JPH0138898Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an electromagnetic induction equipment core, particularly an electromagnetic induction equipment core that reduces iron loss that occurs in a picture frame core.

Conventionally, as this type of iron core, for example, there has been one shown in FIG. 1 of the accompanying drawings. That is, in the figure, numerals 1 to 3 are leg irons, 1 and 2 are outer leg irons, 3 is a central leg iron, and numerals 4 to 7 are leg irons.
are yokes, 4 and 5 are upper yokes, and 6 and 7 are lower yokes. These outer and central leg irons 1, 2,
3, upper and lower yoke irons 4 to 7 are made of electric iron plates, and the rolling direction and the magnetization direction are made to coincide with each other.
It is cut into a frame shape and laminated so that the magnetic flux can easily pass through the connecting portions with the lower yoke 4 to 7.

In FIG. 1, solid lines indicate the core pieces in the upper layer, and dotted lines indicate the core pieces in the next layer, which are different from the core pieces in the upper layer.

Generally, unidirectional silicon steel sheets are used for these electrical steel sheets, and the properties of these unidirectional silicon steel sheets have made remarkable progress. Highly oriented silicon steel sheets with enhanced orientation in one direction have been developed and are now in use.

This highly oriented silicon steel sheet has improved orientation in the rolling direction (L direction) compared to conventional unidirectional silicon steel sheets, so the magnetic properties when magnetized in the rolling direction are greatly improved. However, on the other hand, when magnetized in the direction perpendicular to the rolling direction (direction C), the magnetic properties deteriorate. In other words, the so-called L/C
This means that the ratio becomes larger. When such a highly oriented silicon steel sheet is used for an electromagnetic induction device core such as a transformer core, the iron loss of the entire electromagnetic induction device core is lower than when a conventional unidirectional silicon steel sheet is used. However, on the other hand, it has the disadvantage that the building factor of iron loss becomes extremely poor. One reason for this is that there is a problem in the parts where the magnetic flux passes from the outer and central leg irons 1, 2, and 3 to the upper and lower yoke irons 4, 5, 6, and 7, that is, the connection parts. That is, in this part, the magnetic flux needs to pass through the space of the connection part, so the concentration of magnetic flux occurs.The other reason is that the magnetic flux is concentrated in this part because it needs to pass through the space of the connection part. ,5,
When the magnetic flux passes to 6 and 7, the direction of magnetization and the rolling direction of the electric iron plate deviate because the magnetic flux needs to bend. In addition, in this portion, as shown in FIG. 2, so-called rotating magnetic flux is generated whose direction of magnetic flux changes with time. however,
In the figure, numerals 1a and 4a indicate the alternating magnetic flux generated in the outer leg iron 1 and the upper yoke 4, and numeral 8 shown at the connection part indicates the alternating magnetic flux 9a, 9b, 9c.
indicates a rotating magnetic flux whose phase gradually deviates greatly from the alternating magnetic flux 8. As a result, in the case of an electric iron plate having a large L/C ratio of magnetization characteristics, such as a highly oriented silicon steel plate, the building factor of iron loss becomes worse. Figure 3 shows the results of calculating the building factors for each part using the finite element method when using a unidirectional silicon steel plate and a highly oriented silicon steel plate for the core of the electromagnetic induction equipment. This is an example. In the figure, the values in the upper row are the building factors for highly oriented silicon steel sheets, and
The values in the lower row show the building factors for unidirectional silicon steel sheets. In the case of an electromagnetic induction equipment core using a highly oriented silicon steel plate, the building factor at the connection between the outer leg irons 1 and 2 and the upper and lower yoke irons 4, 5, 6, and 7 is extremely high. The disadvantage was that the low iron loss characteristics of the highly oriented silicon steel sheet could not be utilized, resulting in an uneconomical core for electromagnetic induction equipment.

The purpose of the present invention is to provide an electromagnetic induction equipment core that reduces iron loss by eliminating the drawbacks of the conventional electromagnetic induction equipment core using highly oriented silicon steel sheets as described above. In order to achieve this purpose, a linear minute strain is applied to the mutually connecting parts of the outer leg irons and yoke of each laminated layer in a direction perpendicular to the magnetic flux passing through that part. It is characterized by the presence of

Hereinafter, the present invention will be explained based on the accompanying drawings showing one embodiment thereof.

FIG. 4 shows leg irons according to the present invention, namely outer leg irons 11, 12, central leg irons 13,
and yokes, that is, upper yokes 14, 15, and
An electromagnetic induction equipment core composed of lower yokes 16 and 17, leg irons 11 to 13 and yokes 14 to 17.
The outer leg iron core pieces 11a and 12 are the iron core pieces of
As shown in FIGS. 5A, B, C, and D, which respectively show the central leg iron core piece 13a, the upper and lower joint iron core pieces 14a and 17a, and the same 15a and 16a, the outer leg iron 11a , 12a and yoke 14a, 17
a, 15a, and 16a only in a direction perpendicular to the magnetic flux passing therethrough, for example, from the viewpoint of processing convenience, a direction that collectively forms 45 degrees with respect to the rolling direction X. A linear minute strain 18 is applied to the core, and an electromagnetic induction device core is constructed by laminating the core pieces 11a to 17a formed in this way.

Applying appropriate linear microstrain to such unidirectional silicon steel sheets is based on the fact that the 180° magnetic domain is subdivided, which is said to reduce iron loss. This is particularly noticeable in highly oriented silicon steel sheets, and has been confirmed and reported through experiments. When this linear microstrain is applied perpendicularly to the rolling direction of a unidirectional silicon steel sheet, the iron loss in the rolling direction (L direction) increases; The iron loss in the direction perpendicular to the direction (C direction) is respectively reduced.
If this linear microstrain is applied in a direction that is 45° to the rolling direction of a unidirectional silicon steel sheet, especially a highly oriented silicon steel sheet, the rolling direction (L direction),
In addition, the iron loss in the direction perpendicular to the rolling direction (direction C) is moderately reduced even if it does not show the maximum reduction rate. This will be explained in more detail as follows.

What is shown in FIG. 6 shows the magnetic flux distribution at the connection part between the outer leg iron 11 and the yoke 14, for example. According to this, since the magnetic flux 19 bends at the connection part, the magnetic flux parallel to the rolling direction , and a magnetic flux component perpendicular to the rolling direction. This means that if iron loss is to be reduced, iron loss characteristics in the direction perpendicular to the rolling direction (direction C) must also be low.

FIG. 7 shows the iron loss value when exciting from the C direction and the L direction at the same magnetic flux density when a small strain is applied at an arbitrary angle with respect to the rolling direction. According to this, the iron loss value in the L direction + C direction when the angle of microstrain with respect to the rolling direction is 0°, 45°, 90° is (a ₂ + b ₂ ) < (a ₁ + b ₁ ) (a ₂ + b ₂ ) < (a ₃ + b ₃ ), and the iron loss value is the lowest at 45°. 6th
As shown in the figure, since the magnetic flux bends at the connection between the outer leg iron 11 and the yoke 14, the magnetic flux densities in the L direction and the C direction are considered to be approximately the same, so the connection part between the outer leg iron 11 and the yoke 14 is considered to be approximately equal in magnetic flux density. This shows that the iron loss value can be reduced by applying a small strain to. Also, leg iron 1
The connecting parts between 1 to 13 and yokes 14 to 17 are:
This is the part where the magnetic flux crosses in a curved manner, and the magnetic flux has a component in the direction perpendicular to the rolling direction (direction C). Also, as shown in FIG. 2, rotating magnetic flux is also generated. Therefore, as in the present invention, each iron core piece 11a to 11a is made of an electric iron plate, in particular a highly oriented silicon steel plate, which is not given linear microstrain 18 in a direction at 45 degrees with respect to the rolling direction. If 17a is stacked, leg iron 1
Since the connecting portions between the yokes 1 and 12 and the yokes 14 to 17 are made non-directional, the occurrence of iron loss in these portions is reduced, and the building factor is therefore improved.

Note that the part where the center leg iron 13 and the yokes 14 to 17 connect is not subjected to minute strain in the direction that is 45 degrees to the rolling direction. This is because when the center leg iron is not excited, there is a magnetic flux that runs parallel to the rolling direction in the yoke, and adding a small strain may actually increase iron loss.

FIG. 8 shows the calculation results of the building factors of the electromagnetic induction equipment core of the present invention constructed as described above in the case where the core piece is formed from a highly oriented silicon steel plate. According to this, it can be seen that the building factor of iron loss in the connecting portions between the leg irons 11 and 12 and the yokes 14 to 17 has been improved by about 7%.

Note that this linear minute strain 18 is caused by the leg irons 11 to 13.
Also, it is not preferable that it be applied over the entire surface of the electric iron plate forming the yokes 14 to 17. That is, the method of imparting the linear micro-strain 18 to the electric iron plate is by marking (scratching) the electric iron plate. These markings damage the insulating film that maintains insulation between laminated electrical steel plates, but electromagnetic induction devices such as transformers generally have windings wrapped around the iron core. An electrical impulse is applied to the winding to verify insulation (not shown). If there is a flaw in the insulating surface film on the surface of the electrical steel plate, the electromagnetic induction effect between the winding wire and the iron core due to electrical impulses will cause dielectric breakdown in the insulating surface film of the iron core, causing damage between the laminated electrical steel plates. Short circuit. As a result, iron loss,
Therefore, this has the opposite effect of increasing eddy current loss. Therefore, it is better not to apply the linear microstrain 18 over the entire surface of the electric iron plate. Furthermore, applying linear minute strain 18 to the entire surface of the electric iron plate requires unnecessary work and is uneconomical. In addition, if the linear microstrain 18 is to be applied only partially, a linear microstrain introducing device (not shown) can be added to the electric iron plate cutting device (not shown) to apply the linear microstrain 18 at the same time as cutting. It is possible to easily impart minute strain 18 and is extremely economical.

As described above, according to the present invention, a linear minute strain is generated in the direction perpendicular to the magnetic flux passing through the connecting part of the outer leg iron of the electromagnetic induction equipment core and the yoke only in the connecting part. The present invention has the effect of economically providing an electromagnetic induction equipment core with good characteristics, especially with reduced iron loss, by using a core piece made of an electric iron plate formed in such a manner as to provide the iron core. .

[Brief explanation of the drawing]

Fig. 1 is a plan view showing an example of a conventional electromagnetic induction equipment iron core, Fig. 2 is an explanatory diagram showing the rotating magnetic flux generated at the joint portion of the leg iron and yoke of the conventional electromagnetic induction equipment iron core, and Fig. 3 The diagrams show the building factors of iron loss in the core of electromagnetic induction equipment in Figure 1. The upper row shows a highly oriented silicon steel sheet, the lower row shows an explanatory diagram for a grain-oriented silicon steel sheet, and Figure 4 shows the electromagnetic induction of the present invention. A plan view showing an embodiment of the device core, FIG. 5 is a plan view of each core piece constituting the electromagnetic induction device core, and FIG. 6 is a magnetic flux distribution diagram at the connection between the outer leg iron and the yoke. Figure 7 is an iron loss distribution diagram with respect to the angle of minute strain with respect to the rolling direction when magnetized in the direction perpendicular to the rolling direction (C direction) and in the rolling direction (L direction), and Figure 8 is the electromagnetic distribution diagram of Figure 4. FIG. 3 is an explanatory diagram showing the improved iron loss building factor of the induction equipment core. 1, 2, 11, 12...Outer leg iron (leg iron), 3,
13... Central leg iron (leg iron), 4, 5, 14, 15
... Upper yoke (yoke), 6, 7, 16, 17... Lower yoke (yoke), 8, 1a, 4a... Alternate magnetic flux, 9
a, 9b, 9c... Rotating magnetic flux, 11a, 12a...
... Outer yoke core piece, 18 ... Linear minute strain, 1
3a...Central leg iron core piece, 14a, 15a...
Upper yoke iron core pieces, 16a, 17a... lower yoke iron core pieces.

Claims (1)

[Scope of utility model registration request] In an electromagnetic induction equipment core consisting of a leg iron and a yoke, a linear minute strain is applied to the mutually connecting portion of the outer leg iron and yoke in a direction perpendicular to the magnetic flux passing through that portion. Characteristic electromagnetic induction equipment core.