JPS641923B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a laminated outer iron core, and more particularly to an outer iron core lamination for a transformer.

[Technical background of the invention and its problems] Generally, E1 type core layers are widely used for outer iron type cores. EI type core lamination is E
Since the I-shaped member can be obtained from the same material as the character-shaped member, there is no waste and there is an advantage that it can be manufactured economically. Regarding such EI type core lamination,
For example, it is disclosed in US Pat. No. 3,546,571.

In general, an external iron transformer consists of a laminated iron core and a winding (copper wire) wound around a central leg iron. In the case of conventional EI type core stacks, the width of the magnetic flux path is the same everywhere. That is, each width of the outer leg iron, the width of the integral yoke, the width of the separated yoke, and the half width of the center leg iron are all the same. (Since the center leg iron width has two magnetic flux paths, that is, the magnetic flux path of the right magnetic circuit and the magnetic flux path of the left magnetic circuit,
It is twice the width of the outer leg iron, integral yoke, and separate yoke. ) In addition, in the conventional EI type core lamination, when multiple layers are stacked with the arrangement of the E-shaped member and I-shaped member reversed in each layer, the end of the outer leg iron of the E-shaped member and the I-shaped member are
The seams with the side edges of the letter-shaped members are aligned with the end faces of the window. That is, in the arrangement of the E-shaped members and the I-shaped members in each core layer, a pair of windows formed by each core layer is larger than a corresponding pair of windows in the adjacent core layer. They are arranged symmetrically when viewed from the superposition plane.

These seams always have small air gaps.
Therefore, at the edge of the window of the core in which the E-shaped members and I-shaped members in each layer are stacked in reverse order, only every other core with low magnetic resistance exists, and the effective The cross section is only half of the other parts.

The magnetic permeability of the space is 1, and the magnetic resistance is orders of magnitude higher than that of iron core materials. As a result, the flow of magnetic flux in the joint portion tends to avoid the joint and pass through the adjacent layer. Therefore, the magnetic flux density in the core layer adjacent to the joint is twice that elsewhere. In other words, the magnetic flux for two layers is concentrated in the layer adjacent to the joint, so when viewed from the entire laminated core, this part has the disadvantage of being saturated with half the magnetic flux density of the other parts.

For this reason, the magnetization curve of a conventional external iron transformer is
As shown in FIG. 4, a bending point occurs near half the magnetic saturation value of the material, resulting in an increase in magnetizing current and magnetic leakage.

Other transformer cores include a rim that connects an upper yoke and a lower yoke each made of different steel plates, and the joints between the steel plates of the yoke and the steel plates of the rim are placed at the same position in every other layer. There is a laminated iron core in which the outer ends of the upper and lower yokes are stacked to form aligned end surfaces (for example, Utility Model Application No. 47-25706). In FIG. 5, 11, 12 and 21 are yokes;
and 22 are made of wide steel plates, and 21 is made of narrow steel plates. 37, 38, 39
is a rim connecting the upper yoke 11 and the lower yoke 21.

However, in the case of this core, there are a total of six seams, three at the top and three at the top and bottom in each layer. Of these, seams 44, 46, 54, 55, 5
6 is formed within the yoke part by being covered with a wide yoke, but the seams 41, 4
2, 43, 54, 55, and 56 are covered by the rims 37, 38, and 39 as shown in FIG. 5, so that a seam is formed in the leg iron portion. For this reason, the laminated core shown in FIG. 5 produces an inflection point similar to the conventional DC magnetization curve shown in FIG.

[Object of the Invention] The object of the invention is to improve the magnetic resistance of the magnetic circuit by reducing the magnetic resistance of the outer leg iron and the integral yoke, and to further improve the local saturation of the magnetic flux path caused by the joints. It is an object of the present invention to provide an outer iron core lamination that can increase the efficiency of a transformer, reduce magnetic leakage, and reduce magnetizing current.

[Summary of the Invention] According to the laminated outer iron type iron core of the present invention, an E-shaped structure consisting of an integral yoke, a center leg iron, and first and second outer leg irons parallel to the center leg iron and spaced apart from each other by a certain distance. and an I-shaped member acting as a separation yoke and made of the same material as the E-shaped member, the E-shaped member and the I-shaped member being connected to the first and second outer legs. The ends of the iron and the end of the center leg iron are arranged so as to have a seam between them and the side edge of the I-shaped member to form one iron core layer,
A plurality of these single layers are stacked with the E-shaped members and I-shaped members in each layer reversed in arrangement. In this case, the width C1 of the integral yoke is larger than the width C2 of the separated yoke C2, so that in the arrangement of E-shaped members and I-shaped members in each core layer, a pair of The window is arranged asymmetrically (disposed offset in the longitudinal direction of the leg iron) when viewed from the overlapping plane of the iron core layers with respect to a corresponding pair of windows of adjacent iron core layers. Therefore, the separation yoke is wrapped between adjacent integral yokes to fit within the width of these integral yokes, and the width C1 of the integral yoke is larger than 1/2 of the width f of the center leg iron (C1>f /
2) Furthermore, the width b of the first and second outer leg irons is larger than 1/2 of the width f of the center leg iron (b>f/2).

[Embodiment of the Invention] An embodiment of the invention will be described below with reference to the drawings.

Figure 1 shows the EI type core stack of an external iron type transformer.
This EI type core stack is composed of an E-shaped member A and an I-shaped member B. The E-shaped member A is composed of an integral yoke 5, a center leg iron 1, and outer leg irons 2 and 3 parallel to the center leg iron 1 and spaced a certain distance apart. The I-shaped member B forms a separation yoke 4. The E-shaped member A and the I-shaped member B are connected by a seam 8 between the ends of the first and second outer leg irons 2 and 3 and the end of the center leg iron and the side edge of the I-shaped member B. are arranged to form one core layer. Although the core layer of this embodiment is constructed so that the vertical and horizontal lengths a are equal, they do not necessarily have to be equal.

The distance between the central leg iron 1 and the outer leg irons 2, 3, ie, the width h of the window portions 10, 11, is equal to or larger than the width C2 of the separation yoke. This is E-shaped member B
(separation yoke 4), and is configured to minimize cutting loss of the E-shaped member when punched. In punching, two steel plates are simultaneously punched to form the E-shaped member A, but since the two steel plates are punched facing each other, an I-shaped member B (separation yoke 4) of the same length is obtained.

The integral yoke 5 of the E-shaped member A is seamlessly formed into three pieces, including the center leg iron 1 and the first and second outer leg irons 2 and 3. The width C1 of the integral yoke 5 is formed to be larger than the width C2 of the separation yoke 4.

Each width b of the first and second outer leg irons 2 and 3 is formed to be larger than 1/2 of the width f of the center leg iron 1. The width b of the first and second outer leg irons is 1/ of the center leg iron f.
It is desirable that the ratio is 1.2 to 1.3 times 2. or,
It is desirable that the sum of the width C1 of the integral yoke 5 and the width C2 of the separated yoke 4 is 1.3 to 1.4 times the width f of the central leg iron 1. The E-shaped member A and the I-shaped member B have a seam 8 between the ends of the first and second outer leg irons 2 and 3 and the end of the center leg iron 1 with the I-shaped member B. They are arranged like this to form one core layer. The internal length ek of a pair of windows formed when each core layer is stacked is longer than the length e of a pair of windows in each core layer due to the width C1 of the integral yoke 5 and the width C2 of the separated yoke 4. It is shorter by the difference (C1-C2). Therefore, in the arrangement of the E-shaped members and I-shaped members in each core layer, a pair of windows 10 and 11 formed by each core layer is different from a corresponding pair of windows in the adjacent core layer in the core layer. The leg irons 2 and 3 are arranged asymmetrically (shifted in the longitudinal direction of the leg irons 2 and 3) in terms of their superposition. The windows 10, 11 are therefore asymmetrical with respect to the horizontal axis 6.

As described above, since the width C1 of the integral yoke 5 is formed to be larger than the half width (f/2) of the center leg iron 1, the cross-sectional area of the outer leg iron becomes large. As a result, the magnetic resistance of the outer leg iron can be reduced.

Also, normally, the center leg iron 1 and the separation yoke 4 are punched out so as to face the direction of easy magnetization, but the integral yoke 5
is oriented perpendicular to this direction of easy magnetization.
Therefore, the magnetic resistance of the integrated yoke 5 is higher than that of the separate yoke. Therefore, the width C1 of the integral yoke 5
By making C2 larger than the width C2 of the separation yoke, the increased magnetic resistance can be compensated for.

According to the laminated outer iron type core of this invention, the outer leg iron width is larger than 1/21 of the center leg iron width, so the joint between the outer leg iron end and the separation yoke is similar to that of a conventional transformer with the same output. It is wider than the laminated iron core used for containers. As a result, the reluctance of these joints is reduced compared to conventional steel transformers.

Furthermore, silicon steel plate is generally used as the material for the core for external iron type transformers. Silicon steel plates include non-oriented silicon steel plates and grain-oriented silicon steel plates.

Non-oriented silicon steel sheets are cold rolled and are isotropic, meaning their crystals are oriented in various directions, so they exhibit the same characteristics no matter which direction a magnetic field is applied to them.

On the other hand, in the case of grain-oriented silicon steel sheets, hot rolling is followed by a combination of two or one cold rolling and intermediate annealing, followed by final annealing. This results in anisotropy, that is, the orientation of the crystals is aligned in the direction of rolling, so the properties in the direction perpendicular to rolling are slightly worse than non-directional. However, B-H in the rolling direction
It is known that properties other than the saturated region are significantly improved compared to non-oriented silicon steel sheets. This means that magnetization in the rolling direction has low magnetic resistance.

In addition, punching is generally performed so that the rolling direction is the longitudinal direction of the outer leg irons and the center leg iron. Since the magnetic flux lines of the integral yoke flow in a direction perpendicular to the rolling direction, magnetic resistance increases due to the magnetic flux path of the integral yoke. In this invention, by increasing the width of the integral yoke, it is possible to reduce the increased magnetic resistance due to the flow of magnetic flux lines in a direction perpendicular to the rolling direction.

The outer iron core shown in FIGS. 2 and 3 has the core laminations shown in FIG. 1 arranged alternately.
A side edge 12 of the integral yoke 5 is in contact with a winding (not shown). Conversely, the side edge 15 of the separation yoke 4 is C1
It is separated from the winding by a distance of -C2. or,
The internal length ek of the windows 10 and 11 is configured to be shorter by C1-C2 than the window length e in each core layer.

When a plurality of iron core layers in which the width C1 of the integral yoke is larger than the width C2 of the separated yoke are stacked with the arrangement of the E-shaped members and I-shaped members in each layer reversed,
The design is such that the width of the seamless core layer is increased while the width of the seamed core layer is reduced, leaving the total cross-sectional area unchanged. That is, the pair of windows 10 and 11 formed by each core layer are arranged asymmetrically with respect to the corresponding pair of windows in the adjacent core layer when viewed in terms of the superposition of the core layers, so that the separation yoke 4 is wrapped within the width of the integral yoke 5. In this case, the position of the joint is not in contact with the edge of the window as in the conventional EI iron core, but is moved parallel to the inside of the yoke by C1-C2, so the cross section of the magnetic circuit (at right angles to the magnetic path) cross section). Therefore, the influence of seams can be eliminated. In other words, a bypass is formed for the magnetic flux that cannot cross the joint, and the disadvantage that the magnetic flux of two layers concentrates on the layer adjacent to the joint, resulting in saturation at half the magnetic flux density, as seen in the prior art. Can be removed.

As a result, according to this invention, as shown in FIG. 4, the inflection point that occurs in the magnetization curve of the conventional iron core lamination due to the leg iron being saturated at about half the magnetic saturation value of the material has been eliminated. do not have. In other words, the magnetization curve is almost close to that of the material itself, and the influence of the seam does not appear on this magnetization curve.

Furthermore, the main cause of magnetic leakage in conventional transformers is that magnetic flux is forced to pass through joints with high magnetic resistance. In the core lamination of the present invention, the magnetic resistance itself is lowered by improving the joint position, so there is less leakage, and since the core is wrapped within the adjacent yoke, influence on the outside is prevented.

Additionally, edge burrs caused by punching have the negative effect of increasing seam gaps, but this effect can be minimized.

In addition, according to the applicant's experimental results, when the width of the integral yoke 5 without a joint is increased by 5% compared to the width of the separated yoke 4 with a joint, good magnetic and electrical characteristics can be obtained, and when the width is increased by 10%. Even better results were obtained, with a 20% increase giving the best results.

The applicant also measured the excitation VA curves of the conventional laminated core shown in FIG. 5 and that of the present application. The results are shown in FIG. As is clear from FIG. 6, when the excitation is the same, the magnetic flux density of the laminated core of the present application is greater than that of the laminated core shown in FIG. 5. As a result, the magnetic resistance of the present invention is lower than that of the laminated core shown in FIG. 5, and therefore, for example, when a transformer with the same output is manufactured using the laminated core of the present invention and the laminated core of FIG. When the laminated core of the present application is used, the size of the transformer can be made smaller.

After inserting the windings, the E-shaped member A and the I-shaped member B are fixed with cement, tightened with glazing or the like, or welded. Such processing is effective when the manufacturing process has priority over electrical characteristics.

[Effects of the Invention] As described above, according to the outer iron type core lamination of the present invention, the E-shaped member and the I-shaped member are connected to the ends of the first and second outer leg irons and the end of the center leg iron. Part I
A single core layer is formed by arranging the E-shaped members and the I-shaped members so as to have a seam between them and the side edges of each layer, and this single layer is laminated in multiple layers by reversing the arrangement of the E-shaped members and I-shaped members in each layer. In the outer iron core stack, the width C1 of the integral yoke is larger than the width C2 of the separated yoke. Therefore, in the arrangement of E-shaped members and I-shaped members in each core layer, the window formed by each core layer is in the overlapping plane of the core layer with respect to the corresponding window in the adjacent core layer. The separating yokes are arranged asymmetrically in view and are wrapped between adjacent integral yokes to fit within the width of these integral yokes. Therefore, it is possible to eliminate local saturation of the magnetic flux path caused by the joint between the E-shaped member and the I-shaped member, reduce magnetic leakage in the axial direction of the winding, and reduce magnetic resistance and magnetization conduction. I can do it.

[Brief explanation of drawings]

Fig. 1 is a plan view of an EI type core lamination showing one embodiment of the present invention, Fig. 2 is a plan view of an outer iron type core composed of alternately laminated EI type core laminations,
The figure is a side view of the outer iron core shown in the direction of the arrow in Figure 2, and Figure 4 is a DC magnetization characteristic diagram and dynamic effective magnetization induction hysteresis of the laminated core of the present invention and the conventional laminated iron core. FIG. 5 is a plan view showing an example of a conventional laminated core, and FIG. 6 is a characteristic diagram showing an excitation VA curve of the conventional laminated core shown in the present application and FIG. 1... Center leg iron, 2, 3... Outer leg iron, 4...
Separate yoke, 5...Integrated yoke, 6...Horizontal shaft, 8
... Seam, 9 ... Vertical axis, 10, 11 ... Window, 1
2... side edge of integral yoke 5, 15... side edge of separated yoke 4.

Claims (1)

[Scope of Claims] 1. An E-shaped member consisting of an integral yoke, a central leg iron, and first and second outer leg irons that are parallel to the central leg iron and spaced apart by a certain distance; an I-shaped member made of the same material as the E-shaped member, and the E-shaped member and the I-shaped member are connected to the ends of the first and second outer leg irons and the center leg iron. The ends are arranged with a seam 8 between the side edges of the I-shaped members to form one core layer, and this single layer is combined with the arrangement of E-shaped members and I-shaped members in each layer. In an outer iron core stack in which multiple layers are stacked in reverse order, the width C1 of the integral yoke is larger than the width C2 of the separation yoke (C1>C2), and as a result, the E-shaped member and In the arrangement of the I-shaped members, a pair of windows formed by each core layer is arranged such that a pair of windows formed by each of the core layers corresponds to a pair of windows in an adjacent core layer.
They are arranged asymmetrically when viewed from the overlapping plane of the core layers,
The separation yoke is wrapped between adjacent integral yokes to fit within the width of these integral yokes, and the width C1 of the integral yoke is larger than 1/2 of the width f of the central leg iron (C1>f /2),
Further, the width b of the first and second outer leg irons is larger than 1/2 of the width f of the center leg iron (b>f/2).
This is an outer iron core laminated iron core. 2. The outer iron core stack according to claim 1, wherein the width C1 of the integral yoke is at least 5% larger than the width C2 of the separation yoke. 3. Claims 1 to 3, characterized in that the sum of the width of the integral yoke and the width of the separated yoke (C1+C2) is at least 1.3 times, and at most 1.4 times, the width f of the central leg iron. Laminated outer iron core according to any of item 2. 4. The width b of the first and second outer leg irons is at least 1.2 times the width f of the center leg iron, and is at most
The laminated outer iron core according to any one of claims 1 to 3, characterized in that the laminated outer iron core is 1.3 times as large. 5. The device according to any one of claims 1 to 4, wherein the width h of the first and second window portions is at least equal to the width C2 of the separation yoke (h>C2). Laminated steel core. 6. The width C2 of the separation yoke is at least 1/2 (C2>f/2) of the width f of the central leg iron, according to any one of claims 1 to 5. Laminated outer iron core. 7 1 formed when the above-mentioned core layers are overlapped
The internal length ek of the pair of windows is shorter than the length e of the pair of windows in each core layer by the difference (C1-C2) between the integral yoke width and the separated yoke width. The outer iron core laminate according to any one of items 1 to 6.