JP6784513B2 - Winding iron core, manufacturing method of winding iron core - Google Patents

Description

An embodiment of the present invention relates to a wound iron core formed by laminating thin plate-shaped magnetic materials and a method for manufacturing the wound iron core.

Conventionally, a wound iron core formed by laminating thin plate-shaped magnetic materials is known. As disclosed in Patent Document 1, for example, such a wound iron core has a structure that can be divided into a plurality of pieces by cutting a material obtained by laminating magnetic materials in an annular shape. This divided structure is widely adopted because it is easy to insert a coil and the assembly process is easy because the divided iron cores can be easily formed into an annular shape by joining them. There is.

Japanese Unexamined Patent Publication No. 2015-8238

The entire wound iron core is solidified by impregnating the layers of the magnetic material with resin. In this case, the stress generated by mechanical compression or bending in the process of solidifying the resin remains as it is as residual stress when the resin is solidified. As a result, the wound iron core in the state where the resin is solidified has a problem that the iron loss and the exciting current increase as compared with the state in which the magnetic material is simply wound.
Therefore, a method for manufacturing a wound iron core and a wound iron core capable of suppressing an iron loss and an increase in an exciting current is provided.

The wound iron core of the embodiment is formed by laminating thin plate-shaped magnetic materials to form an annular shape, and the impregnated region solidified by impregnating the layers of the magnetic material with resin and the layers of the magnetic material are not impregnated with resin. It is characterized by providing a non-impregnated region.

The method for manufacturing the wound core of the embodiment includes a winding step of forming a wound core in which a thin plate-shaped magnetic material is wound, and a setting step of setting an impregnated region in which a resin is impregnated between layers of the magnetic material and solidified. It is characterized by including an impregnation step of impregnating the impregnated region with a resin and a cutting step of cutting the wound iron core at a predetermined cutting position in the impregnated region in a state where the resin is solidified.

The figure which shows typically the winding iron core by embodiment The figure which shows the cross section of the impregnation region schematically. The figure which shows the cross section of the non-impregnated region schematically. The figure which shows typically the manufacturing process of a winding iron core

Hereinafter, embodiments will be described with reference to FIGS. 1 to 4.
As shown in FIG. 1, the wound core 10 of the present embodiment includes two divided cores 11 which are joined to each other to form a substantially annular shape. The wound iron core 10 is formed by, for example, winding an amorphous material (amorphous material) or a magnetic material 14 formed of a nanocrystal material in a thin plate shape in an annular shape. Further, the wound iron core 10 has a structure that can be divided into each other at the joint surface of the divided iron core 11 (corresponding to the cutting position P described later). Therefore, when the wound iron core 10 is used, for example, in a transformer or the like, it can be easily inserted into a coil (not shown) by dividing it into divided iron cores 11 at the cutting position P.

Each of the divided cores 11 will be described in detail in FIG. 4, which will be described later, but the wound core 11A (see FIG. 4) formed by winding the magnetic material 14 in an annular shape is cut at a predetermined cutting position P. As a result, it is formed in a U shape. Then, by joining the divided cores 11 to each other at the cutting position P, a substantially rectangular annular wound core 10 having chamfered corners is formed.

In this wound iron core 10, the impregnated region S solidified by impregnating the layers of the magnetic material 14 in a state of being laminated by winding with the resin 12 (see FIG. 2) and the layers of the magnetic material 14 are not impregnated with the resin 12. An impregnated area is provided.
In the case of the present embodiment, the impregnation region S is provided only within a predetermined range of the annular wound iron core 10 sandwiching the portion to be the cutting position P. In other words, the region of the annular wound iron core 10 excluding the impregnated region S is the non-impregnated region.

More specifically, as shown in FIG. 2, for example, in the cross section of the impregnated region S in the line II-II of FIG. 1, the resin 12 is impregnated between the layers of the magnetic material 14, and the magnetic material 14 and the resin 12 Are alternately laminated. Therefore, as the resin 12 is solidified, the shape and position of the laminated magnetic material 14 are firmly fixed in the impregnated region S. Although the state in which the resin 12 does not exist on the laminated end surface 11a is illustrated in FIG. 2 for simplification of the description, the laminated end surface 11a, that is, the laminated end surface 11a is used as a rust preventive measure on the front surface and the back surface of the wound iron core 10. It may be covered with resin 12.

On the other hand, as shown in FIG. 3, for example, in the cross section of the non-impregnated region in lines III-III of FIG. 1, the resin 12 does not exist between the layers of the magnetic material 14. That is, in the non-impregnated region, the resin is not impregnated between the layers of the magnetic material 14. Therefore, in the non-impregnated region, the magnetic material 14 is allowed to fluctuate to some extent in its shape and position. Further, in the non-impregnated region, the laminated end surface 11a of the magnetic material 14, that is, the cut surface when the magnetic material 14 is manufactured is coated with the coating material 13 to prevent rust.

The coating material 13 is a material that is more flexible than the resin 12, has a higher viscosity than the resin 12, in other words, has low fluidity and can form a certain film thickness, and is an interlayer of the magnetic material 14. It is made of a material that is difficult to impregnate. Examples of the coating material 13 include a resin material and the like, and for example, an adhesive or a rust preventive paint may be used.

Next, the operation of the above configuration will be described.
First, recent technological trends will be described. For example, in transformers for distribution, there is a strong demand for energy saving and high efficiency, such as the establishment of standards and regulations that require high efficiency worldwide, as represented by the application of the so-called Top Runner Program in Japan. There is. Above all, efforts are required to reduce no-load loss (so-called iron loss), which is a loss that occurs in the iron core, and each manufacturer is focusing on improving iron loss by improving materials and structures.

When an iron-based amorphous material (amorphous material) is used as the magnetic material for forming the iron core, the magnetic material is generally obtained by applying a molten raw material to a rotating roll to quench it. Manufactured. For this reason, the magnetic material has a thin plate shape or ribbon shape of about several tens of microns at the material stage.
Then, in order to use such a thin magnetic material for a transformer or the like, it is widely practiced to wind and laminate the magnetic material to form an iron core solidified with a resin or the like. When a nanocrystal material formed in a thin plate shape is used as the magnetic material, or when a general silicon steel formed in a thin plate shape is used, an iron core having the same structure is often formed.

By the way, in the magnetic material formed of an amorphous material or a nanocrystal material, stress such as mechanical compression or bending is generated when the resin is impregnated between the layers or when the impregnated resin is solidified. Then, the deformation of the magnetic material is regulated by the solidification of the resin, and the generated stress remains as a residual stress as it is. As a result, when the iron core is formed, the iron loss and the exciting current increase as compared with the state in which the magnetic material is simply wound.

Hereinafter, the wound iron core 10 of the present embodiment, which can suppress an increase in magnetic current, will be described together with a manufacturing method thereof in response to the current situation where such energy saving and high efficiency are strongly required.
As shown in FIG. 4, the wound iron core 10 has a winding step of winding a thin plate-shaped magnetic material 14 to form a wound iron core 11A, and an impregnated region in which the resin 12 is impregnated between the layers of the magnetic material 14 and solidified. A setting step of setting S, an impregnation step of impregnating the impregnated region S with the resin 12, a coating step of coating the non-impregnated region with the coating material 13, and an impregnation step of impregnating the impregnated region S with the resin 12 and solidifying the impregnated region S. , The resin 12 is manufactured by a manufacturing method including a cutting step of cutting the wound iron core 11A at a predetermined cutting position P in the impregnated region S in a solidified state.

In the winding step, the thin plate-shaped magnetic material 14 is wound by using a jig (not shown) to form a wound iron core 11A in which the magnetic material 14 is laminated in an annular shape. The wound iron core 11A becomes a plurality of divided iron cores 11 by being cut at the cutting position P.

In the setting step, the wound iron core 10 is firmly fastened at a predetermined position of the wound iron core 11A while applying pressure in the thickness direction, that is, the laminating direction of the magnetic material 14 by the fastening jig 20. As a result, the layers of the magnetic material 14 come into close contact with each other at the portion where the fastening jig 20 is fastened. Therefore, when the impregnated region S is impregnated with the resin 12 in the next impregnation step, it is suppressed that the resin 12 is impregnated outside the impregnated region S beyond the fastening jig 20. That is, in the setting step, the impregnation region S, which is the range in which the resin 12 is impregnated, is set.

Further, in the setting step, in the present embodiment, a range including the portion to be the cutting position P indicated by the broken line, more strictly speaking, a predetermined range sandwiching the portion to be the cutting position P is set as the impregnation region S. To. In this embodiment, this predetermined range is set to at least the width required for cutting the wound iron core 11A. Further, in the present embodiment, the predetermined range is a range in which the resin 12 does not reach the R-shaped corner of the wound iron core 11A, in other words, the stress due to the winding tightening when winding the magnetic material 14 It is set in the range excluding the corners that are likely to occur.

In the impregnation step, the impregnated region S is impregnated with the resin 12 and solidified. In the present embodiment, although not shown, the wound core 11A is installed sideways, that is, the laminated end surface 11a is installed along the direction of gravity, and the liquid resin 12 is poured into the impregnated region S from above the wound core 11A. The resin 12 is impregnated between the layers of the magnetic material 14. In FIG. 4, the resin 12 impregnated between the layers of the magnetic material 14 is schematically shown by hatching.

In this case, the position where the fastening jig 20 is fastened is the boundary between the impregnated region S and the non-impregnated region. That is, between the layers of the magnetic material 14, the magnetic materials 14 are brought into close contact with each other by the fastening jig 20, so that the leakage of the resin 12 to the outside of the impregnated region S is suppressed, while the laminated end face 11a has the laminated end surface 11a. The fastening jig 20 functions as an embankment to prevent the coating material 13 from invading the impregnated region S side.
In the coating step, the laminated end face 11a of the non-impregnated region excluding the impregnated region S is coated with the coating material 13.

In the cutting step, the wound iron core 11A is cut at a predetermined cutting position P in the impregnation region S in a state where the resin 12 is solidified. As a result, two divided iron cores 11 are formed. Then, by joining the divided cores 11 to each other at the cutting position P, the annular wound core 10 is formed. Although not shown, a polishing step of horizontally polishing the cut surface is performed after the cutting step.

By such a manufacturing method, a wound iron core 10 is manufactured which is formed in a ring shape as a whole, an impregnated region S is provided in a part thereof, and the resin 12 is impregnated and solidified. The range in which the resin 12 is solidified is smaller than that in the case of such a wound iron core 10 in which the entire resin 12 is solidified or the entire core 10 is fixed by an adhesive or the like.

According to the wound iron core 10 described above, the following effects can be obtained.
The wound iron core 10 is formed by laminating thin plate-shaped magnetic materials 14 to form an annular shape. The impregnated region S solidified by impregnating the layers of the magnetic material 14 with the resin 12 and the resin between the layers of the magnetic material 14. A non-impregnated region not impregnated with 12 is provided. That is, the wound iron core 10 is provided with an impregnated region S in a part of the ring, and the impregnated region S is solidified by impregnating the resin 12 between the layers of the magnetic material 14, while the resin is solidified in the portion excluding the impregnated region S. 12 is not impregnated.

Therefore, the range in which stress is generated due to the impregnation and solidification of the resin 12 of the wound iron core 10 is smaller than that of the conventional one in which the entire core is impregnated with the resin 12 and solidified. Further, since the wound iron core 10 is not impregnated with the resin 12 in the portion excluding the impregnated region S, the magnetic material 14 is allowed to be deformed to some extent in the portion excluding the impregnated region S.

As a result, the wound iron core 10 is generated because the stress itself generated when the resin 12 is impregnated and solidified can be reduced, and the magnetic material 14 can be deformed to some extent in the portion not impregnated with the resin 12. It is possible to prevent the stress from remaining as a residual stress. Therefore, it is possible to suppress iron loss and an increase in exciting current.

Further, the wound iron core 10 has a structure in which it is cut at a predetermined cutting position P and can be divided, and the cutting position P is provided in the impregnation region S. When cutting the wound iron core 11A (see FIG. 4), a grindstone is used as a cutting jig because the magnetic material 14 is very thin and, for example, an amorphous material generally has a high hardness. There are many. In that case, for example, if only the surface of the wound iron core 10, for example, the laminated end surface 11a is solidified with the resin 12, the magnetic material 14 inside may be significantly deformed.

Therefore, by setting the cutting position P as the impregnated region S, the resin 12 is impregnated between the layers of the magnetic material 14 and solidified in the impregnated region S, so that the magnetic material 14 is deformed when cut with a grindstone. Can be suppressed to some extent. Therefore, it is possible to suppress the generation of stress and prevent the magnetic material 14 from falling apart after cutting, and it is possible to improve workability during manufacturing and subsequent assembly.

The wound iron core 10 is provided with the impregnation region S only within a predetermined range sandwiching the portion to be the cutting position P. At this time, the predetermined range is set to a range including at least the width required for cutting as described above. As a result, the portion where stress is generated when the resin 12 is impregnated and solidified can be suppressed to the minimum necessary, and iron loss and an increase in exciting current can be suppressed.

As the magnetic material 14, the wound iron core 10 uses an amorphous material or a nanocrystal material formed in a thin plate shape. Amorphous materials are suitable for high-frequency transformers and the like because iron loss at high frequencies is smaller than that of silicon steel plates that are widely used as iron core materials. Further, since the nanocrystal material is also a material specialized for high frequency, it is suitable for a high frequency transformer and the like. Therefore, by adopting an amorphous material or a nanocrystal material, the characteristics of the transformer, particularly the characteristics at high frequencies, can be improved.

In the wound iron core 10, the laminated end surface 11a of the magnetic material 14 in the non-impregnated region is coated with a coating material 13 that is more flexible than the resin 12. As a result, the end surface of the magnetic material 14, that is, the cut surface when the magnetic material 14 is formed into a thin plate shape is coated, and the occurrence of rust can be prevented. Further, the wound iron core 10 can be maintained in an annular shape, that is, the divided iron core 11 can be maintained in a substantially U shape.

Further, a winding step of winding the thin plate-shaped magnetic material 14, a setting step of setting an impregnated region S for impregnating and solidifying the resin 12 between the layers of the magnetic material 14, and an impregnation for impregnating the impregnated region S with the resin. The wound iron core 10 manufactured by a manufacturing method including a step and a cutting step of cutting the wound iron core 11A at a predetermined cutting position P in the impregnated region S in a solidified state of the resin 12 has the above-mentioned iron loss. It is possible to obtain effects such as suppressing an increase in the exciting current.

(Other embodiments)
The present invention is not limited to the above-described embodiments, and the configurations and structures shown in the respective embodiments can be arbitrarily modified or combined without departing from the gist thereof.
FIG. 2 schematically shows the number of magnetic materials 14 and the resin 12 and their thicknesses in order to illustrate the state in which the magnetic materials 14 and the resins 12 are alternately laminated, and does not necessarily show the exact shape. Not a translation. Similarly, FIG. 3 schematically shows the number and thickness of the magnetic material 14 and the coating material 13 in order to illustrate the state in which the coating material 13 is provided on the laminated end surface 11a, and does not necessarily have a strict shape. It does not show.

The method of impregnating the impregnated region S with the resin 12 is not limited to the method exemplified in the embodiment, and another method may be used as long as the resin 12 can be impregnated between the layers of the magnetic material 14.

In the embodiment, it is illustrated that the resin 12 is solidified in the impregnation step, but it is not always necessary to wait until the resin 12 is solidified in the impregnation step, and the coating step is performed by utilizing the time for the resin 12 to solidify. May be good.

The impregnation region S is set in the impregnation step in order to prevent the resin 12 from being impregnated in an unnecessarily wide range. Therefore, it is not always necessary to impregnate the resin 12 to the limit of the fastening jig 20, and conversely, even if the resin 12 is impregnated to a extent slightly exceeding the fastening jig 20, it does not pose a big problem. That is, the impregnated region S may be at least set in a range that can be correctly cut in the cutting step.

In the embodiment, it is exemplified that the coating step is performed after the resin 12 is solidified, but the coating step may be performed by utilizing the time for the resin 12 to solidify as described above, or may be performed before the impregnation step. It may be performed after the cutting step. However, since the split iron core 11 may expand after the cutting step, it is preferable to perform the split iron core 11 before the cutting step in order to facilitate handling.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

In the drawing, 10 is a wound core, 11 is a split core, 11A is a wound core, 11a is a laminated end face, 12 is a resin, 13 is a coating material, 14 is a magnetic material, 20 is a fastening jig, P is a cutting position, and S. Indicates the impregnated region.

Claims (3)

It is a wound iron core formed by laminating thin plate-shaped magnetic materials into an annular shape.
An impregnated region solidified by impregnating resin between the layers of the magnetic material and a non-impregnated region not impregnated with resin are provided between the layers of the magnetic material.
The wound core is cut at a predetermined cutting position and can be divided into a plurality of U-shaped divided cores.
The cutting position is provided in the impregnated region and
The laminated end face of the magnetic material in the non-impregnated region is coated with a coating material that is more flexible than the resin .
The impregnated region is provided only within a predetermined range of the annular wound core with the portion to be the cutting position interposed therebetween . The wound iron core according to claim 1, wherein the magnetic material is formed of an amorphous material or a nanocrystal material in a thin plate shape. The winding process of forming a wound core by winding a thin plate-shaped magnetic material, and
A setting step of setting an impregnated region in which a resin is impregnated between layers of the magnetic material and solidified, and a non-impregnated region not impregnated with the resin.
An impregnation step of impregnating the impregnated region provided only within a predetermined range sandwiching a portion to be a cutting position in the annular wound iron core with a resin.
A cutting step of cutting the wound core at a predetermined cutting position in the impregnated region and dividing the wound core into a U-shaped divided core in a state where the resin is solidified.
A coating step of coating the laminated end face of the magnetic material in the non-impregnated region with a coating material more flexible than the resin.
A method for manufacturing a wound iron core, which comprises.

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