JPH0644535B2 - Stationary induction electric iron core - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a stationary induction electric iron core, and more particularly to improvement of a core punching structure of a power transformer.

[Technical background of the invention and its problems]

In general, a stationary induction electric iron core such as a transformer or a reactor, for example, a power transformer iron core (hereinafter abbreviated as an iron core) is formed by stacking thin frame-shaped silicon steel strips (hereinafter referred to as iron core blanks) into a substantially circular shape. It forms a close cross-section, and the main leg, side legs, and part called a yoke form a magnetic path.

Further, the main leg and the yoke and the like are joined by appropriately wrapping the respective core blanks.

As shown in FIG. 6, it comprises two main legs 1 and an upper yoke 3 and a lower yoke 4 for magnetically coupling the respective main legs 1.
The main landing gear 1, the upper yoke 3, and the lower yoke 4 are fixed between the core punched plates by a fastening tape 5 made of glass fiber having a thermosetting property as a base material around the stacked core punched plates. It is tightened to obtain the tightening pressure. Also, the main landing gear 1
The blank lap joint 10 of the upper and lower yokes 3, 4 is formed by lapping several core blanks with a constant width.

In FIG. 7, the cross section of the main landing gear 1 is formed by stacking several kinds of core blanks having different widths, and has a cross sectional shape that is inscribed in a circle. In this way, in order to wrap and join the core punched plate at the blank lap joint 10 of the main leg 1 and the upper and lower yokes 3, 4, it is necessary to devise the structure of the core blank.

FIG. 8 and FIG. 9 show an example of an iron core punching plate configuration that constitutes the single-phase two-leg iron core of FIG. An iron core punching plate 7 for a yoke and an iron core punching plate 8 for a main leg are joined together in a frame shape to form two types of frame-shaped iron core punching plate configurations as shown in FIGS. 8 and 9. .

FIG. 10 shows an assembled state of the single-phase two-leg iron core of FIG. First, in the main leg 1, the core punched plates of the main leg portions are stacked in accordance with the configuration patterns of the core punched plates shown in FIGS. 8 and 9, and are fastened and fixed by the fastening tape 5. Next, insert several core blanks 7 for the lower yoke into the end face of the main leg 1 in order to assemble the lower yoke 4, insert a coil (not shown) into the main leg 1, and then insert the core for the upper yoke. Similar to the lower part, the punched plates 7 are inserted into the upper yoke 3 to form the upper yoke 3. At this time, assembling the upper and lower yokes 3, 4 requires a lot of assembling time because the iron core blanks are manually inserted into the end surface of the main leg 1 by an operator as described above. This requires skilled skills of the operator.

No. 11 is a sectional view taken along the line XI-XI of FIG. 6 and shows the flow of magnetic flux at the joint where the core punching plates are wrapped. 11th
In the figure, for example, two iron core punched plates are wrapped and joined with a constant width. Also in FIG. 8 and FIG. 9, the iron core blanks are cut into a trapezoidal shape and joined to each other in a frame shape. However, the abutting portion is not completely abutted due to the cutting dimension accuracy of the core punched plate, the assembly accuracy of the main leg spacing, and the like, and in reality there is a slight gap between the core punched plates.

An arrow 15 indicates the flow of the magnetic flux when the air gap 12 is present at the butting portion of the core punched plate. (See Fig. 11) Thin 1
When the magnetic flux reaches the air gap 12 after flowing through the iron core punched sheets 11, the magnetic resistance of the air gap 12 is large, so that the air flux bypasses the air gap 12 and flows into the adjacent iron core punched plate 11. At this time, since the flow of the magnetic flux generates a component perpendicular to the core punched plate, a large amount of eddy current loss is generated as compared with the case where the magnetic flux flows parallel to the core punched plate 11. Further, since the iron core punching plate 11 on the side where the magnetic flux flows has an originally constant magnetic flux amount, the magnetic flux density locally increases, leading to an increase in loss.

Further, when there are severe restrictions on transportation weight, transportation size, etc., there is a concept of disassembly transportation in which an iron core, a coil, a tank, and others are separately transported to assemble a transformer on site. However, as mentioned above, when assembling the iron core, it takes time to assemble the yoke part, and during that time the insulator such as the coil absorbs moisture, which adversely affects the insulation characteristics. It had to be processed.

[Object of the Invention]

The present invention has been made in consideration of the above points, and an object of the present invention is to obtain a core structure which is easy to assemble and which can reduce a loss generated at a joint portion of the core. To provide.

[Outline of Invention]

According to the present invention, in order to achieve such an object, the main leg, the side leg, the yoke, etc. are individually formed by fastening with a fastening tape, and when these end faces are joined to each other, the respective iron cores are formed. The cutting angles and shapes of the iron core punching plates are appropriately determined so that the end faces of the iron core punching plates are aligned and stacked so that the punching plates are evenly fitted, and when they are joined to each other, they are vertical. In addition, when joining the main leg, side legs, yoke, etc., the transformer iron core is constructed by joining the joining surfaces with an adhesive substance for bonding the surfaces to each other. It is characterized by reduced loss.

Example of Invention

An embodiment of the static induction iron core of the present invention will be described below with reference to FIGS. 1 and 2. The same parts as those in FIGS. 10 and 11 are designated by the same reference numerals. Stationary induction electric iron cores such as transformers and reactors, for example, inner iron type single-phase 2 of transformer cores
The leg iron core is composed of two main legs 1, an upper yoke 3 and a lower yoke 4. The main leg 1, the upper and lower yokes 3 and 4 are fixed by tightening with a tightening tape 5 by aligning the end faces of the iron core blanks constituting each. Further, the shape of the blank is determined so that each joint surface becomes vertical when they are joined to each other.

When assembling the transformer core, the separately assembled main leg 1, upper yoke 3 and lower yoke 4 are joined at the adhesive surface 6 via the adhesive substance 13. This adhesive substance is, for example, a sheet coated or impregnated with an adhesive. Further, a thermosetting adhesive sheet may be used, and an adhesive having an adhesive effect at room temperature, an adhesive having a higher magnetic permeability than air, or the like. Although not shown in FIG. 1, in order to improve the mechanical strength of the joint portion of the iron core, which is similar to the conventional iron core structure, an iron core tightening fitting such as a so-called clamp or a backing plate is provided around the iron core. is doing. If necessary, the iron core tightening metal fitting can be combined with the iron core punching plate when tightening the iron core blanking plate with a fastening tape, and then the outer circumference thereof can be fastened and fixed.

Next, another embodiment of the present invention will be described with reference to FIGS. The same parts as those in FIG. 1 are designated by the same reference numerals.

FIG. 3 shows another first embodiment of the present invention. That is, in the single-phase three-leg iron core, the main leg 1, the side leg 2, the upper yoke 3, and the lower yoke 4 which are independently and individually clamped and fixed by the fastening tape 5 are bonded to each other on the bonding surface 6 via the bonding substance. It is joined.

FIG. 4 shows another second embodiment of the present invention. That is, in the three-phase three-leg iron core, the central main leg 1 is joined to the upper and lower yokes 3, 4 formed by stacking V-shaped notched iron core plates at the adhesive surface 6 via an adhesive substance. .

Furthermore, FIG. 5 shows another third embodiment of the present invention. That is, in the three-phase five-leg iron core, the central three main legs 1 are joined to the upper and lower yokes 3 and 4 formed by stacking V-shaped notched iron cores at the adhesive surface 6 via an adhesive substance. ing.

As described above, according to the present embodiment, when assembling, for example, a transformer core such as a static induction core, after assembling the main leg and the side legs, the number of core punching plates for assembling the upper and lower yokes is increased. There is no need to insert the main and side legs one by one.
That is, it is possible to easily join the upper and lower yokes, which are assembled and assembled in advance, to the main leg and the side leg, and it is possible to greatly simplify the assembling work. Further, since the joining surfaces are joined by an adhesive substance having a strong adhesive force, not only sufficient mechanical strength is obtained, but also vibration and noise generated due to magnetic attraction are reduced.

As shown in FIG. 2, the iron core punched plate 11 has the end faces aligned and joined via an adhesive substance 13 to form an adhesive face 6. The arrow 16 in the figure indicates the flow of magnetic flux in the core punched plate 11. It can be seen that the magnetic flux smoothly flows between the core punched plates 11 aligned in this way.

Therefore, according to the present embodiment, it is possible to reduce the loss at the joint portion without causing an increase in loss due to the disturbance of the flow of the magnetic flux at the joint portion of the iron core blank. In addition, the transformer has severe transport restrictions, and when disassembling and transporting the contents of the transformer into coils and iron cores and assembling and disassembling the contents at the site, the main components such as the main landing gear and yoke are required beforehand. It is possible to drastically reduce the time required to assemble the iron core on site because the iron core assembled by transporting the assembled parts to the site and assembling the individual parts appropriately. Since it does not take much time to assemble the iron core, the rate at which the insulator such as the coil absorbs moisture is small, and the influence on the insulating characteristics is small. Therefore, it is not necessary to carry out a large-scale drying process locally.

Further, the transformer iron core according to the present embodiment has a slight gap at the joint portion of the iron core punching plate, so that the magnetic resistance of the magnetic path through which the magnetic flux flows increases somewhat. This is a great advantage for converter transformers used for DC transmission. In such a transformer for a converter, since a current having a slight DC component flows in the DC winding, a DC magnetic flux is generated in the iron core, which causes an increase in the magnetic flux density. In the transformer iron core of this embodiment, since the magnetic resistance of the iron core is large, it is possible to reduce the generation of DC magnetic flux due to DC current.

〔The invention's effect〕

As described above, according to the present invention, the assembly work has a remarkable practical utility in the field of assembly work, especially in the field of assembly work. It is extremely useful and significant in improving the efficiency of.

[Brief description of drawings]

FIG. 1 is a plan view of the assembly of a static induction iron core of the present invention, FIG. 2 is an explanatory view showing the flow of magnetic flux at the joint portion of the core punched plate of FIG. 1, and FIGS. FIG. 6 is a plan view of another embodiment of the invention, FIG. 6 is a plan view of a conventional single-phase two-leg iron core, FIG. 7 is a sectional view taken along the line VII-VII in FIG. 6, and FIGS. Fig. 6 is a plan view showing the assembly of the core punched plate of Fig. 6, Fig. 10 is a plan view of the assembly of the conventional transformer core, and Fig. 11 is a flow diagram of the magnetic flux at the joint of the core punched plate of Fig. 10. FIG. 1 ... Main leg, 2 ... Side leg, 3 ... Upper yoke, 4 ... Lower yoke, 5 ... Tightening tape, 6 ... Adhesive surface, 7,8,11.

Claims (4)

[Claims] 1. A static induction electric iron core having an iron core punching structure in which thin silicon steel strips are joined together in a frame shape. In a joining surface where the iron punching plates are butted and joined together, all of the iron core punched sheets are joined together. After setting both frame-shaped core punching shapes so that they are evenly fitted and joined vertically, the main leg, side legs, and upper and lower yokes are independently fixed beforehand with tightening tape, and then these A static induction electric iron core, characterized in that the joint surfaces of the can be assembled and joined together by interposing an adhesive substance. 2. The joint surface between the main leg and the upper and lower yokes has a V-shaped notch in the core punching plate of the upper and lower yokes, and the joint surface with the main leg is V-shaped. The static induction electric iron core according to claim 1. 3. The static induction electric iron core according to claim 1, wherein the adhesive substance interposed on the joint surface is an adhesive sheet having a thermosetting property. 4. The static induction electric iron core according to claim 1, wherein the adhesive material has a higher magnetic permeability than air.