JP4656528B2 - Inductance element - Google Patents

Description

  The present invention relates to an inductance element used as a noise filter mainly in an AC line (AC line) or the like.

  In order to eliminate the adverse effect of the coil line-to-line capacitance on noise suppression when the inductance element is used in a high frequency region, the magnetic core is grounded and the coil is directly wound around the grounded magnetic core. A technique for forming a film has been proposed (see, for example, Patent Document 1 and Patent Document 2).

  On the other hand, the dielectric strength and the adjacent conductor are sequentially formed on the magnetic core on which the ground conductor is formed, and the coated conductor is wound on the magnetic core in which the withstand voltage of the coated conductor is a problem. In addition, there has been proposed a device in which the magnetic core and the coated conductor are separated, thereby improving the reliability (see Patent Document 3).

JP 9-102426 A JP 2004-31866 A JP 2004-235709 A

  In any of the techniques disclosed in Patent Documents 1 to 3 described above, some components must be grounded, and therefore a ground terminal must be provided.

  Accordingly, an object of the present invention is to provide an inductance element having a new structure capable of obtaining the same effect as the techniques described in Patent Documents 1 to 3 without providing a ground terminal.

  The present invention is an inductance element comprising a magnetic core and a winding having at least a part of a multi-core wire having a plurality of core wires as means for solving the above-mentioned problems, and is included in the multi-core wire An inductance element is provided in which one core wire is used as an inductor and the other core wire is in an electrically floating state.

  Of the core wires included in the winding, a core wire that is not used as an inductor may be fixed to, for example, an insulator, but does not need to be electrically connected to an external connection portion (for example, a ground pad on a substrate). .

  According to the present invention, since there is no need to provide a ground terminal in particular, the number of terminals can be reduced as compared with the techniques described in Patent Documents 1 to 3.

  The capacitance of the capacitor added to the inductance element can be adjusted by the number of turns of the linear conductor, and can flexibly cope with various situations.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The inductance element in the embodiment described below is for a common mode and includes two coated conductors. However, the present invention is not limited to this, and one coated conductor is used. The present invention can also be applied to a normal mode inductance element using only the book.

  As shown in FIGS. 1 and 2, the inductance element 14 a according to the embodiment of the present invention includes a toroidal magnetic core 15, a ring-shaped insulating case 16 that covers the outer peripheral surface of the magnetic core 15, and a single core. And the windings (coils) made up of the coaxial wires 17a and 18a.

  As shown in FIG. 3, the coaxial wires 17a and 18a are composed of a center conductor 21, an inner insulator 22, an outer conductor 23, and an outer insulator 24. In this embodiment, the center conductor 21 and the coated conductor 17, 18 conductors are connected at the connecting portion 19. That is, as shown in FIG. 1 and FIG. 2, the winding is performed after winding the covered conductors 17 and 18 halfway around an assembly in which the magnetic core 15 is incorporated into the insulating case 16. The coaxial conductors 17a and 18a connected to the coated conductors 17 and 18 are wound. That is, the conductors of the covered conductors 17 and 18 and the central conductor 21 of the coaxial wires 17a and 18a function as an inductor. Here, the outer conductor 23 of the coaxial lines 17a and 18a may be fixed to, for example, a terminal block (not shown). However, since it is not necessary to be electrically grounded, it is not necessary to provide a ground terminal. . That is, the outer conductor 23 of the coaxial lines 17a and 18a is used in an electrically floating state.

  Instead of the center conductor 21, the outer conductor 23 may be connected to the conductors of the covered conductors 17 and 18. In that case, the center conductor 21 is used in an electrically floating state.

  Further, in the example shown in FIGS. 1 and 2, the coated conductors 17 and 18 are wound halfway, and then the coaxial wires 17a and 18a connected to the coated conductors 17 and 18 are wound to form a winding. However, when it is desired to increase the number of windings, for example, as shown in FIGS. 4 and 5, the coated conductors 17, 18 are wound to form the first layer of the windings, and then the coated conductors 17, The coaxial wires 17a and 18a connected to the connecting portion 18 and the connecting portion 19 may be further wound around the coated conducting wires 17 and 18 to form a multi-layered winding.

  In the above-described embodiment, the location and area where the conductor 23a overlaps the coated conductors 17 and 18 are the number of turns (number of turns), the thickness and the length of the coated conductors 17 and 18, the size of the magnetic core 15, It can be appropriately changed depending on the material characteristics and the like.

  In the above-described embodiment, the example in which the coated conductors 17 and 18 and the coaxial wires 17a and 18a are connected to form the winding has been described. However, what is connected to the coated conductors 17 and 18 includes a plurality of core wires. It may be a multi-core wire having, and is not limited to a coaxial wire. For example, as the multi-core wire applicable to the present invention, parallel lines 17b, 18b and 17c, 18c as shown in FIGS. 6 and 7 and twist lines 17d, 18d and 17e as shown in FIGS. , 18e.

  As shown in FIG. 6, the parallel lines 17b and 18b are formed by insulating two conductors 21b1 and 21b2 arranged in parallel with each other with an internal insulator 22b and then covering with an external insulator 24b. One of the two conductors 21b1 and 21b2 is connected to the conductor of the covered conductors 17 and 18. The parallel lines may be formed by forming the inner insulator 22b and the outer insulator 24b as a single insulator, and a conductor electrically insulated from the conductors 21b1 and 21b2 is connected to the inner insulator 22b. It may be further interposed between the external insulators 24b. Similarly, as shown in FIG. 7, the parallel lines 17c and 18c are formed by insulating two parallel conductors 21c1 and 21c2 from each other, and then covering them with an external insulator 24c. One of the two conductors 21c1 and 21c2 is connected to the conductor of the covered conductors 17 and 18. These parallel lines may also be formed by forming the inner insulators 22c1 and 22c2 and the outer insulator 24c as one insulator, and the conductors 21c1 and 21c2 are electrically insulated from each other. It may be further interposed between the insulators 22c1 and 22c2 and the external insulator 24c.

  As shown in FIG. 8, the twist wires 17d and 18d are formed by twisting conductors 21d1 and 21d2 that are covered with the internal insulators 22d1 and 22d2 and insulated from each other, and are further covered with the external insulator 24d. One of the conductors 21d1 and 21d2 is connected to the conductor of the covered conductors 17 and 18. The twisted wire may be one in which a conductor electrically insulated from the conductors 21d1 and 21d2 is further interposed between the inner insulators 22d1, 22d2 and the outer insulator 24d. Similarly, as shown in FIG. 9, the twist wires 17e and 18e are formed by twisting conductors 21e1 and 21e2 covered with internal insulators 22e1 and 22e2 and insulated from each other.

  The present invention can be applied to, for example, a noise power filter or a switching power supply device including a noise filter.

It is a front view which shows the inductance element by embodiment of this invention. 2 is an enlarged cross-sectional view of a portion of the inductance element shown in FIG. 1 cut along a plane parallel to the paper surface of FIG. It is a perspective view which shows the coaxial line used for the inductance element shown by FIG. It is a front view which shows the modification of the inductance element shown by FIG. FIG. 5 is an enlarged cross-sectional view of a part of the inductance element shown in FIG. 4 cut along a plane parallel to the paper surface of FIG. 4. It is a perspective view which shows an example of the parallel line applicable to this invention. It is a perspective view which shows another example of the parallel line applicable to this invention. It is a perspective view which shows an example of the twist line | wire applicable to this invention. It is a perspective view which shows another example of the twist line | wire applicable to this invention.

Explanation of symbols

14a, 14a 'Inductance element 15 Magnetic core 16 Insulating case 17, 18 Coated conductor 17a, 18a Coaxial wire 19 Connection portion 21 Center conductor 22 Inner insulator 23 Outer conductor 24 This portion insulator 17b, 18b, 17c, 18c Parallel wire 17d, 18d, 17e, 17e Twisted wire

Claims (7)

An inductance element including a magnetic core and a winding having at least a part of a multi-core wire having a plurality of core wires, wherein one core wire included in the multi-core wire is used as an inductor and the other core wire is electrically In a floating state,
The winding further includes a single core wire connected in series to the one core wire of the double core wire, and the one core wire and the single core wire are used as an inductor,
The winding is formed by winding the single core wire halfway around the magnetic core and then winding the multicore wire connected to the single core wire.
Inductance element. The inductance element according to claim 1 , wherein one end of the one core wire and one end of the single core wire are used as lead terminals of the inductor, and the other end of the one core wire is connected to the other end of the single core wire. The inductance element according to claim 1 , wherein the multicore wire is a coaxial wire having a center conductor and an outer conductor, and the one core wire is either the center conductor or the outer conductor. The double wire is parallel lines formed by arranging in parallel the two conductors that are insulated from each other, the one of the core wire, said at one of two conductors, claim 1 or claim 2 The inductance element described. The double wire is a twisted wire made by twisting the two conductors that are insulated from each other, the one of the core wire, the said is one of two conductors, according to claim 1 or claim 2, wherein Inductance element. A filter circuit comprising the inductance element according to any one of claims 1 to 5 . A switching power supply device comprising the filter circuit according to claim 6 .

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