JPH09120910A - Inductor and core thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a core of a thin, high-current inductor. SOLUTION: A core comprises a base magnetic member 2 having four or more protrusions 12, and a magnetic plate 3 opposed to the base magnetic member above the protrusions in such a manner that it can be magnetically coupled to the protrusions. The base magnetic member, adjacent two of the protrusions and the magnetic plate form an endless core that makes a shortest loop. Three or more such cores, into which at least one conductor is inserted, form an inductor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inductive element core made of a magnetic material and used as a magnetic flux path, and an inductive element such as a coil or a transformer using the core.

[0002]

2. Description of the Related Art For example, as choke coils, toroidal core type, EI core type and substrate type choke coils are known. The toroidal core type choke coil has an inductance value corresponding to the number of conductors wound around the winding frame of the toroidal core. EI
The core type choke coil is formed by winding a conductor around the middle frame or outer frame of an E-shaped core and then stacking the I-shaped core into a letter-like shape, and also has an inductance value according to the number of windings. doing. On the other hand, the board type choke coil has an EI type core and a printed board. A hole is formed in the printed circuit board, and the middle frame of the E-shaped core penetrates through the hole, so that the E-shaped core is disposed between both outer frames of the E-shaped core. Also, on the printed circuit board,
A spiral print pattern centered on the hole is formed, and this substrate type choke coil has an inductance value according to the number of spirals of the print pattern.

[0003]

However, this conventional choke coil has the following problems. That is, first, the conventional type choke coil cannot obtain the required inductance value unless the conductor is wound around the bobbin many times. Therefore, it is difficult to reduce the thickness of the inductive element due to the thickness of the wound conductor. In particular, when manufacturing a high power type inductive element, the diameter of the conductor has to be increased, which makes it very difficult to reduce the thickness. Further, it is difficult to reduce the thickness of the core itself. That is, the conductor must be wound around the core in the toroidal core type, and in the middle frame in the EI core type or the substrate type, a large number of times. Therefore, in order to secure the saturation magnetic flux density according to the number of turns and the current flowing through the conductor, the cross-sectional area of the core must be made very large. Particularly, in the case of a substrate type, it is necessary to form the print pattern in a spiral shape, and therefore, if a thick print pattern is formed, the substrate area becomes very large. In this case, it is possible to obtain a predetermined inductance value by stacking a plurality of printed circuit boards, but in such a case, it becomes difficult to make the EI core thin due to the thickness of the printed circuit board itself, and a plurality of printed circuit boards are required. The cost increases because it is necessary to connect the print patterns on the board in series.

Secondly, the above three types have a problem that it is difficult to manufacture a choke coil for a large current. That is, the saturation magnetic flux density of the core is proportional to the product of the current and the number of turns. Therefore, the saturation magnetic flux density of the core must be increased as the number of turns and the flowing current are increased. On the other hand, in the above three types, since the conductor is wound a plurality of times around the inner frame of the toroidal core or the EI core, if the cross-sectional area of the core per conductor is correspondingly increased, the EI core becomes very large. It becomes large. Therefore, in consideration of downsizing the EI core, it is necessary to use a core having a very high saturation magnetic flux density.
In reality, in order to manufacture a new core having a higher saturation magnetic flux density, it is necessary to wait for the appearance of a new material.

Further, in the substrate type, since the conductor has a spiral shape, the distance between the outer conductor and the EI core becomes large, resulting in a large amount of leakage magnetic flux.

The present invention has been made in view of the above problems, and provides an inductive element core capable of manufacturing a thin inductive element for a large current, and an inductive element using the same. The main purpose is to do.

[0007]

In order to achieve the above object, the core for an inductive element according to claim 1 sandwiches a columnar magnetic body with a base magnetic body in which at least four columnar magnetic bodies are provided upright. Is a core for an inductive element provided with a magnetic plate capable of being magnetically coupled to each of the columnar magnetic bodies, the base magnetic body, two columnar magnetic bodies adjacent to each other, And at least three endless cores that close the magnetic path in the shortest by the magnetic plate, and the inductive element can be formed by inserting at least one conductor into the plurality of endless cores. In addition, the endless core, when the magnetic path is closed by the magnetic body itself,
This is a concept including both cases where magnetic bodies are magnetically coupled to each other via a gap.

In this inductive element core, at least three endless cores whose magnetic paths are closed in the shortest direction are formed by the base magnetic body, the two columnar magnetic bodies adjacent to each other, and the magnetic body plate. In this case, when one conductor is inserted through the endless core, the conductor becomes an inductive element having a predetermined inductance based on the magnetic permeability and cross-sectional area of the endless core. Therefore, when the conductor is inserted through the plurality of endless cores, equivalently, an inductive element in which a plurality of the inductive elements are connected in series is formed. Therefore, when a large inductance value is required, a conductor may be inserted through many endless cores, and when a large current inductive element is required, a thick conductor may be used. . In this case, the conductor insertion hole of the endless core has only to allow one conductor to be inserted, and the endless core has a cross-sectional area corresponding to the current flowing through the one conductor. . Therefore, since the base magnetic body can be formed in a plane, the inductive element core and the inductive element using the core can be thinned.

According to a second aspect of the present invention, there is provided an inductive element core according to the first aspect, in which the base magnetic body is elongated and the columnar magnetic bodies are erected in one row. It is characterized by

In this inductive element core, since the columnar magnetic bodies are erected in one row, it is possible to manufacture a thin and narrow inductive element core and an inductive element using the same. .

The core for an inductive element according to claim 3 is the core for an inductive element according to claim 1, wherein the columnar magnetic body is
It is characterized in that the base magnetic body is erected vertically and horizontally in a plurality of rows.

In this inductive element core, since the columnar magnetic bodies are erected vertically and horizontally in a plurality of rows, a large number of endless cores are formed. Therefore, it is possible to easily manufacture an inductive element having a large inductance value, and it is possible to employ any one of a number of insertion methods that is easy to insert.

According to a fourth aspect of the present invention, there is provided an inductive element core according to any one of the first to third aspects, wherein the columnar magnetic body has a polygonal or circular cross section. It is characterized by being formed.

In this core for an inductive element, the cross section of the columnar magnetic body is formed in a polygonal shape or a circular shape such as a circular shape or an elliptical shape, so that when the conductor is inserted, scratches are less likely to occur, and as a result, The reliability of the inductive element manufactured by using this inductive element core is improved.

A core for an inductive element according to a fifth aspect is the core for an inductive element according to any one of the first to fourth aspects, in which a hole is formed in a portion of the base magnetic body other than the standing portion of the columnar magnetic body. Is provided.

In this inductive element core, when manufacturing an inductive element for a large current, heat is generated between the base magnetic body and the magnetic plate due to the current flowing through the conductor. This heat is generated. The heat is radiated to the outside from the hole provided in the base magnetic body. Therefore, the core is suitable as a core of a large-current inductive element. Moreover, the endless core can be three-dimensionally formed by inserting the conductor into the hole.

A core for an inductive element according to a sixth aspect is the core for an inductive element according to any one of the first to fifth aspects, in which a hole is formed in a portion other than a portion of the magnetic plate facing the columnar magnetic body. It is characterized in that a section is provided.

In this inductive element core, since holes are formed in the magnetic plate, heat can escape more easily, and as a result, the heat dissipation effect can be further improved.

A core for an inductive element according to claim 7 is the core for an inductive element according to any one of claims 1 to 6, wherein a gap is formed between the magnetic plate and at least one columnar magnetic body. Characterized by what is possible.

In this inductive element core, an endless core formed of a base magnetic body, a columnar magnetic body and a magnetic plate is magnetically coupled via a gap. Therefore, by inserting the conductor, a so-called unsaturated type inductive element is easily formed. Therefore, it can be used for so-called magnetic amplifiers.

An inductive element core according to an eighth aspect is the inductive element core according to any one of the first to seventh aspects, wherein the base magnetic body is a wall-shaped magnetic body for surrounding the columnar magnetic body. It is characterized by having.

In this inductive element core, the columnar magnetic material is shielded by the base magnetic material and the magnetic material plate. Therefore, by using this, an inductive element having no leakage magnetic flux can be formed.

An inductive element according to a ninth aspect comprises the inductive element core according to any one of the first to eighth aspects, and at least one conductor that passes through the plurality of endless cores. It is characterized by

With this inductive element, it is possible to provide an inductive element having a large inductance value and an inductive element for a large current, as described in the core for inductive elements according to the first aspect.

The inductive element according to claim 10 is the same as in claim 9.
The inductive element described above is provided with a plurality of conductors, and the inductive element is a transformer.

In this inductive element, the transformer is easily manufactured by inserting a plurality of conductors into the endless core. In addition, a transformer having an arbitrary winding ratio can be easily manufactured by appropriately changing the number of inserted conductors.

The inductive element according to claim 11 is the same as in claim 9.
Alternatively, in the inductive element described in Item 10, the conductor is formed in a sheet shape.

In this inductive element core, the inductive property is easily obtained by arranging the printed circuit board on which the conductor is printed into the gap between the columnar magnetic bodies before the magnetic plate and the base magnetic body are bonded. The device can be manufactured.
In this case, if a plurality of endless cores are formed in the inductive element core, it is not necessary to insert many conductors into one endless core, so that the conductors can be inserted in the shortest distance. Therefore, the leakage magnetic flux can be extremely reduced as compared with the conventional substrate type choke coil.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments to which an inductive element core according to the present invention and an inductive element using the same are applied will be described below with reference to the accompanying drawings.

FIG. 1 shows a choke coil (inductive element) 1 mounted on a printed circuit board. Choke coil 1
As shown in the figure, each has a base magnetic body 2 and a magnetic body plate 3 each formed of a magnetic body, and the base magnetic body 2 and the magnetic body plate 3 are bonded to each other with the printed circuit board 4 interposed therebetween. It In this case, the magnetic material is M
nZn-based ferrite, NiZn-based ferrite, NiZn
Ferrite materials such as Cu-based ferrites and NiFe-based ferrites, and oxide-based or metal-based materials such as permalloy and sendust are used, but not limited to them, and any substance that is magnetized when placed in a magnetic field is used. be able to.

The base magnetic body 2 is composed of nine rectangular parallelepiped core legs (columnar magnetic bodies) 12a, 12b, 12c, which are erected on the base 11 in vertical and horizontal directions of three rows (hereinafter, simply referred to as " Core foot 12 "). .. are formed at the same height, and when the magnetic plate 3 is adhered to the base magnetic body 2, the two core legs 12, 12 and the base 1 that are adjacent to each other are formed.
1 and the magnetic plate 3 form an endless unit core having the shortest magnetic path length. The hole of this unit core, that is,
The groove 14 formed by the core legs 12, 12, ...
A conductor 13 is provided. Although the unit core will be described in detail later, by inserting the conductor 13 into the hole of the unit core, a coil having a predetermined inductance value determined by the cross-sectional area of the unit core, the magnetic permeability of the magnetic body, and the like is formed. It is formed.

The core leg 12 has a predetermined cross-sectional area. Specifically, assuming that the cross-sectional areas of the core feet 12a arranged at the four corners of the base 11 are value 1, the cross-sectional area of the core feet 12b arranged around the base 11 other than the four corners is 1.5. The other cross-sectional area of the core foot 12c is configured to have the value 2. The cross-sectional shape of the core foot 12 is arbitrary and can be formed in various shapes such as a square, a rectangle, an ellipse, and a circle. In the present embodiment, the rectangular shape is adopted for the reason of easy molding. However, considering that the conductor 13 is damaged when the conductor 13 is inserted, the cross section is formed in a circular shape such as a circular shape or an elliptic shape as much as possible. It is preferable.

The magnetic material plate 3 is formed in a plate shape, and when the printed board 4 is sandwiched together with the base magnetic material 2, the magnetic material plate 3 comes into surface contact with the upper surfaces of the core legs 12, 12 ,. As a result, the magnetic plate 3 is magnetically coupled to the core legs 12 and 12 to form the aforementioned unit core. However, the present invention is not limited to this, and the magnetic plate 3 is provided with fitting holes for fitting the core legs 12, 12, ... Good.

The printed circuit board 4 is made of, but is not limited to, a glass epoxy type material, and each core leg 12,
A plurality of holes 21, 21 ... Are formed at positions facing each other so that 12 ... In addition, the printed circuit board 4 has an end portion 13 of the conductor 13.
Through holes 22a and 22b for penetrating a and 13b upward from the lower side of the printed circuit board 4 in the figure to enable soldering are provided, and both through holes 22a and 22b are not shown. Printed patterns 23a and 23b, the other ends of which are connected to the electric circuit, are respectively connected.

Next, the operating principle of the choke coil 1 will be described with reference to FIGS. Choke coil 1
Is, in principle, equivalent to a combination of twelve unit cores 31, 31, ... As shown in FIG. The unit core 31 is a magnetic plate 32 shown in FIGS.
And a base magnetic body 33 shown in FIGS. As described above, the unit core 31 forms a closed magnetic path, and all the cross-sections orthogonal to the magnetic path have the same area. The reason why the cross-sectional areas are made equal at this time is to eliminate waste of the magnetic material by making the magnetic flux densities in all the cross-sections equal. When the number of conductors 13 inserted into the unit core 31 is not the same, it is desirable to make the cross-sectional area proportional to the number of inserted conductors 13.

In the unit core 31, each core leg 34 in each unit core 31 is represented by a point 36, 36 ..., And in each unit core 31, each hole 35 formed by the base magnetic body 33 and the magnetic plate 32 is formed. 37 and 37.
By expressing with, it is modeled as shown in FIG. In this case, inserting the conductor 13 through the hole 35 of the unit core 31 is equivalent to the conductor 13 crossing the side 37. Then, by traversing once, one unit coil is formed. Therefore, since the choke coil 1 in FIG. 1 traverses the side 37 12 times, it is equivalent to a series connection of 12 unit coils 38, 38 ... As shown in FIG. In this way, the conductor 13
, By appropriately changing the number of times the conductors cross the sides 37, 37 ,.
It is possible to form the choke coil 1 having various inductance values by changing the number of insertions.
Further, by appropriately changing the order in which the conductor 13 crosses the sides 37, 37, ..., That is, by changing the order in which the conductor 13 is inserted through the hole 35 in the unit core 31,
A method that facilitates insertion of the conductor 13 can be adopted. Further, the plurality of conductors 13 can be inserted into the unit core 31 and the plurality of conductors 13 can be connected in parallel. In this case, a choke coil for large current can be formed.

If the unit core 31 alone is used, the opening 39 is necessarily formed as shown in FIG. Therefore, an opening may be formed in the base 11 in FIG. In this case, when the choke coil 1 is used as a large current choke coil, even if a large current flows through the conductor 13 and heat is generated, the heat can be radiated to the outside from the opening 39. In addition, the conductor 13 is provided in the opening 39.
, The conductor 13 is inserted into the closed magnetic circuit formed by the four unit cores 31, 31 ..., And in this case, the unit coil is equivalently formed.

Further, as shown in FIG. 6, a choke coil 43 in which a plurality of core legs 41, 41, ... Are arranged in a line on a long base magnetic body 42 may be constructed. It should be noted that the illustration of the magnetic plate is omitted in FIG. In this case, if the cross-sectional area of the outer core legs 41, 41 is set to 1, the cross-sectional area of the inner core legs 41, 41 ,. Can be uniform. This is the inner core foot 41, 41
Because it can be considered that the two core feet are united. When the choke coil 43 is further simplified and modeled, as shown in FIG.
This is equivalent to connecting the unit coils in the same number as the number of times of crossing 7 in series.

Further, as shown in FIG.
A transformer can also be configured by using 3, 44, 45, 46, and 47. In this case, the conductor 43
, By inserting the conductors 44 to 47 into the holes 48 once, respectively, so that the primary side coil 51 with 8 turns as shown in FIG. A transformer 53 in which each of the four secondary coils 52, 52 ... Makes one turn.

Similarly, as shown in FIG. 10, a transformer 65 can be constructed by adding other conductors 61, 62, 63, 64 to the choke coil 1 shown in FIG. 1, and a perspective view of the appearance in this case is shown. 11 shows. In this transformer 65, four openings (holes) 67, 67 ... Are formed in the base magnetic body 66.
Are formed, and each of the openings 67, 67, ... Functions as a heat dissipation port for escaping heat accumulated in the base magnetic body 66. The equivalent circuit is shown in FIG.
Is a 24-turn primary winding 71 corresponding to the conductor 13,
It is composed of three turns of secondary windings 72 to 75 corresponding to the conductors 61 to 64, respectively. In this case, the number of turns of the secondary winding can be set according to the number of times the unit core is inserted, and the number of turns of the secondary winding can be set to an arbitrary number by using conductors as many as necessary. Can be a number.

As described above, according to the choke coil 1 according to the present embodiment, the core foot 12 may be formed at a height that allows the conductor 13 to be inserted therethrough, so that the choke coil 1 can be made thin. it can. Further, by increasing the number of core legs 12 to increase the number of unit cores 31 and increasing the number of unit cores 31 to be inserted by the conductor 13,
It is possible to easily form a choke coil or a transformer having a large inductance value. Furthermore, in such a case, since the diameter of the conductor used can be set to an arbitrary thickness, the choke coil and transformer for large current can be easily configured.

A gap may be provided between the core leg 12 and the magnetic plate 3 in the above-mentioned choke coil 1 and the like. In such a case, a so-called unsaturated choke coil can be formed and can be used in a so-called magnetic amplifier. Furthermore, by providing the gap, the inductance value of the conductor 13 (unit coil) inserted in the unit core 31 can be finely adjusted.

Further, the number of the core legs 12 can be arbitrarily determined, and the arrangement thereof can be appropriately changed. Further, the conductor 13 does not need to be inserted into all of the unit cores 31 formed in the base magnetic body 2, and may be inserted in a number that allows a desired inductance value to be inserted, and conversely,
Of course, the conductor 13 may be inserted into one unit core 31 a plurality of times.

Next, another embodiment of the inductive element will be described with reference to FIGS.

The transformer 81 shown in FIGS. 13 and 15 includes a base magnetic body 82, a magnetic plate 83, and printed boards 84 and 85.
And an insulating sheet 86. The base magnetic body 82 includes four core legs (columnar magnetic bodies) 87, 8
7 ... is erected and the wall portion (wall-shaped magnetic body) 88,
.. are erected so as to surround the core legs 87, 87. Further, four notches 89, 89 ... Are formed near the four corners of the base magnetic body 82, and each notch 89, 89.
Connection terminals 93, 9 described later when the
It functions as an outlet of 3,94,94, respectively. on the other hand,
A printed pattern 91 for the primary coil and a printed pattern 92 for the secondary coil are formed on the printed boards 84 and 85, respectively. The print pattern 91 is coated with a resist so as to be insulated from other components, and has connection terminals 93, 93 formed at its ends. The printed pattern 92 is also coated with a resist so as to be insulated from other parts, and at the end thereof, the connection terminal 9 is formed.
4, 94 are formed. The connection terminals 93, 93 and 94, 94 are connected to the printed circuit boards 84 and 8 respectively.
Print patterns are formed on both front and back surfaces of No. 5, and the print patterns on both surfaces are electrically connected by through holes 93a, 93a and 94a, 94a. Further, the resist is removed from the portions of the connection terminals 93, 93, 94, 94, so that it can be easily soldered to other parts or a printed pattern on another printed board. Accordingly, for example, when the transformer 81 is arranged on another printed board, the printed patterns and terminals formed on the printed board are easily and reliably connected to the connection terminals 93, 93, 94, 94. Can be done. The insulating sheet 86 completes the insulation between the printed circuit board 84 and the printed circuit board 85.
The transformer 81 includes the printed circuit board 8 in the base magnetic body 82.
4, the insulating sheet 86 and the printed circuit board 85 are arranged in that order, and then the magnetic plate 83 is attached to the base magnetic plate 82 and the magnetic plate 8 as shown in FIG.
All parts are built in 3.

Next, an outline of the operating principle of the transformer 81 will be described. The print patterns 91 and 92 are shown in FIG.
As shown in (a) and (b) respectively, core feet 87, 8
.. and the wall portions 88, 88 .. are inserted between a plurality of unit cores, respectively, to form a plurality of unit coils. Form primary and secondary windings. In this transformer 81, when the print pattern 91 is inserted through the notches 89, 89, ..., Unit coils each having one turn are formed. On the other hand, the notch 8
Even if the print pattern 92 is inserted through 9, the unit coil is not formed at that portion. This is because the print patterns 92 reciprocate within the unit core, and the magnetic fluxes cancel each other out. Further, at the portion indicated by the arrow 96, the print pattern 91 is inserted between the core legs 87, 87 that are diagonally opposed to each other, but the print pattern 91 reciprocates in the unit core, and the unit coil Is not formed. As shown in FIG. 14, the transformer 81 is equivalently configured with a 10-turn primary coil 97 and a 4-turn secondary coil 98.

As described above, according to the transformer 81, since the wall portions 88, 88 ... Enclose the core legs 87, 87 .. And the print patterns 91, 92, the magnetism does not leak to the outside. A perfect magnetic shield effect can be obtained. Further, by disposing the printed circuit boards 84 and 85 in the base magnetic body 82, inductive elements such as coils and transformers can be easily manufactured. In this case, a choke coil and a transformer suitable for mass production can be provided. However, the present invention is not limited to this, and a sheet-shaped conductor obtained by punching a copper foil or the like into a predetermined shape may be disposed in the base magnetic body 82 to easily form the inductive element. In addition, in the case of being configured as a transformer, by applying a resist to the print patterns 91 and 92 formed on the two printed boards 84 and 85, or disposing an insulating sheet 86, the primary and The secondary circuits can be easily insulated.

In the transformer 81, it goes without saying that the secondary coil may be omitted and the coil may simply be constructed. By forming print patterns on the front and back of one printed circuit board, respectively, the primary coil and the secondary coil are formed. It may be configured to form a secondary coil. Further, the printed circuit boards 84 and 85 can be configured by flexible printed circuit boards, or can be configured by general paper or glass epoxy substrates.

[0049]

As described above, the core for inductive element and the inductive element according to the present invention have the following effects. Since the cross-sectional area of the core per conductor can be made extremely small, the core for inductive element can be thinned. At the same time, the inductive element can be easily thinned. Since many endless cores can be arranged in a plane, by inserting conductors into multiple endless cores, it is possible to easily form an inductive element with a large inductance value, and by inserting thick conductors. A high power inductive element can be easily formed. Not only can inductive element cores of various shapes be manufactured, but also various types of winding inductive element cores can be manufactured. Furthermore, a large number of independent coils can be formed on one inductive element core, and a transformer having many secondary coils can be formed. When used as a high power core, the areas of the base surface and the magnetic material plate surface can be increased, so that it is possible to provide a core for an inductive element having an excellent heat dissipation effect. By stacking a plurality of inductive elements formed using this inductive element core, it becomes possible to form an inductive element having an extremely large inductance value. The conductor can be easily arranged on the columnar magnetic tube without requiring a special winding machine or the like. Compared with a conventional inductive element in which a large number of conductors are wound on the same plane, the conductor length can be substantially shortened, and as a result, an inductive element with less copper loss can be provided. .

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a choke coil according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining the operating principle of the choke coil according to the embodiment of the present invention.

3A is a plan view of a magnetic plate, FIG. 3B is a side view of the magnetic plate, FIG. 3C is a plan view of a base magnetic part, and FIG. It is a side view of a body part.

FIG. 4 is a diagram modeling the choke coil shown in FIG.

5 is an equivalent circuit diagram of the choke coil shown in FIG.

FIG. 6 is a plan view of a choke coil having core legs arranged in a row with a magnetic plate removed.

FIG. 7 is a diagram modeling the choke coil in FIG.

FIG. 8 is an external perspective view of the transformer according to the present embodiment.

9 is an equivalent circuit diagram of the transformer shown in FIG.

FIG. 10 is a plan view of the transformer according to the present embodiment with a magnetic plate removed.

FIG. 11 is an external perspective view of the transformer in FIG.

12 is an equivalent circuit diagram of the transformer in FIG.

FIG. 13 is an exploded perspective view of a transformer according to another embodiment.

FIG. 14 is a circuit diagram of the transformer in FIG.

15 is an external perspective view of the transformer in FIG.

16 (a) is a diagram showing a primary winding of the transformer in FIG. 13, and FIG. 16 (b) is a diagram showing a secondary winding of the transformer in FIG.

[Explanation of symbols]

 1 Choke Coil 2 Base Magnetic Material 3 Magnetic Material Plate 4 Printed Circuit Board 12 Core Foot 13 Conductor 39 Opening 43 Choke Coil 65 Transformer 66 Base Magnetic Material 67 Opening 81 Transformer 82 Base Magnetic Material 83 Magnetic Material Plate 84 Printed Circuit Board 85 Printed Circuit Board 91 Print Pattern 92 Print Pattern

Claims (11)

[Claims] 1. A base magnetic body in which at least four columnar magnetic bodies are erected, and a base magnetic body sandwiching the columnar magnetic body so as to be opposed to the base magnetic body and magnetically coupled to each of the columnar magnetic bodies. A core for an inductive element including a magnetic plate capable of being formed, wherein at least the base magnetic body, the two columnar magnetic bodies adjacent to each other, and the endless core that closes a magnetic path in the shortest manner by the magnetic plate. A core for an inductive element, comprising three, and capable of forming an inductive element by inserting at least one conductor into the plurality of endless cores. 2. The core for an inductive element according to claim 1, wherein the base magnetic body is formed in an elongated shape, and the columnar magnetic bodies are provided upright in one row. 3. The core for an inductive element according to claim 1, wherein the columnar magnetic body is provided upright on the base magnetic body in a plurality of vertical and horizontal rows. 4. The core for an inductive element according to claim 1, wherein the columnar magnetic body is formed to have a polygonal shape or a circular cross section. 5. The core for an inductive element according to claim 1, wherein a hole is provided in a portion of the base magnetic body other than a standing portion of the columnar magnetic body. . 6. The inductive element according to claim 1, wherein a hole is provided in a portion of the magnetic plate other than the portion facing the columnar magnetic body. core. 7. The core for an inductive element according to claim 1, wherein a gap can be formed between the magnetic plate and at least one of the columnar magnetic bodies. 8. The core for an inductive element according to claim 1, wherein the base magnetic body includes a wall-shaped magnetic body surrounding the columnar magnetic body. 9. An inductive element, comprising: the inductive element core according to claim 1; and at least one conductor that passes through the plurality of endless cores. . 10. The inductive element according to claim 9, comprising a plurality of the conductors, wherein the inductive element is a transformer. 11. The inductive element according to claim 9, wherein the conductor is formed in a sheet shape.