steel, or an alloy thereof having good elasticity and good conductivity. It has a meandering shape a plurality of times and has a terminal piece 4 at the end.
The lead core 3 is inserted into the ferrite core 1 along the groove 2 in such a direction that the magnetic fields generated by the currents flowing through the lead frames 3 cancel each other. Further, after mounting the lead frame 3, the plate-shaped ferrite core 5 is placed along both sides of the ferrite core 1 facing each other, and the adhesive 6 is applied and fixed so that the ferrite core 1 and the plate-shaped ferrite core 5 are not displaced, and the common. The mode coil is completed.

In forming the common mode coil of the present invention, the core size and groove interval for obtaining the most efficient magnetic velocity distribution, that is, the inductance, are shown in FIG. The groove interval b is equal, the interval c between the end face and the groove and the plate thickness d of the plate-shaped ferrite core 5 covering the groove shown in FIG. 1 have the same value, and a = b = 2c = 2d.

[Effect of device]

As is clear from the above description, since the common mode coil according to the present invention is easy to handle and has a simple structure, a general-purpose automated machine can be used for manufacturing the common mode coil, and automation equipment cost can be reduced. Therefore, it is cheap due to automation,
Moreover, an automatic mounting machine can be used to provide a common mode coil that is easy to manufacture.

[Brief description of drawings]

FIG. 1 is an external perspective view showing an example of a common mode coil according to the present invention. FIG. 2 is a perspective view of a ferrite core having the same number of grooves facing each other on opposite surfaces. FIG. 3 is a perspective view showing the shape of a lead frame forming a conductive wire. 1 ... Ferrite core. 2 ... groove. 3 ... Lead frame. 4 ... Terminal piece. 5: Plate-shaped ferrite core. 6 ... Adhesive.

Claims (2)

[Scope of utility model registration request] 1. A ferrite core having a high magnetic permeability characteristic, in which equal number of grooves at equal intervals are provided on two opposing surfaces at a predetermined pitch, and a lead having a meandering shape is inserted into the groove. A common mode coil characterized in that it is formed by housing a frame, covering two grooves provided with a ferrite plate having a high magnetic permeability property, butting them together, and adhering the end faces. 2. An interval between adjacent grooves provided on both sides of the ferrite core and an interval between the opposing grooves are set to be the same length, and an interval between the grooves contacting both end faces and the end face and a plate thickness of the ferrite plate to be fitted to the grooves are an interval between the grooves. 2. The common mode coil according to claim 1, which has a length of 1/2.