JPH0520312U - Electromagnetic device for noise filter - Google Patents

Abstract

(57) [Abstract] [Purpose] Insulation of a pair of winding wires with a simple structure at low cost. [Structure] A cylindrical low-frequency Mn-Zn ferrite magnetic core 1 and vertical holes 2 and 3 penetrating therethrough are inserted and arranged in the cylinder of the low-frequency Mn-Zn ferrite magnetic core 1 with a gap left between them. And a columnar Ni-Zn ferrite magnetic core 4 for high frequency are provided, and the windings 6 and 7 are separately wound on one side and the other side of the Mn-Zn ferrite magnetic core 1 for low frequency and used for high frequency. The Ni-Zn ferrite magnetic core 4 was inserted into the vertical holes 2 and 3, respectively. [Effects] High-frequency Ni-Zn ferrite magnet having an insulating property between the windings 6 and 7 that are separately wound on one side and the other side of the low-frequency Mn-Zn ferrite magnetic core 1 having an insulating property. Since the core 4 is interposed, high-frequency Ni-
The Zn ferrite magnetic core 4 serves as a partitioning member for the windings 6 and 7, so that insulation between the windings 6 and 7 can be achieved, and no special member for insulating between the windings 6 and 7 is required. The configuration is simple and inexpensive.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a noise filter electromagnetic device such as a common mode noise filter (inductor) which is a noise countermeasure component of an electronic device.

[0002]

[Prior Art]

 Noise filters are often used as EMC countermeasure components, but noise generated by electronic devices contains wide harmonic components, so broadband filter effects are required. However, at present, Mn-Zn ferrite material is used as the core material, and its magnetic permeability is limited to about 2 MHz. In a band higher than that, in order to obtain a noise reduction effect, a noise filter using a Ni—Zn ferrite material as a high frequency ferrite material is also used to reduce the noise.

However, the use of two types of noise filters for low frequency and high frequency is contrary to the trend of miniaturization and thinning, but one noise filter electromagnetic device has a noise reduction effect over a wide frequency band. Are required. As one idea to meet such requirements, as shown in FIG. 3, two kinds of magnetic cores made of different materials, for example, a low frequency ferrite core 11 made of Mn-Zn ferrite material and a Ni-Zn ferrite magnet are used. A high frequency ferrite magnetic core 12 made of a core is formed concentrically to form a composite magnetic core 13, and a noise filter electromagnetic device in which a winding (not shown) is applied to the composite magnetic core 13 has already been proposed. ing.

Among such noise filters, there is a common mode noise filter including a noise filter electromagnetic device in which a pair of windings are wound around one composite magnetic core. In such a common mode noise filter having two windings, it is important to improve the insulation between the pair of windings. Most of the ideas for improving insulation between a pair of windings are due to the shape of the core case.

As one idea, as shown in FIG. 4 (see Japanese Utility Model Laid-Open No. 2-84305), in an insulating cylindrical core case 21 having a central hole, a partition made of an insulating plastic is provided in the central hole 22. A common mode choke coil has been proposed in which a plate 23 is provided and a pair of windings 24 and 25 are separated and wound. This is to improve the insulation by using the tubular core case 21 and the partition plate 23.

[0006]

[Problems to be solved by the device]

 However, as shown in FIG. 4, when the tubular core case 21 is devised to insulate the pair of windings 24, 25 from each other, the tubular core case 21 is provided with a partition plate 23 for insulation. There was a problem that it became complicated and expensive. Therefore, an object of the present invention is to provide an electromagnetic device for a noise filter which has a simple structure and can inexpensively insulate a pair of windings.

[0007]

[Means for Solving the Problems]

 The electromagnetic device for a noise filter according to the present invention has a pair of vertical holes penetrating the tubular low frequency ferrite magnetic core and is inserted and arranged in a state in which a gap is formed inside the low frequency ferrite magnetic core. A composite magnetic core is composed of a columnar high-frequency ferrite core, and a pair of windings are separated and wound on one side and the other side of the low-frequency ferrite core, respectively. It is inserted into each of the pair of vertical holes.

[0008]

[Action]

 According to the configuration of the present invention, since the columnar high frequency ferrite magnetic core is inserted and arranged inside the tubular low frequency ferrite magnetic core, one of the insulating low frequency ferrite magnetic cores is provided. The insulating high-frequency ferrite core is interposed between the pair of windings that are separately wound on one side and the other side, and the high-frequency ferrite core separates the pair of windings. It becomes a member and can insulate the pair of windings.

[0009]

Embodiment An embodiment of the present invention will be described with reference to FIGS. 1 and 2. As shown in FIGS. 1A to 1C, this noise filter electromagnetic device has a cylindrical low frequency ferrite magnetic core 1 and a pair of vertical holes 2 and 3 penetrating therethrough. A composite magnetic core 5 is constituted by a cylindrical high-frequency ferrite magnetic core 4 which is inserted and arranged in the cylinder of the ferrite magnetic core 1 with a gap for winding the winding open, and a pair of windings 6 and 7 is formed. The low frequency ferrite magnetic core 1 was separated into one side and the other side and wound several turns respectively, and also inserted into the pair of vertical holes 2 and 3 of the high frequency ferrite magnetic core 4 (one turn winding). It is a thing.

In this case, for example, as shown in FIG. 1A, the assembly is performed by inserting the pair of windings 6 and 7 into the pair of vertical holes 2 and 3 of the high frequency ferrite magnetic core 4 and then, as shown in FIG. As shown in (b), a pair of windings 6 and 7 penetrating the pair of vertical holes 2 and 3 are wound around one side and the other side of the low-frequency ferrite magnetic core 1, respectively. As shown in c), the high frequency ferrite core 4 is inserted into the cylinder of the low frequency ferrite core 1 to complete the process.

The low frequency ferrite magnetic core 1 is made of an Mn-Zn ferrite material and has a magnetic permeability in a low frequency region as shown by a curve B in the characteristic diagram showing the frequency characteristic of magnetic permeability in FIG. The low frequency ferrite magnetic core 1 and the pair of windings 6 and 7 form a low frequency common mode noise filter choke coil. Further, the high frequency ferrite magnetic core 4 is made of a Ni—Zn ferrite material and has a constant magnetic permeability from a low frequency region to a high frequency region as shown by a curve A in the characteristic diagram of FIG. The ferrite core 4 and the pair of windings 6 and 7 form a choke coil for a high frequency common mode noise filter. The low frequency ferrite magnetic core 1 and the high frequency ferrite magnetic core 4 are set to have the same height.

Since a pair of windings 6 and 7 are wound or inserted in a state where the ferrite core 4 for high frequency is inserted and arranged inside the cylinder of the ferrite core 1 for low frequency, it can be seen as a whole. For example, the low-frequency ferrite magnetic core 1 and the high-frequency ferrite magnetic core 4 become a composite magnetic core 5 having a magnetic permeability over both low frequency and high frequency, and the composite magnetic core 5 is wound with a pair of windings 6 and 7. The above-mentioned one forms a common mode choke coil having a noise reducing effect over a wide band.

Further, since the columnar high frequency ferrite magnetic core 4 is inserted and arranged inside the cylindrical low frequency ferrite magnetic core 1, one side of the insulating low frequency ferrite magnetic core 1 is disposed. And the insulating high frequency ferrite magnetic core 4 is interposed between the pair of windings 6 and 7 which are separately wound on the other side, and the high frequency ferrite magnetic core 4 is a pair of windings. It serves as a partition member for the coils 6 and 7, and can insulate the pair of windings 6 and 7.

[0014]

[Effect of the device]

 According to the electromagnetic device for a noise filter of the present invention, since the columnar high-frequency ferrite magnetic core is inserted and arranged inside the cylindrical low-frequency ferrite magnetic core, the insulating low-frequency ferrite magnetic core is provided. The insulating high-frequency ferrite core is interposed between the pair of windings that are separately wound on one side and the other side of the magnetic core. It serves as a partition member to insulate the pair of winding wires, and it is not necessary to provide a core case with a partition member to insulate the pair of winding wires. The pair of windings can be insulated.

[Brief description of drawings]

1A to 1C are perspective views showing an assembling procedure of an electromagnetic device for a noise filter according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing frequency characteristics of magnetic permeability of Ni—Zn ferrite material and Mn—Zn ferrite material.

FIG. 3 is a perspective view showing a structure of a composite magnetic core in a conventional noise filter electromagnetic device.

FIG. 4 is a perspective view of a core case and its peripheral portion showing an insulating configuration of a pair of windings in a common mode noise filter.

[Explanation of symbols]

 1 Ferrite core for low frequency 2,3 Vertical hole 4 Ferrite core for high frequency 5 Composite core 6,7 Winding

Claims (1)

[Scope of utility model registration request] 1. A columnar high-frequency ferrite core having a cylindrical low-frequency ferrite core core and a pair of vertical holes penetrating through the low-frequency ferrite core core, and being inserted and arranged inside the cylinder of the low-frequency ferrite core core with a gap left between them. A composite magnetic core composed of a magnetic core, and a pair that is separately wound on one side and the other side of the low frequency ferrite magnetic core and is inserted into a pair of vertical holes of the high frequency ferrite magnetic core. An electromagnetic device for a noise filter, comprising: