KR102009780B1 - Multilayered powder core - Google Patents

Abstract

Laminated powder cores are provided. Laminated powder core according to an embodiment of the present invention is a laminated powder core including at least two or more laminated cores press-molded with a magnetic powder material, the first laminated core having a round portion having a predetermined curvature at the corner of one surface; And a second laminated core having a rounded portion having a predetermined curvature at an edge of one surface thereof. Here, the other surface of the first laminated core and the second laminated core is not provided with a round portion, the other surface is laminated so as to face each other, the first laminated core and the second laminated core has the same thickness, the round portion is a round portion The total volume reduction rate of the first laminated core and the second laminated core by the has a curvature that satisfies 0.4 ~ 8%.

Description

Multilayered Powder Core

The present invention relates to a magnetic core, and more particularly, to a laminated powder core capable of simultaneously satisfying customer requirements and a large capacity as well as improvement of magnetic properties when implementing core stacking.

Generally, the powder core is manufactured by filling a mold with magnetic powder and then pressing to shape the powder. Such powder cores are wound around a central hole and an outer circumferential surface along the circumference for use as an inductor or noise filter.

At this time, the outer peripheral surface along the circumference of the powder core or the corner formed by the inner surface and both sides of the central hole is formed at almost right angles, so that the coating of the coil wound around the powder core is often scratched off by the edge of the powder core.

As such, when winding the coil on the powder core, as the coating of the coil is peeled off, the coil and the powder core are short-circuited, resulting in deterioration or poor performance of the product. Therefore, a company that manufactures a finished product by winding a coil on an externally manufactured powder core requires a certain curvature at the edge of the powder core.

In addition, the powder core is filled with a magnetic powder in a mold and pressure-molded, it is difficult to manufacture a product having a predetermined thickness or more in the structure of the mold, there is a limit in the implementation of uniform characteristics due to the density variation caused by pressure unevenness.

Therefore, there is an urgent need for the development of a powder core capable of high capacity while satisfying the request of the customer.

KR 10-1633190 B1 (2016.06.17 Enrollment)

The present invention has been made in view of the above points, and minimizes the volume loss when the core is laminated, thereby providing a laminated powder core capable of satisfying the requirements and capacity of the customer as well as improving the magnetic properties. There is this.

In order to solve the above problems, the present invention provides a laminated powder core comprising at least two laminated cores press-molded with a magnetic powder material. Here, the laminated powder core may include a first laminated core having a round part having a predetermined curvature at an edge of one surface thereof; And a second laminated core having a round portion having a predetermined curvature at an edge of one surface thereof, wherein the other surfaces of the first laminated core and the second laminated core are not provided with round portions, and the other surfaces are stacked to face each other. The first laminated core and the second laminated core have the same thickness, and the round portion has a curvature that satisfies a total volume reduction rate of 0.4 to 8% of the first laminated core and the second laminated core by the round portion. Has

According to a preferred embodiment of the present invention, the laminated powder core may further include at least one third laminated core disposed between the first laminated core and the second laminated core and not provided with round portions on both sides. have.

In addition, the magnetic powder material may include at least one of amorphous alloy powder, ferrite, and metal-based alloy powder.

In this case, the ferrite may be MnZn ferrite or NiZn ferrite.

In addition, the first laminated core and the second laminated core may include an epoxy coating layer.

In addition, the laminated core may be manufactured by a mold.

In addition, the round part may be formed by post-processing of the laminated core.

According to the present invention, by providing a round only in the outer periphery of the laminated core, by omitting the round in the laminated surface between the core, to minimize the volume loss of the entire core by the round, to satisfy the requirements of the customer for the winding of the coil At the same time, it is possible to suppress the deterioration of the characteristics due to volume loss, thereby improving the overall magnetic characteristics.

In addition, the present invention can achieve a large capacity by overcoming the limitation of the mold production and the limitation of the thickness increase of the powder core due to the pressure imbalance on the unit area by laminating a plurality of powder cores.

1 is a perspective view showing a laminated powder core according to an embodiment of the present invention;
2 is an exploded perspective view of FIG. 1;
3 is an enlarged cross-sectional view of a portion A of FIG.
4 is an enlarged cross-sectional view of the inner side of the laminated powder core central hole of FIG. 1;
5 is a perspective view showing a laminated powder core according to another embodiment of the present invention;
6 is an exploded perspective view of FIG. 5;
7 is an enlarged cross-sectional view of a portion B of FIG. 5;
8 is an enlarged cross-sectional view of the inner side of the laminated powder core central hole of FIG. 5, and
9 is a perspective view showing an example of a mold for manufacturing a laminated powder core according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. The drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification.

The laminated powder core 100 according to the embodiment of the present invention includes at least two or more laminated cores 110 and 120, as shown in FIGS. 1 and 2.

Here, in the multilayer powder core 100, coils are wound around the central holes 116 and 126 and the outer circumferential surface along the circumference, and thus may be used as a noise filter or an inductor. The laminated powder core 100 is press-molded with a magnetic powder, has an overall cylindrical shape, and has holes 116 and 126 at the center thereof.

At this time, the laminated powder core 100 is a powder core made of a constant thickness (t) because the thickness (t) that can be produced according to the pressure imbalance of the upper or lower portion of the mold when the magnetic powder is filled in the mold and pressure molding It is laminated | stacked in plurality. That is, the laminated powder core 100 is a laminate of at least two or more powder cores having a size (t) that can be produced according to the size of the total outer diameter (φ).

The first laminated core 110 is provided with a round portion having a predetermined curvature at the corner of the first surface 112. In one example, the first laminated core 110 may be disposed above the laminated powder core 100. Here, the first surface 112 is a surface on which the coil is wound and is the outermost surface of the laminated powder core 100, and may be an upper surface of the first laminated core 110.

In this case, the round part is provided at a corner where the inner surface of the central hole 116 and the first surface 112 are in contact, and at the corner where the outer circumferential surface and the first surface 112 of the first laminated core 110 are in contact with each other. That is, the first laminated core 110 may be provided with the round portion at the outer periphery of the first surface 112 and the inner periphery by the central hole 116.

In addition, the first laminated core 110 is not provided with a round portion having a predetermined curvature on the second surface 114 facing the first surface 112. That is, the second surface 114 of the first laminated core 110 may be formed as a flat surface (see FIG. 2). Here, the second surface 114 is a surface on which the coil is not wound and faces the second laminated core 120, and thus is a surface not exposed to the outside from the laminated powder core 100, and the laminated powder core ( 100).

The second laminated core 120 is provided with a round portion having a predetermined curvature at the corner of the first surface 122. In one example, the laminated powder core 100 may be disposed below the laminated powder core 100. Here, the first surface 122 is a surface on which the coil is wound, and is the outermost surface of the laminated powder core 100, and may be a lower surface of the second laminated core 120.

In this case, the round part is provided at a corner where the inner surface of the central hole 126 and the first surface 122 contact each other, and a corner where the outer circumferential surface of the second laminated core 120 and the first surface 122 contact each other. That is, the second laminated core 120 may be provided with the round portion at the outer periphery of the first surface 122 and the inner periphery by the central hole 126.

In addition, the second laminated core 120 is not provided with a round portion having a predetermined curvature on the second surface 124 opposite to the first surface 122. That is, the second surface 124 of the second laminated core 120 may be formed as a flat surface (see FIG. 2). Here, the second surface 124 is a surface on which the coil is not wound and faces the first laminated core 110, and thus is a surface not exposed to the outside from the laminated powder core 100, and the laminated powder core. It may be an upper surface of the (100).

As such, the first stacked cores 110 and the second stacked cores 120 may be stacked such that the second surfaces 114 and 124 having no rounded portions face each other.

As a result, a large capacity of the powder core can be achieved by solving a manufacturing problem in which the thickness of the powder core is limited due to the pressure imbalance on the unit area during the production of the powder core by the mold.

Here, the first laminated core 110 and the second laminated core 120 may have different thicknesses t, but may have the same thickness t for efficiency of the manufacturing process. That is, since the first laminated core 110 and the second laminated core 120 are manufactured to have the same thickness t, both of them may be manufactured by the same process, thereby improving efficiency of the manufacturing process.

In addition, a round portion having a predetermined curvature is provided on the first surface 112 of the first laminated core 110 and the first surface 122 of the second laminated core 120 corresponding to both surfaces of the stacked powder core 100. As a result, when the coil is wound around the laminated powder core 100, scratches do not occur in the coil, thereby preventing defects and improving product reliability.

At this time, since the overall volume of the laminated powder core 100 decreases as the curvature of the round part increases, the characteristics deteriorate, the round part should be provided with a curvature within a predetermined range.

To this end, in the laminated powder core 100 according to the embodiment of the present invention, a total volume reduction rate of the first laminated core 110 and the second laminated core 120 by the round part satisfies 0.4 to 8%. The round portion is provided to have a curvature. Here, the total volume reduction rate of the first laminated core 110 and the second laminated core 120 is the sum of the volume reduction rates by the round portion in each of the laminated cores 110 and 120, and the total volume of the laminated powder core 100. It means reduction rate.

At this time, when the volume reduction rate of the laminated powder core 100 is less than 0.4%, since the curvature of the round part is too small, a defect such as scratching of the coil by the round part occurs when winding the coil. That is, as the coating of the coil is peeled off, a short circuit occurs between the coil and the laminated powder core 100, resulting in a decrease in reliability of the product.

In addition, when the volume reduction rate of the laminated powder core 100 exceeds 8%, the volume reduction rate due to the round portion is too large, so that the magnetic properties are lowered. For example, when the laminated powder core 100 is used as an inductor, the inductance and the DC overlapping characteristics are lowered, thereby reducing the efficiency.

As such, by omitting and omitting rounds on the surfaces of the first laminated core 110 and the second laminated core 120 that do not face each other, the volume loss of the laminated powder core 100 by the round portion may be minimized. .

That is, since the compensation for the substantial volume loss of the laminated powder core 100 is generally made on both sides of the core in the same shape, the round provided on the first surface 112 of the first laminated core 110. It is achieved by the sum of the volume lost by the round and the round portion provided on the first surface 122 of the second laminated core 120.

In other words, the rounded portion provided on the first surface 112 of the first laminated core 110 is the same as the rounded portion provided on the second surface 114, and the first surface 122 of the second laminated core 120 is provided. ), The round part provided on the second surface 124 is the same as the round part provided on the second surface 124, and thus, the second surface 114 and the second laminated core 120 of the first laminated core 110 without the rounded part may be formed. Corresponding to the volume of the region a corresponding to the rounded portion omitted along the outer circumferential surface of the laminated powder core 100 at the joint surface A of the two surfaces 124 and the rounded portion omitted along the central holes 116 and 126. The sum of the volumes of the regions b is equal to the volume of the laminated powder core 100 lost by the round portion (see FIGS. 3 and 4).

Accordingly, as the round portions are omitted on the second surfaces 114 and 124 of the first laminated core 110 and the second laminated core 120 that face each other, the volume loss is compensated by the corresponding volume a + b, thereby stacking. Magnetic properties of the powder core 100 may be improved.

In addition, by the volume compensation as described above, the laminated powder core 100 may be provided with a rounded portion having a larger curvature compared to a constant magnetic property, it can more easily satisfy the requirements of the customer company.

As described above, the first laminated core 110 and the second laminated core 120 may be manufactured by pressing by a mold with a magnetic powder material.

Here, the magnetic powder material may include at least one of amorphous alloy powder, ferrite, and metal alloy powder. In this case, the ferrite may be MnZn ferrite or NiZn ferrite. However, the present invention is not limited thereto, and the stacked powder core 100 may be compression molded from any magnetic material in powder form.

For example, the first laminated core 110 and the second laminated core 120 insert the magnetic powder material into the receiving portion 16 of the mold 10, cover the lid 12, and then press molding by external pressure. (See FIG. 9).

At this time, the laminated core formed by the mold 10 may be formed on both surfaces thereof as a flat surface as shown in the third laminated core 230 shown in FIG. 9. Therefore, the first laminated core 110 and the second laminated core 120 may be provided with the round part by post-processing after being press-molded by the mold 10. That is, the round part may be formed by post-processing such as polishing after pressing the first laminated core 110 and the second laminated core 120 by a mold.

Thereby, since the round part can be formed with the various curvature also about the laminated powder core 100 which has the same thickness t and the outer diameter (phi), it can change a post process only and can respond quickly to the request of a customer company.

In addition, the first laminated core 110 and the second laminated core 120 may be provided with an epoxy coating layer. As a result, the surface of the first laminated core 110 and the second laminated core 120 is protected, and the surface resistance is increased to improve insulation with the coil, and the first laminated core 110 and the second laminated core ( Departure of the magnetic powder constituting the 120) can be suppressed.

In addition, the laminated powder core 100 may be provided with an adhesive layer between the first laminated core 110 and the second laminated core 120. However, the present invention is not limited thereto, and the first laminated core 110 and the second laminated core 120 may be fixed by winding coils, and thus may be laminated and fixed without using a separate adhesive layer.

Here, although the case of two laminated cores is illustrated and described, the laminated powder core according to an embodiment of the present invention may be composed of three or more laminated cores. For example, the stacked powder core 200 further includes at least one third stacked core 230 disposed between the first stacked core 110 and the second stacked core 120, as shown in FIG. 5. can do.

At this time, the third laminated core 230 is not provided with round portions on both sides. That is, both surfaces of the first surface 232 of the third stacked core 130 may be formed as a flat surface (see FIG. 6). Here, the first surface 232 and the second surface 234 of the third laminated core 230 are surfaces on which the coil is not wound. For example, the first surface 232 is a top surface of the third stacked core 230, and faces the first stacked core 110, and the second surface 234 is a bottom surface of the third stacked core 230. As an example, it may be a surface corresponding to the second laminated core 120.

Here, all of the first stacked core 110, the second stacked core 120, and the third stacked core 230 may have the same thickness t for the efficiency of the manufacturing process. That is, since the first laminated core 110, the second laminated core 120, and the third laminated core 230 are manufactured to have the same thickness t, all of them may be manufactured by the same process, thereby improving efficiency of the manufacturing process. Can be improved.

At this time, similar to the laminated powder core 100 of FIGS. 1 and 2, the compensation for the substantial volume loss of the laminated powder core 200 is a round provided on the first surface 112 of the first laminated core 110. Compensated by twice the sum of the volume lost by the round part provided in the wealth and the first surface 122 of the second laminated core 120.

That is, the first surface 232 and the second surface 234 of the third laminated core 230 and the second surface 114 or the second laminated core 120 of the first laminated core 110 which are not provided with the round portion. In the bonding surface B of each of the second surfaces 124 of the < RTI ID = 0.0 >), < / RTI > the volume of the regions a, a 'corresponding to the omitted rounded portions along the outer circumferential surface of the laminated powder core 200, The sum of the volumes of the regions b, b 'corresponding to the rounded portions thus omitted is twice the volume of the laminated powder core 200 lost by the rounded portions (see FIGS. 7 and 8). Here, the regions a and b between the first stacked core 110 and the third stacked core 230 and the regions a 'and b' between the second stacked core 120 and the third stacked core 230. ) Have the same volume, and each region has a volume lost by the round part.

Therefore, as the round portion is omitted for each of the opposing faces between the stacked cores between the first stacked core 110 and the second stacked core 120, the volume loss is compensated by a multiple of the corresponding volume a + b. It is possible to further improve the magnetic properties, and can be provided with a round portion having a larger curvature compared to the constant magnetic properties, it is possible to more easily meet the requirements of the customer.

At this time, the third laminated core 230 is manufactured by the mold 10 because the round portions are not provided on both sides, and post-processing for forming rounds may be omitted.

As a result, when the laminated powder core 200 includes at least three laminated cores, only the first laminated core 110 and the second laminated core 120 disposed at the outermost portion of the laminated powder core 200 have round portions. Since the post-processing to be provided, it is possible to improve the efficiency of the manufacturing process, and to quickly cope with the needs of customers due to the large capacity of the magnetic properties.

Although one embodiment of the present invention has been described above, the spirit of the present invention is not limited to the embodiments set forth herein, and those skilled in the art who understand the spirit of the present invention, within the scope of the same idea, the addition of components Other embodiments may be easily proposed by changing, deleting, adding, and the like, but this will also fall within the spirit of the present invention.

100,200: laminated powder core 110: first laminated core
112,122,232: first page 114,124,234: second page
116,126,236: central hole 120: second laminated core
230: third laminated core

Claims (7)

A laminated powder core comprising at least two laminated cores press-molded with a magnetic powder material,
A first laminated core having a round portion having a predetermined curvature at an outer periphery of one surface and an inner periphery of the central hole; And
And a second laminated core having a round portion having a predetermined curvature at an outer periphery of one surface and an inner periphery of the central hole.
The other surface of the first laminated core and the second laminated core is not provided with a round portion, and the other surfaces are laminated to face each other,
The first laminated core and the second laminated core has the same thickness,
The rounded part has a curvature such that the total volume reduction rate of the first laminated core and the second laminated core by the rounded part satisfies 0.4 to 8%. The method of claim 1,
Laminated powder core further comprises at least one third laminated core disposed between the first laminated core and the second laminated core, the round portion is not provided on both sides. The method of claim 1,
The magnetic powder material comprises at least one of amorphous alloy powder, ferrite, and metal-based alloy powder. The method of claim 3,
The ferrite is MnZn ferrite or NiZn ferrite laminated powder core. The method of claim 1,
The first laminated core and the second laminated core is a laminated powder core having an epoxy coating layer. The method of claim 1,
The laminated core is a laminated powder core produced by a mold. The method of claim 6,
The rounded powder core is formed by the post-processing of the laminated core.

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