JPS5939012A - Core of stationary electric induction apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an iron core for a stationary induction electric appliance, and more particularly to an iron core for a stationary induction electric appliance, which is an iron core made of a plurality of turns of a thin metal plate, and has a cut portion at at least one of the cores.

Metal thin sheets, such as amorphous magnetic alloys, which are a type of magnetic metal thin strip, have a loss that is less than 1/3 that of silicon steel sheets, so they are promising for reducing loss in transformers and are shown in Figures 1 to 6. As shown in the figure, research and development is being carried out on dams for use in transformer cores. There are two methods for producing a transformer using a wound core, that is, a wound core.The so-called no-cut method involves manufacturing the wound core and then wrapping the windings and fixing them using an insulator. , its cut portion, that is, cut portion 2
There is a so-called cut core method (see FIG. 1) in which the winding 3 is inserted from the inside and fixed with an insulator 4. In this cut core method in which the cut portion 2 is provided at one location on the wound core 1, it is relatively easy to obtain a sufficiently good magnetic bond at the cut portion 2 for a relatively thick metal strip such as a silicon steel plate. be. However, with thin metal plates such as magnetic metal ribbons made of ultra-thin amorphous magnetic alloy, it is difficult to obtain good magnetic bonding at the cut portion 2, and the bonded portion may be slightly misaligned or the bonded portion may be slightly damaged. It was found that the loss changes greatly due to the formation of voids. Cutting methods in such a cut core method include a method in which the cut portion 2 is formed linearly (see Figure 2), and a method in which the cut portion 2 is formed diagonally by shifting each magnetic metal ribbon at a predetermined interval (see below). , a butt bonding method (see FIG. 3) and a step-forming method (hereinafter referred to as a step-wrap method, see FIG. 4).

By the way, when manufacturing the wound core 1 using an ultra-thin magnetic metal ribbon, the cut portion 2 may be slightly misaligned (see Fig. 5), unlike silicon steel plates, etc., as described above.
However, this problem mainly occurs in the method of forming the cut part 2 linearly and the knot joining method, and is relatively rare in the step lap method.In this butt joining method (see Figure 5), the laminated part Up.

Sometimes the lower part is misaligned, but most often only the upper part or the lower part is. For example, if you assemble the lower parts together, the upper part will be misaligned, but this is because the magnetic metal ribbon is very thin. That is, since the magnetic metal ribbon is very thin, a slight difference in clamping pressure causes a deviation, and this deviation changes the iron loss as described below.

When the laminated part of the magnetic metal ribbons (see Fig. 6), which is misaligned with the cut part 2 as the boundary, is separated into the left part 5 and the right part 6 in the figure, it was found that the layer was flowing in the outermost layer of the right part 6. Since the magnetic flux 7 also flows through the outermost layer of the left portion 5, it flows across the inner layer of the left portion 5, as indicated by the arrow in the figure, and reaches the outermost layer. The same goes for other layers.
traverses the magnetic metal ribbon, an eddy current (not shown) flows through the magnetic metal ribbon in the inner layer, increasing loss. However, the misalignment that increases such loss brings about inconsistencies in the magnetic flux density distribution within the magnetic metal ribbon, and is one of the causes of magnetostriction, which also increases the exciting current. There is. One possible way to reduce this gap is to place the insulator 4 between the winding 3 and the wound core 1 (see Figure 1). Even if the surfaces are aligned, it is difficult to align the outer edges for the reasons mentioned above, and they often deviate slightly.Therefore, a thin metal plate such as this kind of magnetic metal ribbon made of ultra-thin amorphous magnetic alloy is used for the transformer core. In order to achieve this goal, a major challenge was how to reduce this shift and reduce loss.

The present invention has been made in view of the above points, and its purpose is to provide an iron core for a stationary induction electric appliance that enables loss reduction.

That is, in the present invention, the cut portion arranges a predetermined plurality of thin metal plates on one side and a plurality of predetermined gold Thk plates on the other side through a gap between the cut portions, and a gap between the thin metal plates. It is characterized in that a spacer stronger than a thin metal plate is placed across the gap.

The present invention will be explained below based on the illustrated embodiments. An embodiment of the present invention is shown in FIGS. 7 and 8. Note that parts that are the same as those in the conventional model are given the same reference numerals, and therefore their explanations will be omitted. In this embodiment, the cut portion 2a is arranged such that one predetermined plurality of metal thin plates 8 corresponds to the other predetermined plurality of metal thin plates 9 through the gap between the cut portions 2a. A spacer 10 having a stronger strength than a thin metal plate was placed across the gap between 8 and 9.

By doing so, the cut portion 2a without any deviation is formed, and it is possible to obtain an iron core for a stationary induction electric appliance that enables loss reduction.

That is, after cutting one part of the wound core 1a, this cut part 2a is made to stand up once, and the winding 3 is inserted into the wound core 1a from this cut part 2a, and the left part 5 of the laminated part cut after insertion is
A predetermined plurality of thin metal plates 8, for example, a magnetic metal thin strip made of an amorphous magnetic alloy, and a predetermined plurality of metal thin plates 9, for example, a magnetic metal thin strip, of the right part 6 are butted against each other, and a butted portion is formed on the butted surface. A spacer 10, for example, an insulating plate 10a, which is stronger than the magnetic metal ribbon, is placed across the spacer. Then, this process was repeated in order to form the cut portion 2a. In this way, the insulating plate 10 is stronger than the magnetic metal ribbon.
a is arranged, there is no longer any deviation in the slightly clamping pressure surface of L as in the conventional case, and the outermost surface layers of the right part 6 and left part 5 of the cut part 2a are now facing each other, The magnetic flux 7 now flows in a direction perpendicular to the lamination direction as shown by the arrow in the figure, so that there is no magnetic flux that crosses the inner layer as in the conventional case, and eddy currents do not flow. However, losses can be reduced.

In this embodiment, the insulating plate 10a is used as the spacer 10, but if a magnetic material with high magnetic permeability such as a silicon steel plate is used instead of the insulating plate 10a, the insulating plate 10a can be used for the cut portion 2a. Since the increased air gap is occupied by the magnetic material, the air gap is compensated by the magnetic material, and the excitation current can be reduced.

Another embodiment of the invention is shown in FIG.

In this embodiment, the present invention is applied to a product cut using a linear cutting method. In this case as well, the same effects as in the above case can be achieved.

FIG. 10 shows yet another embodiment of the invention.

This example is applied to a product cut by the step wrap method, and an insulating plate 10a is inserted at a location B where the step changes rapidly.

By doing so, the loss can be reduced. In other words, the step-wrap method has the feature that the laminated portion of the magnetic metal ribbon does not shift between the left part 5 and the right part 6 of the cut part 2a, but in the part B of the step-wrap where the step changes rapidly, the left part The opposing area of the lap part between the magnetic metal ribbon 5 and the magnetic metal ribbon 6 on the right side is smaller than other parts, and the amount of magnetic flux flowing through this lap part is large. Since the insulating plate 10a is inserted between the insulating plates 10a, the amount of magnetic flux flowing between the insulating plates 10a can be reduced, and loss can be reduced.

Although not shown in the present invention, since the cut portions 2a are all wrapped and tightened using insulating tape or the like, the spacer 10 to be inserted should be removed without applying excessive force to the magnetic metal ribbon. It is desirable to do so-called corner cutting.

As described above, in the present invention, a spacer with greater strength than the thin metal plates is inserted between the thin metal plates of the cut portion, spanning the gap between the cut portions, so that unlike the conventional method, misalignment does not occur due to a slight difference in clamping pressure. As a result, the thin metal plates on the left and right sides of the cut portion are aligned and correspond to each other, preventing the flow of eddy current, making it possible to obtain an iron core for stationary induction appliances that can reduce loss.

[Brief explanation of drawings]

Figure 1 is a vertical side view of a conventional cut-core type transformer of a stationary induction electric appliance, and Figures 2 to 4 are vertical side views showing the different states of cut parts of the iron core of a conventional stationary induction electric appliance. , FIG. 5 is a vertical side view showing the state of misalignment of the cut portion of the core of a conventional stationary induction appliance, FIG. 6 is an enlarged view of the A-frame part in FIG. 5, and FIG. 7 is a stationary induction appliance of the present invention. FIG. 8 is a longitudinal sectional side view showing the formation of the cut section of a cut core type transformer according to an embodiment of the iron core, FIG. 8 is a longitudinal sectional side view of the cutting section of the embodiment, and FIG. FIG. 10 is a longitudinal sectional side view of the cutting section of another embodiment of the iron core of the stationary induction appliance of the present invention. FIG. la...Wound core, 2a...Cut part, 8, 9...
Multiple-sheet funeral 2/Figure 3 Figure 1 Figure 5 Funeral 6 Figure 8

Claims (1)

[Scope of Claims] 1. In an iron core to which a winding of a stationary induction appliance is attached, which has a cut portion at least one of which is wound with a plurality of thin metal plates, one of the plurality of thin plates is wound through a gap between the cut portions. The other plurality of metal thin plates are arranged correspondingly to the metal thin plate, and a spacer having greater mechanical strength than the metal thin plate is arranged between these plurality of metal thin plates, spanning the gap. Iron core of stationary induction electric appliances. 2. The iron core for a stationary induction electric appliance according to claim 1, wherein the spacer is made of a magnetic material. 3. The iron core for a stationary induction electric appliance according to claim 1, wherein the spacer is made of an insulator. 4. The iron core for a stationary induction electric appliance according to claim 1, wherein the thin metal plate is made of an amorphous magnetic alloy.