JP2562877Y2 - Levitation coil - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a levitation used in an electromagnetic levitation continuous casting method in which a molten metal is floated by using a moving (alternating) magnetic field generated by a multi-phase current and a multi-stage coil, and the molten metal is injected into a mold. For coils.

[0002]

2. Description of the Related Art As a coil used in a conventional electromagnetic levitation continuous casting method, a unit coil 1 wound as shown in FIG. 3 is stacked in multiple stages as shown in FIG. 4A. From this figure, the spirally wound hollow conductor 2 of the unit coil 1 has four turns per layer, and the ends 2a and 2b at the beginning and end of the winding are located in the same direction.

For this reason, in the levitation coil 3 configured by stacking the unit coils 1 in multiple stages as shown in FIG. 4A, as shown in FIG. The terminal 2a at the beginning of winding and the terminal 2b at the end of winding almost overlap each other. Each unit coil 1 is provided with a hollow conductor 3 in each phase of a three-phase power supply (not shown).
a, 3b, 3c, and the unit coils 1 are also connected by hollow conductors 4a, 4b, so that a moving magnetic field is generated in the levitation coil 3.

[0004]

In the conventional levitation coil 3, since the terminal 2a at the beginning of winding and the terminal 2b at the end of winding of the adjacent out-of-phase unit coil as described above almost overlap with each other, 1 is weak on the terminal side and strong on the opposite side, resulting in inhomogeneity in the magnetic field, which causes casting instability and defects in the ingot. When the actual measurement of the magnetic field was performed, it was 0.20 T on the terminal side and 0.18 T on the opposite side.

A unique levitation mark is formed on the surface of the cast rod by the magnetic levitation continuous casting method. The levitation mark 5 is shown in FIG. As described above, the casting rod 6 is greatly inclined with respect to the axis thereof, which also causes a defect of the casting rod 6. Incidentally, it is desirable that the levitation mark 5 has a shape substantially perpendicular to the axis as shown in FIG.

The present invention has been made based on the above circumstances, and provides a levitation coil capable of obtaining a uniform magnetic field and forming a levitation mark substantially perpendicular to the casting rod axis.

[0007]

The levitation coil of the present invention comprises a unit coil having a winding start terminal and a winding end terminal extracted at an angle of 120 ° with respect to the center of winding.
It is characterized in that adjacent unit coils are shifted by 120 ° and superposed in multiple stages.

[0008]

In the levitation coil of the present invention having the above structure, the winding start terminal and the winding end terminal of adjacent unit coils, that is, unit coils of different phases do not overlap with each other.
A uniform magnetic field can be obtained, and there is no possibility of causing various inconveniences due to the non-uniform magnetic field.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic plan view of a unit coil according to an embodiment of the present invention, FIG. 2A is a schematic plan view of the embodiment in which the unit coils are stacked in multiple stages, and FIG. It is a schematic front view. In FIG. 1, a unit coil 11 used in the present invention is formed by winding a hollow conductor 12 into four layers, and its winding start terminal 12a and winding end terminal 1a.
2b is 120 with respect to the center of the winding of the unit coil 11.
° is extracted at an angle.

When the six unit coils 11 are stacked to form the levitation coil 13, the terminals 12a and 12b of the unit coils 11 adjacent in the axial direction are most clearly shown in FIG. 2A. The adjacent unit coils 11 are shifted by 120 ° in the circumferential direction so as not to overlap. Note that the six-phase order and terminal connection mode for each unit coil are the same as those in the conventional levitation coil shown in FIG.

In the embodiment of the present invention having the above structure, the terminals 12a and 12b protrude in three directions at intervals of 120 °, so that the winding start terminals 12a, 12a,
There is no possibility that the magnetic field becomes non-uniform due to overlapping with the end-of-winding terminal 12b. In addition, since the magnetic field is not biased as described above, the levitation mark 5 that is substantially perpendicular to the casting rod axis is formed on the surface of the casting rod 6 as shown in FIG. 5A.

[0012]

As described above, the levitation coil according to the present invention can generate a uniform magnetic field, so that stable continuous casting can be performed, and the shape of the levitation mark is aligned with the casting rod axis. Since it is substantially vertical, it is possible to obtain a high quality ingot without defects caused by the levitation mark. Therefore, the continuous casting method can be performed with high productivity.

[Brief description of the drawings]

FIG. 1 is a plan view of a unit coil according to an embodiment of the present invention.

FIG. 2 is a schematic front view of the levitation multi-stage coil according to the embodiment of the present invention.

FIG. 3 is a schematic plan view of a conventional unit coil.

FIG. 4A is a schematic front view of a conventional levitation coil configured by stacking the unit coils, and FIG. 4B is a schematic plan view thereof.

FIG. 5 (A) is a schematic front view showing a levitation mark of a cast rod obtained by a continuous casting method performed using the levitation coil of the present invention, and (B) is a conventional levitation coil. FIG. 4 is a schematic front view showing a levitation mark in a casting rod obtained by a continuous casting method performed using the method.

[Explanation of symbols]

1,11 unit coil, 2,12 hollow conductor, 2a, 1
2a: winding start terminal, 2b, 12b: winding end terminal, 3, 1
3. Levitation coil.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Mikio Tanaka 2-1, 1-1 Sakae Oda, Kawasaki-ku, Kawasaki City, Kanagawa Prefecture Inside Showa Electric Wire & Cable Co., Ltd.

Claims (1)

(57) [Scope of request for utility model registration] A unit coil having a winding start terminal and a winding end terminal extracted at an angle of 120 ° with respect to the center of winding is superposed in a multistage manner by shifting adjacent unit coils by 120 °. Features a levitation coil.