JP2540135Y2 - Split cylindrical ferrite core - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a split-type cylindrical ferrite core used for preventing high-frequency electromagnetic noise in a signal line connecting electronic equipment with electronic equipment.

[0002]

2. Description of the Related Art Conventionally, in order to suppress electromagnetic noise between signal lines connecting signal lines between devices, as shown in FIG. 3, the impedance of a signal line in which a signal line 2 acts as an antenna is reduced. In order to increase the size, a cylindrical ferrite core 1 is passed through the signal line 2 to prevent radiation of high-frequency electromagnetic noise, thereby forming a data line filter. For the installed signal lines, a split cylindrical ferrite core (hereinafter referred to as a core) consisting of two core split pieces of a semi-cylindrical ferrite core is used, and the core is split by a resin band. The signal line is held in a tubular shape by sandwiching the signal line from both sides by binding the outer periphery of the piece or covering the split type case connected by a hinge.

[0003]

In the case of the conventional semi-cylindrical core segment, a binding band and a case are required, and the binding band has a drawback that it is cumbersome to handle. There is a drawback that it is difficult to perform the operation, and the case has to be made with high dimensional accuracy so that the core divided pieces can be stored in the case. Further, there is a problem that it is not easy to remove the core split piece from the signal line without damaging the binding band and the case, and it is difficult to replace the split cylindrical ferrite core.

[0004]

In order to solve the above-mentioned problems, according to the present invention, a core divided piece is formed into a gutter shape which is divided into two along a cylindrical body axis and provided with a vertical step in the middle. The ferrite magnet magnetized is arranged in contact with its magnetic pole in contact with the step, and the core divided pieces are combined in a cylindrical shape.

[0005]

[Function] The magnetized ferrite magnet connected to the step is
The magnetic attraction force keeps the core split piece cylindrical, and applies a DC magnetic field in the last saturation region to the core split body in the axial direction of the cylindrical body to suppress the movement of the domain wall and to achieve relative permeability characteristics. Loss component at high frequencies. This loss reduction is
A decrease in impedance with respect to a high frequency component is suppressed, and the absolute value of the high frequency characteristic of the impedance is increased.

That is, according to the present invention, a core split body divided into two along a cylinder axis and provided with a vertical step in the middle is provided through a ferrite magnet provided with a magnetic pole in contact with the step. A divided cylindrical ferrite core, wherein divided bodies are combined in a cylindrical shape.

[0007]

FIG. 1A is an external perspective view of one embodiment of a split-type tubular ferrite core according to the present invention. The split cylindrical ferrite core according to the present invention shown in FIG. 1 includes two core split bodies 3 and two (one is shown) ferrite magnets (hereinafter, referred to as magnets) 4. The core divided body 3 (hereinafter referred to as a divided body) has a vertical stepped portion 5 having the same direction along the axis of the cylindrical body having an octagonal cross section and having the same direction as shown in FIG.
(Hereinafter referred to as “step”), and has a gutter shape in which the step 5 is slightly retreated. The magnet 4 is a rectangular parallelepiped, and has a rectangular magnetic pole surface corresponding to the step 5. The interval between the pole faces is about twice the retreat length from the center of the step 5.
The ferrite magnet 4 has a high material specific resistance, and does not generate an eddy current due to a magnetic field generated by a signal current flowing through a signal line, that is, a material that does not generate a loss. The two magnets 4 are disposed on the stepped portion 5 of the first core segment 3 with the magnetic pole surfaces in contact with the magnetic poles in the same or opposite directions.
One of the divided bodies 3 is arranged under the signal line (not shown) through the signal line in the central groove, and the second divided body 3 is combined with the magnetic pole surface of the magnet 4 so as to face the step 5. As shown in FIG. 1A, a divided cylindrical ferrite core in which the end faces of the divided body 3 are substantially flush is formed by the magnetic attraction force of the magnet 4. In principle, even if there is only one step 5 in the split body 3, it can be held in a cylindrical shape, but it is not practical because it cannot be firmly held, and ferrite magnets are arranged on both sides of the core split body. Further, it is not preferable in that the application of the DC magnetic field is local. The material of the divided body 3 has a saturation magnetic flux density of 30.
In the case of a nickel-based ferrite material of 00 gauss, the magnet 4 has a magnetization strength of about 500 gauss and has the best high-frequency radiation noise prevention ability.

FIG. 2 is an exploded perspective view of another embodiment of the present invention. The core split body 6 of this embodiment has two step portions 5.
Are formed in the opposite direction. As described above, the magnet 4 (indicated by a chain line) is disposed on the step portion 5 in the same direction as the magnetic pole and parallel to the axis, and assembled into a split-type cylindrical ferrite core. The core divided body 6 has an advantage that the size of the magnet 4 for making the end face flush with the cylindrical shape can be easily recognized. Although the present invention has been described with an example in which the core divided body is assembled with two magnets, the core divided body is more firmly fixed by using a total of four magnets, one at each end of the core divided body. You can do it.

[0009]

The present invention is configured as described above, and has the following effects. Since it is held in a cylindrical shape by the magnetic attraction of the magnet, it is easy to mount it on the signal line. Also, it can be easily removed from the signal line.
Since a member for holding the tube is not required, material costs can be reduced, and removal and replacement can be performed without waste. By applying a DC magnetic field in the axial direction of the cylindrical body by the magnet, the effect of attenuating high-frequency electromagnetic noise as a data line is enhanced.

[Brief description of the drawings]

1 is an external perspective view showing an embodiment of a split type cylindrical ferrite core according to the present invention, wherein FIG. 1 (a) is a completed perspective view, and FIG. 1 (b) is an exploded perspective view.

FIG. 2 is an exploded perspective view showing another embodiment of the present invention.

FIG. 3 is a perspective view showing a conventional non-split type ferrite core attached to a signal line.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylindrical ferrite core 2 Signal line 3 Core division body 4 Ferrite magnet 5 Vertical step part 6 Core division body

Claims (1)

(57) [Scope of request for utility model registration] 1. A core split body which is divided into two along a cylindrical body axis and provided with a vertical step in the middle, and a core split through a ferrite magnet which is disposed with a magnetic pole in contact with the step. A split type cylindrical ferrite core characterized by being combined in a cylindrical shape.