JPS6248364B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved structure in which an ultra-thin electromagnetic steel sheet is used in a non-cut wound core used in small transformers and instrument transformers.

In general, small transformers such as distribution transformers of 500 KVA or less and pole transformers are wound with grain-oriented silicon steel plates approximately 0.3 to 0.35 mm thick in the direction of magnetic flux in order to reduce no-load loss. A rolled iron core is used. The shape of the wound core is roughly divided into three types: C-cut core, one-turn cut core, and non-cut core. C-cut cores and one-turn cut cores are used in transformers that have a core attached to a pre-fabricated winding, while non-cut cores are used in transformers that have a winding wrapped around a pre-fabricated core. Non-cut cores are often used in small transformers of 500KVA or less and instrument current transformers due to their economical aspects. Figure 1 shows an external front view of an example of a conventional non-cut core wound core.
A cross-sectional view of the A-A section is shown in FIG. Overall code 1
The wound core shown by is a three-block core 2-1, 2-
2, 2-3, and the overall cross-sectional shape is inscribed in a circle as shown in FIG. Each block iron core 2-1, 2-2, 2-3 is thin, that is, the thickness is 0.3
It is made by winding and laminating grain-oriented silicon steel plates with excellent magnetic properties in the rolling direction of ~0.35mm. The specific manufacturing method is as follows. That is, although not shown, the grain-oriented silicon steel plate 2-1 of the first block having a predetermined width is wound around a core having predetermined dimensions to a predetermined thickness. A grain-oriented silicon steel plate 2-2 of a predetermined width and a predetermined thickness of the second block is wound thereon. Furthermore, the grain-oriented silicon steel plate 2-3 of the third block is wound on top of this, and the end of the winding is fixed by spot welding or the like. Next, the core and the core are placed in an annealing furnace at about 800° C. and annealed for a predetermined period of time. When the core is removed, a non-cut wound core as shown in FIGS. 1 and 2 is completed. When winding a wire around this wound core 1, insulating tape is wrapped around the legs to prevent the core from deforming.
The grain-oriented silicon steel plate has a thickness of 0.3 to 0.35 mm and is quite rigid by itself, so simple taping is sufficient. Conventional wound cores like this are made of
A strip-shaped electrical steel sheet manufactured by rolling with a thickness of 0.3 to 0.35 mm containing 3.5% or less silicon was used. In response to this, recently, electrical steel sheets manufactured by the melt ultra-quenching method have been developed. The electrical steel sheets produced by the melt ultra-quenching method include those with a polar grain structure in which 6% silicon is impregnated into iron, and those with a polar grain structure in which iron contains 6% silicon;
There are two types: those containing metalloid elements (B, C, Si, P, etc.) and those that are amorphous. Both exhibit excellent magnetic properties with significantly lower iron loss and excitation current than conventional silicon steel sheets, but because they are manufactured using an ultra-quenching method, the thickness of the electrical steel sheets is less than 150 μm and the width is 5 to 10 cm. This is the limit. For this reason, when these electromagnetic steel sheets are used in small transformers or instrument current transformers, they are extremely thin, must be wound in several strips horizontally in order to obtain the required width, and the surface It is necessary to develop a new manufacturing method, taking into account the unevenness, poor space factor, and the tendency for the shape to collapse. That is, it is difficult to manufacture using the conventional wound core structure.

Therefore, the present invention provides a structure in which a non-cut wound core can be rationally manufactured using an electrical steel sheet manufactured by the melt ultra-quenching method, which has very excellent magnetic properties but is difficult to use in terms of material shape. The purpose is to

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a non-cut wound core according to the present invention will be described in detail below with reference to the drawings.
Figure 3 shows the first example of the overall shape as a conventional example.
A front view of the outline of the same rectangular shape as the one in the figure,
FIG. 4 is a sectional view of the BB section. The wound core indicated by the overall code 11 has four blocks of cores 3-1, 3.
-2, 3-3, and 3-4, and the overall cross-sectional shape is inscribed in a circle as shown in FIG. 4, as in the conventional case. The specific manufacturing method is as follows.
That is, although not shown, the reinforcing material 4-1 made of magnetic material is wound around a core having predetermined dimensions similar to the conventional method. The reinforcing material may be, for example, a conventional grain-oriented silicon steel plate wound several times. Next, an electromagnetic steel plate (hereinafter simply referred to as electromagnetic steel plate) having the same width as the reinforcing material made by the ultra-quenching method is wound a predetermined number of times to form the first block 3.
- form 1. A reinforcing material 4-2 made of magnetic material having a wider width than before is wound on top of it. This also uses, for example, a grain-oriented silicon steel plate, as described above. The same applies to the reinforcing material below. On top of that, two more sets of electromagnetic steel plates are arranged and wound a predetermined number of times to form the second and third blocks 3.
-2 and 3-3 are formed, and a reinforcing material 4-3 with a width equal to the sum of the widths of the two blocks is wrapped thereon to prevent the shape from collapsing. Further, an electromagnetic steel plate is wound on top of it to form a fourth block 3-4, a reinforcing material 4-4 is wound on top of it, and the end of the winding is fixed by spot welding or the like, and the core winding work is completed. The wound iron core configured in this way is immersed in a resin bath together with the winding core,
Impregnating the resin into the reinforcement material and the gaps between the electromagnetic steel sheets,
The resin is then placed in a drying oven to harden, and the core is removed to complete a non-cut wound core. In some cases, the shape of the winding core is initially circular instead of rectangular as in the above example. A front view of the outer appearance of the wound core in that case is shown in FIG. 5, and a cross-sectional view of the CC section is shown in FIG. Other than the overall shape of the front view, this embodiment is completely the same as the previous embodiment, so the same parts are given the same reference numerals and the explanation thereof will be omitted. In this way, the core is first made in a circular shape, and when the core winding is completed, the circular core is removed, and a rectangular mold of a predetermined shape with the same circumference is press-fitted into the core to form a rectangular core.The core is impregnated with resin and hardened. After removing the mold, a rectangular non-cut wound core can be made. The cross-sectional shape can be arbitrary. Another embodiment is shown in FIG. This is an example in which multiple stages are provided to improve the space factor within the circular coil. The one shown in FIG. 8 has a rectangular shape and is often used in instrument current transformers. The manufacturing method for both is the same, so the explanation will be omitted. In both figures, reference numeral 3 indicates an electromagnetic steel plate, and reference numeral 4 indicates a magnetic reinforcing material.

According to the present invention described above, by using a reinforcing material having sufficient strength at each end of the block,
By winding an extremely thin electrical steel sheet with a thickness of 150 μm in any number of strips, a non-cut wound core with any cross-sectional shape can be manufactured. The overall shape can also be adjusted arbitrarily. Furthermore, by impregnating and curing the resin, the rigidity of the iron core can be increased, so that the winding wire can be wound directly on the iron core. Therefore, any desired overall shape or cross-sectional shape can be easily manufactured, and when used in a transformer or current transformer, an energy-saving device with low excitation current and significantly low no-load loss can be obtained.

[Brief explanation of the drawing]

FIG. 1 is an external front view of an example of a conventional non-cut type wound core, FIG. 2 is a cross-sectional view taken along line A-A, and FIG. 3 is an external front view of an example of a non-cut type wound core according to the present invention. Figure 4 is a sectional view of the BB section, and the fifth
The figure is an external front view of another embodiment, and FIG. 6 is its C.
-C section sectional view, Figure 7 is a sectional view of the third embodiment,
FIG. 8 is a sectional view of the fourth embodiment. 1; Conventional wound core, 2-1, 2-2, 2-3;
Iron core block made of conventional grain-oriented silicon steel plate, 3.
3-1, 3-2, 3-3, 3-4; Iron core block made of electrical steel sheet according to the present invention, 4, 4-1, 4-
2,4-3,4-4; Magnetic reinforcing material according to the present invention,
11; Wound core according to the present invention.

Claims (1)

[Claims] 1. An iron core block is formed by winding extremely thin electromagnetic steel sheets in one or more rows and arranging magnetic reinforcing materials on both sides in the lamination direction, and forming a plurality of pieces of any width and thickness. A non-cut wound core made by combining iron core blocks to form an arbitrary cross-sectional shape, and then impregnating and hardening the entire core with resin. 2. Claim No. 2 in which the electrical steel sheet is an amorphous electrical steel sheet made of metallic elements (Fe, Co, Ni, etc.) and semimetallic elements (B, C, Si, P, etc.) manufactured by a melt ultra-quenching method. The uncut wound core described in item 1. 3. The non-cut wound core according to claim 1, wherein the electrical steel sheet has a polar grain structure manufactured by a melt ultra-quenching method containing iron and 6% or less silicon.