JP2003249409A - Magnetic core for coil and inductance element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic core for a coil that can be further miniaturized with an equivalent magnetic characteristics as a conventional core. <P>SOLUTION: A magnetic core for a coil 1 comprises: a first magnetic core member 10 having the first plate-like part 12 and a columnar core part 11 that is erected at the center part of the first plate-like part 12; and a second magnetic core member 20 having a second plate-like part 21 having a through hole A allowing the columnar core part 11 to be fitted at the center part, and an outer tube part 22 that is hung from the periphery of the second plate-like part 21. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coil magnetic core, which is a component of an electric / electronic device such as an inductor or a transformer, and an inductance element using the same.

[0002]

2. Description of the Related Art Conventionally, as a magnetic core for a coil such as a transformer, E shown in a perspective view of FIG. 11A and a front view of FIG.
The -E type magnetic core 110 and the E-I type magnetic core 120 shown in the perspective view of FIG. 12 are generally used. There is an increasing demand for miniaturization and thinning of the coil magnetic core, which is a component of the electric / electronic device, and the drum magnetic core 130 shown in the perspective view of FIG. 13A and the front sectional view of FIG.
Is used. For example, for a mobile phone, the height of the magnetic core is 2 mm, the diameter of the collar 131 is 2 mm, and the thickness of the collar 131 is as thin as 0.5 mm.

14A shows a perspective view and FIG. 14B shows a front sectional view of a relatively large pot type magnetic core 140 used for a transformer for communication equipment. Japanese Unexamined Patent Publication No. 9-17192
In Japanese Patent Laid-Open No. 9-39, a technique for reducing the size of the choke coil 150 for a transformer is studied by using a double-sided tape as a lead wire and as a combination method of members constituting a magnetic core. Front sectional views of this magnetic core are shown in FIGS. 15 (a) and 15 (b), which simplifies the lead-out portion and the like.

[0004]

However, as shown in FIG.
In the EE type magnetic core 110 shown in FIG. 2, the respective ferrite magnetic core members 111 and 112 forming the magnetic core often have different dimensional accuracy after sintering, and the two magnetic core members 11
When the leg portions 111a and 112a are butted against each other when the magnetic core members 111 and 112 are small in size, the leg portions 111a and 112a are displaced from each other, or the leg portions 111a and 112a are opposed to each other. It becomes difficult to adjust the air gap to an appropriate value, and it is not possible to provide a coil core having stable magnetic characteristics. Also in the E-I type magnetic core 120 shown in FIG. 12, it is difficult to adjust the gap between the leg portion 121a of the E type magnetic core member 121 and the I type magnetic core member 122 to an appropriate value, and a coil magnetic core having stable magnetic characteristics is provided. Can not. Also, E-
In the inductance element in which the winding is wound around the E-type magnetic core 110 and the E-I-type magnetic core 120, there is a bare winding portion whose outer periphery is not covered by the magnetic core member, and the magnetic distribution cannot be utilized without waste. , Miniaturization is insufficient.

A drum type magnetic core 130 shown in FIG. 13 is formed by cutting a cylindrical body to wind a winding wire 133 around a core portion 132.
To form the collar 131 by reducing the size of the magnetic core.
As the thickness of the part decreases, the mechanical strength decreases,
There is a problem that chipping is likely to occur during processing and the yield is reduced. Further, the core portion 132 formed after cutting
In addition, when the winding 133 is wound, the tangle 131 may be chipped. The pot type magnetic core 140 shown in FIG.
In the above, the space between the columnar portions 141a and 142a arranged in the center of the upper and lower flat plate-shaped magnetic core members 141 and 142 is also
As with the E-E type magnetic core 110, it is difficult to adjust to an appropriate value, and it is not possible to provide a coil magnetic core having stable magnetic characteristics.

The technique disclosed in Japanese Patent Application Laid-Open No. 9-171929 shown in FIG. 15 has a structure in which an upper magnetic core member 151 is placed on a lower magnetic core member 152 and fixed with a double-sided tape 154. The area of the void portion is small, that is, the upper magnetic core member 15 of the lower magnetic core member 152.
Since the area of the surface facing 1 is small, the magnetic flux cannot be sufficiently passed, and the size of the coil core cannot be reduced.

The present invention has been made in order to solve such problems, and the magnetic core is composed of a plurality of magnetic core members,
Moreover, it is an object of the present invention to provide a magnetic core for a coil, which is improved by improving the magnetic characteristics of the magnetic core itself, and an inductance element using this magnetic core, by devising this combination method. Furthermore, it is an object of the present invention to provide a magnetic core for a coil in which leakage of magnetic flux due to a gap between magnetic core members when a plurality of magnetic core members are combined is suppressed and an amount of passing magnetic flux is increased, and an inductance element using this magnetic core. .

[0008]

DISCLOSURE OF THE INVENTION The inventors of the present invention have examined which part of the magnetic core the magnetic flux effectively passes through in the coil magnetic core. As a result, the inventor has conceived a magnetic core for a coil, which is composed of a plurality of magnetic core members, and by specifying the combination method, the winding is not exposed to the outside and a closed magnetic circuit can be formed. Since this coil magnetic core can utilize the magnetic characteristics of the magnetic core itself without waste, a miniaturized coil magnetic core excellent in magnetic characteristics and an inductance element using the same are provided.

The present invention has been made on the basis of such findings, and a first magnetic core member having a first plate-shaped portion and a columnar core portion standing upright in the central portion of the first plate-shaped portion. And a second hole having a through hole into which the columnar core is fitted, in a central portion thereof.
And a second magnetic core member having a plate-shaped portion and an outer cylindrical portion that hangs from the periphery of the second plate-shaped portion. In the coil magnetic core of the present invention, the columnar core portion of the first magnetic core member is fitted into the through hole of the second magnetic core member, and the tip of the outer cylindrical portion of the second magnetic core member is the first magnetic core member. Can be combined to contact the first plate-shaped portion of the. Then, since the winding wire is arranged in the space formed between the columnar core portion and the outer cylinder portion, the winding wire is not exposed to the outside. Moreover, the first plate-shaped portion, the columnar core portion, the second plate-shaped portion,
A closed magnetic circuit is formed in the order of the outer cylinder portion and the first plate-shaped portion (or vice versa). In the coil core of the present invention,
It is desirable to provide a magnetic member that covers a gap formed between the columnar core portion and the through hole. The coil magnetic core of the present invention can have magnetic characteristics superior to those of the conventional drum type magnetic core in the range where the gap is 50 μm or less. A sheet containing a soft magnetic material is preferably used as the magnetic member for covering the voids in order to reduce the size. The first magnetic core member and the second magnetic core member that compose the coil magnetic core of the present invention can both be made of a ferrite sintered body, and the first magnetic core member can be made of a ferrite sintered body. The second magnetic core member may be made of a soft magnetic material.

The present invention also provides an inductance element using the above coil core. This inductance element includes a first magnetic core member having a first plate-shaped portion and a columnar core portion standing upright in the center of the first plate-shaped portion, and a through hole into which the columnar core portion is fitted. A coil magnetic core including a second magnetic core member having a second plate-shaped portion having a central portion thereof and an outer tubular portion hanging from the periphery of the second plate-shaped portion; And a winding wire wound around the outer circumference. In the inductance element of the present invention, the winding is arranged in a space formed between the columnar core and the outer cylinder. Therefore, the winding wire is not exposed to the outside.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a coil magnetic core, an inductance element and a method of manufacturing the same according to the present invention will be described below with reference to the accompanying drawings. The present invention is not limited to this embodiment.

(First Embodiment) FIG. 1 shows a first convex shape.
The coil core 1 of the present invention in which the magnetic core member 10 (for example, made of a ferrite sintered body) and the second concave magnetic core member 20 (for example, made of a ferrite sintered body) are combined together is wound. 1 shows an inductance element according to an embodiment of the present invention in which a wire 30 is wound. FIG. 1A is a front sectional view of an inductance element according to the first embodiment, and FIG. 1B is an assembled perspective view thereof (coil is omitted).
Is. FIG. 2 is a front sectional view showing the assembling procedure.

The coil magnetic core 1 according to the first embodiment.
Has a columnar core portion 11 provided upright in the center, and the columnar core portion 1
1 having a convex shape having a first plate-shaped portion 12 that is integral with the first
Magnetic core member 10 and a concave second magnetic core member 20 having a second plate-shaped portion 21 having a through hole A in the center and an outer tubular portion 22 integrated with the second plate-shaped portion 21. Has been done. The outer cylinder portion 22 hangs from the periphery of the circular second plate-shaped portion 21. The tip of the columnar core portion 11 of the first magnetic core member 10 is fitted into the through hole A of the second magnetic core member 20 and functions as the coil magnetic core 1. A ring-shaped gap G is formed between the columnar core 11 and the through hole A. The coil magnetic core 1 according to the first embodiment is obtained by combining the first magnetic core member 10 and the second magnetic core member 20 as described above, so that the first plate portion 12, the columnar core portion 11, and the second core portion 11 A closed magnetic circuit is formed by the plate-shaped portion 21, the outer cylindrical portion 22, and the first plate-shaped portion 12. Since the closed magnetic circuit is formed, the magnetic characteristics of the coil core 1 are improved, as will be shown in Examples described later. In addition, a ring-shaped space is formed between the columnar core portion 11 of the first magnetic core member 10 and the outer cylindrical portion 22 of the second magnetic core member 20. A winding wire 30 is wound around the outer circumference of the columnar core 11 to form an inductance element.
Will be disposed in the space. Therefore,
The winding wire 30 is not exposed to the outside except for the lead-out portion. In the present invention, the columnar core portion 11 is expressed as standing and the outer cylinder portion 22 is expressed as hanging. This means that the first plate-like portion 12 is downward and the second plate-like portion is downward. It is based on the state that the upper portion 21 is arranged above.

In order to obtain the inductance element according to the first embodiment, first, the first magnetic core member 10 and the second magnetic core member 20 are manufactured. First magnetic core member 10
The second magnetic core member 20 is made of a ferrite sintered body as described above. Therefore, the first magnetic core member 10 and the second magnetic core member 20 are prepared by a known method whose main points are forming, sintering and processing of the raw material powder. The present invention does not specify the material of the ferrite sintered body to be used, and all known or later developed ferrite sintered bodies can be applied. If the first magnetic core member 10 and the second magnetic core member 20 are created,
As shown in FIG. 2, the columnar core portion 11 of the first magnetic core member 10
The winding wire 30 is wound around. Pre-wound winding 30
And the winding 30 can be arranged on the outer periphery of the columnar core 11. Then, the columnar core portion 11 of the first magnetic core member 10 is fitted into the through hole A of the second magnetic core member 20 to obtain the inductance element according to the first embodiment.

According to the coil magnetic core 1, the columnar core portion 11 and the second plate in the portion where the columnar core portion 11 of the first magnetic core member 10 is fitted in the through hole A of the second magnetic core member 20. The area of the surface facing the shape portion 21 can be sufficiently taken.
Therefore, sufficient magnetic flux can be passed between the columnar core portion 11 and the second plate-shaped portion 21. Therefore, by utilizing the magnetic characteristics of the coil magnetic core 1 itself without waste,
The magnetic characteristics (passing magnetic flux amount) can be improved as compared with the conventional drum type magnetic core 130 shown in FIG. This suggests that the coil magnetic core 1 according to the first embodiment can be made smaller than the drum type magnetic core 130 if the same characteristics are obtained. In the first embodiment,
Although the example of the disk-shaped first plate-shaped portion 12 and the second plate-shaped portion 21 is shown, the disk-shaped portion is not limited to the disk-shaped, and, for example, as shown in FIG. Can also be
Further, as the columnar core 11, an example of a columnar core in which the bundled winding wires 30 can be easily wound is shown, but the columnar core 11 is not limited to this, and a columnar core having another shape such as a prismatic core may be used. Good. In addition, in the first embodiment, both the first magnetic core member 10 and the second magnetic core member 20 are made of a ferrite sintered body, but the first magnetic core member 10 is made of a ferrite sintered body, and
The magnetic core member 20 can be made of a soft magnetic material.

(Second Embodiment) A second embodiment of the present invention will be described below. FIG. 3 is a front sectional view showing the coil magnetic core 1 according to the second embodiment. In order to further improve the performance of the coil magnetic core 1 according to the first embodiment, the coil magnetic core 1 according to the second embodiment suppresses leakage of magnetic flux and passes through the coil magnetic core 1 with the amount of magnetic flux. The magnetic member 40 that covers the gap G is arranged so as to increase. Further, FIG. 4 shows an assembling procedure of the coil magnetic core 1 according to the second embodiment. In FIGS. 3 and 4, the same parts as those in FIGS. 1 and 2 are designated by the same reference numerals, and the description thereof will be omitted.

As described in the first embodiment, the ring-shaped gap G is formed between the first magnetic core member 10 and the second magnetic core member 20. This gap G is formed by the first magnetic core member 1
0 and the manufacturing error of the second magnetic core member 20.
Then, since the magnetic flux leaks from the portion of the air gap G, the amount of magnetic flux passing through the coil magnetic core 1 decreases. The coil magnetic core 1 according to the first embodiment can be downsized because the performance is improved as compared with the commonly used drum type magnetic core 130, but the influence of the leakage magnetic flux due to the air gap G is suppressed. In the second embodiment, the gap G
The magnetic member 40 (a material having a soft magnetic characteristic similar to that of the material of the magnetic core, more specifically, a material having magnetic permeability) is arranged so as to cover the. Specifically, a sheet containing a soft magnetic material is attached to the second magnetic core member 20 using a double-sided tape or an adhesive so as to cover the gap G. By doing so, the gap G
Even if the magnetic flux leaks from the sheet, the magnetic flux passes through the sheet and returns to the first magnetic core member 10 or the second magnetic core member 20, so that a significant performance improvement (increase in the amount of passing magnetic flux) can be achieved. The size can be reduced accordingly. As a soft magnetic material,
Permalloy and ferrite can be used.

In the above example, the magnetic member 40 has a circular shape having an area similar to that of the second plate-like portion 21, but
If the ring-shaped void G can be covered, its size,
The shape does not matter. Further, in the second embodiment, the sheet of the soft magnetic material has been described as a preferable example, but a magnetic material other than the soft magnetic material may be used in order to suppress the leakage of the magnetic flux and increase the passing magnetic flux amount. .

[0019]

EXAMPLE The magnetic characteristics measured using the drum type magnetic core 130 shown in FIG. 13 will be described. Drum type magnetic core 130
Has a diameter of 2 mm, a height of 2 mm, a diameter of the core portion 132 around which the winding 133 is wound is 1 mm, and a thickness of the collar 131 is 0.5.
mm. The magnetic field analysis was performed by the finite element method.

When the thickness of the collar 131 is fixed to 0.5 mm and the height of the magnetic core is varied within the range of 3 to 1.5 mm,
Further, the distribution of the magnetic flux density in the radial direction was measured when the height was fixed to 1.5 mm and the thickness of the collar 131 was varied in the range of 0.5 to 0.1 mm. The area of the winding 133 at this time has a height of 0.5 mm and a width of 0.5 mm.
As a result, it was confirmed that the magnetic flux density reaches its maximum when there is no air gap between the winding 133 and the collar 131, and decreases when the thickness of the collar 131 is thin. That is,
It has been found that it is desirable that there be no gap above and below the winding 133 in order for the magnetic flux in the magnetic core to efficiently form a loop with respect to changes in the height of the magnetic core. A magnetic core can be downsized from the viewpoints of height and area, but since the height is a more important factor for surface mount components, the magnetic core height is 1.5
Other dimensions and shapes when mm was examined.

Regarding the conventional drum type magnetic core 130 shown in FIG. 13, the thickness of the collar 131 is 0.65 as shown in FIG.
mm, the height of the winding 133 portion is 0.2 mm, that is, the height of the magnetic core is 1.5 mm, and the width of the collar 131 is 0.5 to 0.5 mm.
Drum type magnetic core 13 when fluctuating within a range of 1.5 mm
The distribution of the magnetic flux density in the radial direction of 0 was measured. At this time, the width of the winding 133 was fixed at 0.5 mm. Results are shown in FIG. In FIG. 6, the horizontal axis indicates the position in the radial direction from the central axis of the drum type magnetic core 130, and the vertical axis indicates the magnetic flux density. It can be seen from FIG. 6 that the magnetic flux density increases as the width of the collar 131 increases. Further, in FIG. 7, the thickness of the collar 131 is 0.65 mm, the height of the winding 133 portion is 0.2 mm (the magnetic core height is 1.5 mm), and the collar 131 is
The width of the winding 133 is 0.5 mm, and the width of the winding 133 is 0.5 mm.
Also, the results of similarly measuring the magnetic flux density are shown for two types of 1.5 mm and 1.5 mm. As shown in FIG. 7, winding 1
It was confirmed that when the width of 33 is set to 1.5 mm and the winding 133 is wound up to the peripheral edge of the collar 131, the magnetic flux density is reduced. From this, it is understood that it is desirable to project the collar 131 to the outside of the outer circumference of the winding 133 in order to efficiently create a magnetic flux loop.

Next, a drum type magnetic core 130, which is considered to be the smallest in practical use for mobile phones, has a height of 1.5 mm, a diameter of 3 mm, and a collar 131 having a thickness of 0.65 m.
m, and a core having a diameter of 1 mm of the core portion 132 of the core was used for comparison with the coil core 1 (FIG. 1) of the present invention. The winding 133 at this time has a height of 0.2 mm and a width of 0.5 mm.
And The amount of magnetic flux passing through the cross section located at the center of the conventional drum type magnetic core 130 is 4.95 × 10 ⁻⁸ Wb.

In order to confirm the optimum shape and dimensions of the coil core 1 of the present invention, the following four types of coil cores were prepared and their magnetic characteristics were measured. The result is shown in FIG. In the figure, is the above-mentioned normal drum type magnetic core 130,
Is a magnetic core obtained by combining the drum-shaped magnetic core 130 with four upper and lower flanges 131, a core 132, and a portion outside the winding 133, and is a convex or concave shape shown in FIG. A coil magnetic core 1 according to the present invention in which two magnetic core members are combined shows the result when a magnetic core having the same shape as the coil magnetic core 1 according to the present invention is integrally formed. In addition,
Is integrally formed, so that there is no unavoidable gap G in the coil core 1 according to the present invention,
Can not be wound. That is, the measurement target was used to show the magnetic characteristics of an ideal magnetic core having no gap G. In addition, all the air gaps G in the magnetic cores of 10 μm
And

From FIG. 8, the conventional drum type magnetic core 130 is shown.
Compared with (), the coil magnetic core 1 () of the present invention in which two magnetic core members having a convex shape and a concave shape are combined can significantly improve the magnetic characteristics by closing the magnetic path even if there is a gap G. Recognize. In addition, the coil core 1 of the present invention is 2
Since the magnetic core member is formed of two convex and concave magnetic core members, unlike the conventional drum-type magnetic core 130, it is not necessary to perform difficult cutting work from a cylindrical body, and the yield at the time of manufacturing the magnetic core is not reduced. In addition, the amount of passing magnetic flux can be improved.

In the coil core 1 having the structure of the present invention,
FIG. 9 shows a change in the amount of magnetic flux passing through the cross section of the columnar core when the value of the gap G is changed. Here, the gap G refers to a gap in the fitting portion between the outer circumference of the tip of the columnar core portion 11 of the first magnetic core member 10 having a convex shape and the through hole A of the second magnetic core member 20 having a concave shape. As shown in FIG. 9, the coil magnetic core 1 of the present invention has far superior magnetic characteristics as compared with the conventional drum-shaped magnetic core 130 of 4.95 × 10 ⁻⁸ Wb. The amount of magnetic flux is tripled and the air gap G
Up to the range of 50 μm, the characteristics of the drum type magnetic core 130 having the gap G of 10 μm are exceeded.

Next, FIG. 10 shows the change in the amount of magnetic flux passing through the cross section of the columnar core portion when the height of the magnetic core is changed with the gap G of the coil core 1 of the present invention set to 10 μm. As shown in FIG. 10, the coil core 1 of the present invention has a conventional magnetic core height of 1.5 m.
The magnetic characteristics are far superior to those of the drum type magnetic core 130 of m, and the magnetic flux amount is tripled when the magnetic core height is 1.5 mm. Even if the magnetic core height is reduced to 0.5 mm, the characteristics of the drum type magnetic core 130 having a magnetic core height of 1.5 mm are surpassed. It can be seen that the coil magnetic core 1 of the present invention can be downsized to a size that is half or less the size of the conventional drum type magnetic core 130 if the magnetic characteristics are the same.

In the embodiment described above, the coil magnetic core 1 is formed by combining the convex first magnetic core member 10 having the columnar core portion 11 and the concave second magnetic core member 20 having the through hole A in the central portion. I explained. However, a sheet made of a soft magnetic material having a thickness larger than the through hole A and having a thickness of 10 μm is attached to the upper surface of the second plate-shaped portion 21 of the second magnetic core member 20 (attached with an adhesive layer having a thickness of 10 μm). ) Is arranged so as to cover the gap G formed by fitting the tip of the columnar core 11 and the through hole A, the soft magnetic sheet further suppresses leakage of magnetic flux from the gap G to the outside. An increase in the amount of passing magnetic flux occurs. If the soft magnetic sheet is the same material as the ferrite sintered body, 50% is obtained, and if the soft magnetic sheet has a relative magnetic permeability of 5,000, twice the amount of passing magnetic flux is obtained. Therefore, the coil magnetic core 1 of the present invention using the soft magnetic sheet is the coil magnetic core 1 of the present invention when the soft magnetic sheet shown in FIG. 8 is not used.
From the magnetic characteristics of (), the ideal magnetic core without air gap G ()
The magnetic characteristics of can be approached. Therefore, by using the soft magnetic sheet, it is possible to further improve the magnetic characteristics and reduce the size.

[0028]

As described above, according to the present invention,
With the same outer dimensions, the amount of passing magnetic flux in the vicinity of the center of the coil core can be increased up to about three times. Further, if the performance of the coil core is set to the same level, the volume of the core can be halved. This not only cuts the material cost in half, but can also reduce the height and area when the inductance element using this coil core is mounted on the board, which can also improve the mounting density of parts. It will be possible. Further, by devising a combination of magnetic core members constituting the coil magnetic core, from the viewpoint of manufacturing the magnetic core and electric / electronic devices, damage due to chipping or the like is reduced, and improvement in yield can be expected.

[Brief description of drawings]

FIG. 1 is a diagram showing a coil magnetic core and an inductance element according to a first embodiment of the present invention, in which (a) is a front sectional view and (b) is an assembled perspective view.

FIG. 2 is a front sectional view showing an assembling procedure of the inductance element according to the first embodiment of the invention.

FIG. 3 is a front sectional view showing a coil magnetic core and an inductance element according to a second embodiment of the present invention.

FIG. 4 is a front sectional view showing an assembling procedure of the inductance element according to the second embodiment of the invention.

FIG. 5 is a diagram showing the shape of a magnetic core when the width of the collar is changed in the drum type magnetic core.

FIG. 6 is a diagram showing a relationship between a width of a collar and a magnetic flux density in a drum type magnetic core.

FIG. 7 is a diagram showing the relationship between the width of the winding and the magnetic flux density when the width of the winding is changed in the drum type magnetic core.

FIG. 8 is a diagram showing a magnetic flux density when interpolation is performed in a coil magnetic core including a plurality of magnetic core members.

FIG. 9 is a diagram showing the relationship between the gap width and the amount of magnetic flux in the coil magnetic core of the present invention.

FIG. 10 is a diagram showing the relationship between the magnetic core height and the amount of magnetic flux in the coil magnetic core of the present invention.

FIG. 11 is a diagram showing a conventional EE type magnetic core, in which (a) is a perspective view and (b) is a front view.

FIG. 12 is a perspective view showing a conventional EI type magnetic core.

FIG. 13 is a view showing a conventional drum type magnetic core,
(A) is a perspective view, (b) is a front sectional view of an inductance element using this magnetic core.

14A and 14B are views showing a conventional pot type magnetic core, in which FIG. 14A is a perspective view and FIG. 14B is a front sectional view of an inductance element using this magnetic core.

FIG. 15 is a front sectional view of an inductance element using a coil magnetic core in which a conventional upper and lower magnetic core members are fixed with a double-sided tape.

FIG. 16 is an assembled perspective view showing another example of the coil magnetic core and the inductance element according to the first embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Magnetic core for coil, 10 ... 1st magnetic core member, 11 ... Columnar core part, 12 ... 1st plate-shaped part, 20 ... 2nd magnetic core member, 2
1 ... 2nd plate-shaped part, 22 ... Outer cylinder part, 30 ... Winding wire, 40
... magnetic member, A ... through hole, G ... void

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroyuki Tagami             4-21-806 Wakabadai, Asahi Ward, Yokohama City, Kanagawa Prefecture F-term (reference) 5E070 AA01 AB01 BA20

Claims (8)

[Claims] 1. A first magnetic core member having a first plate-shaped portion and a columnar core portion standing upright in a central portion of the first plate-shaped portion, and a through hole into which the columnar core portion is fitted. A magnetic core for a coil, comprising: a second magnetic core member having a second plate-shaped portion having a central portion thereof and an outer tubular portion hanging from the periphery of the second plate-shaped portion. 2. The magnetic core for a coil according to claim 1, further comprising a magnetic member that covers a space formed between the columnar core portion and the through hole. 3. The coil magnetic core according to claim 2, wherein the gap is 50 μm or less. 4. The coil core according to claim 2, wherein the magnetic member is formed of a sheet containing a soft magnetic material. 5. The coil magnetic core according to claim 1, wherein the first magnetic core member and the second magnetic core member are made of a ferrite sintered body. 6. The coil magnetic core according to claim 1, wherein the first magnetic core member is made of a ferrite sintered body, and the second magnetic core member is made of a soft magnetic material. 7. A first magnetic core member having a first plate-shaped portion and a columnar core portion standing upright in a central portion of the first plate-shaped portion, and a through hole into which the columnar core portion is fitted. A coil magnetic core including a second magnetic core member having a second plate-shaped portion having a central portion thereof and an outer tubular portion hanging from the periphery of the second plate-shaped portion; An inductance element, comprising: a winding wound around an outer circumference. 8. The inductance element according to claim 7, wherein the winding wire is arranged in a space formed between the columnar core portion and the outer cylinder portion.