JP2000171167A - Metal crucible with good conductivity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate metal fatigue and prevent noise from increasing in advance by restricting the movement toward a direction for spreading a segment due to the electromagnetic vibration of the segment without forming one turn. SOLUTION: A fixing tool 14 made of an insulator with a larger protuberance than a shaft is provided at both end parts of the shaft, a recess where the protuberance of the fixing tool 14 at a position inside the end part of a segment 12 and one portion of the shaft are engaged is provided at the upper portion of the segment 12, and the fixing tool 14 is engaged to the recessed part of the segment 12 while spanning the adjacent segments 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a good conductive metal crucible having a plurality of radial slits in a circumferential direction, and a good conductive metal segment divided by the slits.

[0002]

2. Description of the Related Art When a high-frequency current is supplied to an induction coil provided on the outer peripheral side of a crucible made of a good conductive metal having a radial slit provided in a circumferential direction and having segments divided by the slit, a magnetic flux generated by the induction coil is reduced. The part penetrates into the crucible through the slit, interlinks with the melting material in the good conductive metal crucible and induces and melts the melting material by induction heating, and also interlinks with the segments to induce eddy currents in the segments. I do. Since the eddy current of this segment and the eddy current induced in the melted material are opposite to each other on opposite surfaces, a repulsive force is generated. Since this repulsive force becomes a force for floating the molten metal, eddy currents are necessary for the segments, but the eddy currents are opposite to each other on opposing surfaces between adjacent segments, so that a repulsive force is generated, and an induction coil is generated. The segment is vibrated at a frequency twice the frequency of the high-frequency current supplied to the segment. In order to prevent a mechanical adverse effect due to this vibration, in a conventional good conductive metal crucible, a slit is not provided up to the upper part of the good conductive metal crucible as shown in FIGS. It is common to use a crucible made.

FIG. 5 is a longitudinal sectional view of a conventional flotation melting apparatus, FIG. 6 is a schematic view of a good conductive metal crucible of FIG. 5, and FIG. 7 is a cross sectional view of the good conductive metal crucible of FIG. FIG. 8 shows FIG.
FIG. 1 is a partial cross-sectional view of the crucible made of a good conductive metal of FIG. 5 to 8, reference numeral 1 denotes a crucible made of a good conductive metal having radial slits 2 at substantially equal intervals in a circumferential direction, 3 denotes a flow path of cooling water for cooling the crucible 1 made of a good water, and 4 denotes a good conductive material. An induction coil for inductively heating and melting the molten material charged into the metal crucible 1, 5 is a molten metal in which the molten material charged in the good conductive metal crucible 1 is melted, and 6 is a molten metal that is melted. A tray of the upper molten metal 5 cooled and solidified at the bottom of the good conductive metal crucible 1, and 7 denotes a segment divided by a slit 2 pierced radially in the body of the good conductive metal crucible 1.

[0005] In FIGS. 5 to 8, a crucible 1 made of a good conductive metal is formed as a bottomed crucible provided with a radially elongated slit 2 in a body of a cylindrical body, and a segment 7 divided by the slit 2. A cooling water passage 3 is provided substantially at the center of the crucible 1 through the upper and lower segments between the segments 7 to the lower cooling water inlet / outlet.
To cool down. This good conductive metal crucible 1
An induction coil 4 is wound on the outer peripheral side of, and is connected to an AC power source (not shown).

In the above configuration, a part of the magnetic flux generated by the induction coil 4 penetrates into the crucible 1 made of a good conductive metal and the slit 2 of the crucible 1 made of a good conductive metal and enters the crucible 1 made of a good conductive metal. In addition to inducing eddy current in the molten material by interlinking with the molten material charged in the metal crucible 1, eddy current is also induced in the segment 7 of the good conductive metal crucible 1 mainly divided by the slit 2. I do. The eddy current induced in the melting material generates Joule heat between the eddy current and the electric resistance of the melting material to heat and melt the melting material. This segment 7
The eddy current induced in the material and the eddy current induced in the molten material have opposite directions on opposite surfaces, so that repulsive forces are generated. The crucible 1 made of a good conductive metal is fixed, so that the molten material melts. The molten metal 5 floats away from the crucible 1 made of a good conductive metal. Since the magnetic flux from the induction coil 4 is small at the bottom of the molten metal, no repulsive force for floating the molten metal 5 is generated, and the bottom of the molten metal 5 is cooled by the bottom of the crucible 1 made of a good conductive metal and solidified by cooling. It is a saucer 6 for the molten metal 5 (called a skull because its shape resembles a skeleton), and the molten metal 5 is melted in a non-contact manner on the side wall by the repulsive force from the crucible 1 made of a good conductive metal. Since it is in contact with the tray 6, it is melted without directly contacting the crucible 1 made of a good conductive metal. Since the eddy current induced in the segment 7 heats the segment 7, cooling water is passed through the water passage 3 to cool the good conductive metal crucible 1 so as not to overheat.

As a conventional example other than the above, although not shown, in a crucible made of a good conductive metal which is formed by laminating segments in the circumferential direction via slits and in which adjacent segments are not integrally formed. In order to prevent an adverse effect due to electromagnetic vibration between segments, a wedge of an insulator is fitted between the segments.

[0007]

However, in the conventional structure, in a crucible made of a good conductive metal having an integrated upper portion, the portion shields a magnetic flux that tends to enter the crucible from the slit to form one turn. The eddy current induced in the molten metal in the crucible is reduced as compared with the case where there is no one turn at the top for the same induction coil current, and the electric efficiency is reduced accordingly. In addition, the method of restraining the electromagnetic vibration of the segment with a wedge without forming one turn on the upper part cannot be restrained in the direction in which the slit spreads, so long-term use causes distortion in the direction in which the slit spreads, and metal fatigue is constantly added. As a result, the strength is reduced and noise is increased. In addition, in the case of skull melting or the like, when the molten metal intrudes into the gap generated by the distortion of the slit, the molten metal that has entered the spread of the slit in the skull portion solidifies and becomes a wedge, making it difficult to remove the skull.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problem. It is an object of the present invention to restrain the movement of the segment in the direction in which the segment spreads due to electromagnetic vibration without forming one turn, thereby eliminating metal fatigue. Along with
An object of the present invention is to provide a crucible made of a good conductive metal, which can prevent an increase in noise.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the invention according to claim 1 is based on a good conductive material having a plurality of radial slits in the circumferential direction, and a good conductive metal segment divided by the slits. In a metal crucible, an insulating fixture having a bulge larger than the shaft is provided at both ends of the shaft, and a bulge portion of the fixture at a position inside the end of the segment at the top of the segment; A recess in which a part of the shaft is fitted is provided, and a recess in which the shaft portion of the fixture is fitted above the insulator attached between the segments, and the fixture is straddled between adjacent segments, and And fitting into the concave portion of the insulator between the segments.

According to a second aspect of the present invention, there is provided a good conductive metal crucible having a plurality of radial slits in the circumferential direction, and a good conductive metal segment divided by the slits. A fixture made of an insulator having a bulge larger than the shaft is provided, and a bulge portion of the fixture at a position inside the end of the segment and a recess into which a part of the shaft is fitted are provided at the lower part of the segment. Providing a recess at the lower part of the insulator to be mounted between the segments, into which the shaft of the fixture is fitted, and fitting the fixture over the adjacent segments to fit the segments and the recesses of the insulator between the segments. It is characterized in that it is inserted.

Further, as in the third aspect of the present invention, in the crucible made of a good conductive metal according to the first aspect, a fixture made of an insulator having a bulge larger than the shaft is provided at both ends of the shaft. At the lower part of the segment, a bulge portion of the fixture at a position inside the end of the segment and a recess into which a part of the shaft is fitted, and a portion of the shaft of the fixture at a lower portion of the insulator attached between the segments. The fixing tool can be fitted into the recesses of the segments and the insulator between the segments by straddling the adjacent segments.

According to the above construction, the bulges at both ends of the shaft of the fixture and the shaft are fitted to the upper and lower portions or both of the upper and lower portions of the segment, and the force acting on the adjacent segments in the expanding and contracting directions due to electromagnetic vibration. , It is possible to eliminate metal fatigue due to the electromagnetic vibration and to prevent an increase in noise.

Further, as shown in the electromagnetic analysis results using the model of the crucible made of a good conductive metal shown in Table 1, a crucible made of a good conductive metal having one turn formed and a crucible made of a good conductive metal not having one turn formed Then, when the same current of 1000 A is supplied to both induction coils, the loss (melting energy) generated in the molten metal is smaller in the crucible made of a good conductive metal in which one turn is formed. By forming such that one turn is not formed at the upper and lower ends of the crucible made of a good conductive metal, it is possible to prevent a decrease in the electrical efficiency of the crucible made of a good conductive metal.

[0014]

[Table 1]

1 shows the structure of a main part of an embodiment of the present invention. FIG. 1A is a sectional view of a crucible made of a good conductive metal, and FIG. FIG. In FIG. 1, members denoted by the same reference numerals as those of the conventional example have approximately the same functions, and therefore description thereof will be omitted. In FIG. 1, reference numerals 8 denote radial slits 9 at substantially equal intervals in the circumferential direction, and an outlet 1 for molten metal 11 at the bottom.
A crucible made of a good conductive metal having 3, 10 is an induction coil for inductively heating and melting the molten material put in the crucible 8 made of a good conductive metal, and 11 is a melting material put in the crucible 8 made of a good conductive metal. The molten metal 12 is a segment divided by a slit 9 radially perforated in the body of the crucible 8 made of a good conductive metal, and 14 is formed in a dumbbell shape by providing bulges at both ends of the shaft. A fixing tool 15 fitted to one of the upper and lower portions of the segment or the upper and lower portions of the segment, and 15 denotes an AC power supply for supplying a high-frequency current to the induction coil 10.

In FIG. 1, a crucible 8 made of a good conductive metal is used.
Is formed into a dumbbell shape by providing bulges at both ends of the shaft,
A fixture 14 that suppresses electromagnetic vibration acting in the direction of expansion and contraction between the segments 12 is fitted into one of the upper and lower portions of the segments 12 or a recess provided in both the upper and lower portions across the adjacent segments 12. The crucible 8 made of a good conductive metal is integrated. An induction coil 10 is wound around the outer periphery of the good conductive metal crucible 8.
Is connected to an AC power supply 15.

In the above configuration, a part of the magnetic flux generated by the induction coil 10 penetrates into the good conductive metal crucible 8 through the good conductive metal crucible 8 and the slits 9 of the good conductive metal crucible 8, and An eddy current is induced in the molten material by interlinking with the molten material charged in the metal crucible 8, and an eddy current is also induced in the segment 12 of the good conductive metal crucible 8 mainly divided by the slits 9. I do. The eddy current induced in the melting material generates Joule heat between the eddy current and the electric resistance of the melting material to heat and melt the melting material. The eddy current induced in the segment 12 and the eddy current induced in the molten material have opposite directions on opposite surfaces, so that repulsive forces are generated to float the molten metal 11.

The electromagnetic vibration generated by the eddy current of the segment 12 is suppressed by the fixture 14 fitted to one of the upper and lower portions of the segment 12, or both upper and lower portions. The slit 9 is provided over the entire length of the crucible 8 made of a good conductive metal in the vertical direction. The induction coil 4 is also wound up to the outer peripheral side of the bottom of the crucible 8 made of a good conductive metal. Are the segments 12 of the crucible 8 made of a good conductive metal.
The repulsive force from the eddy current and the current of the induction coil 10 wound around the outer periphery of the good conductive metal crucible 8 is received over the side wall and the bottom of the molten metal 11, and the repulsive force moves away from the good conductive metal crucible 8. Is given a sufficient pinch force, and the molten metal 11 completely floats.

Since the eddy current induced in the segment 12 heats the segment 12 itself, cooling is performed by passing cooling water through a water passage in the segment 12 (not shown) so that the segment 12 is not overheated. The molten metal 11 melted by the good conductive metal crucible 8 is discharged from an outlet 13 provided at the bottom of the good conductive metal crucible 8.

FIG. 2 is a block diagram showing one embodiment of the present invention. In FIG. 2, 8A has radial slits 9A at substantially equal intervals in the circumferential direction, and a good conductive metal crucible for melting the side surface of the molten metal 11 in a non-contact manner, and 10A was put into the good conductive metal crucible 8. An induction coil for inductively heating and melting the molten material; 12A, segments divided by slits 9A provided radially on the body of a good conductive metal crucible 8A;
Is a dumbbell-shaped bulge provided at both ends of the shaft, and is fixed to one of the upper and lower portions of the segment or both upper and lower portions across the adjacent segments. 1 shows an AC power supply for supplying power.

FIG. 2 is different from FIG.
Is that a fixing tool is applied to a crucible made of a good conductive metal which is brought into contact with the bottom of a molten metal to be melted instead of being applied to a completely floating type crucible made of a good conductive metal.

FIG. 3 is a structural diagram of a crucible made of a good conductive metal shown in FIG.
And FIG. 4 in which a part of the good conductive metal crucible of FIG. 3 is developed.
As shown in FIG. 2, the lower portion of the segment 12B divided by the slit 9B instead of the good conductive metal crucible 8A of FIG. 2 is projected to the outer peripheral side so as to have an L-shaped cross section, and is screwed to the disc-shaped bottom. Alternatively, the fixture 14 may be fitted to the upper surface of the crucible 8B made of a good conductive metal for melting a skull in which the side wall and the bottom surface of the molten metal solidify to form the skull 16.

[0022]

According to the present invention, since the fixing member made of an insulating material is fitted between the segments forming the crucible made of a good conductive metal to suppress the movement of the segments in the opening direction, the variation of the slit width is reduced. This eliminates the metal fatigue of the segment due to electromagnetic vibration, and the fixture is made of an insulating material, so that there is no portion that forms one turn above and below the crucible made of a good conductive metal, which has the effect of preventing a decrease in electrical efficiency. .

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a main part of an embodiment of the present invention.

FIG. 2 is a configuration diagram of one embodiment of the present invention.

FIG. 3 is a configuration diagram of another embodiment of the present invention.

FIG. 4 is an expanded view of a part of the good conductive metal crucible of FIG.

FIG. 5 is a longitudinal sectional view of a conventional flotation melting apparatus.

6 is a schematic view of the crucible made of a good conductive metal of FIG.

FIG. 7 is a cross-sectional view of the crucible made of a good conductive metal of FIG. 5;

FIG. 8 is a partial cross-sectional view in which the middle of the inner and outer peripheries of the good conductive metal crucible of FIG.

[Explanation of symbols]

 8, 8A, 8B Crucible made of good conductive metal 9, 9A, 9B Slit 10, 10A, 10B Induction coil 11 Melt 12, 12A, 12B Segment 13 Outflow port 14 Fixture 15 AC power supply

Claims (3)

[Claims] 1. A crucible made of a good conductive metal having a plurality of radial slits in a circumferential direction and segments made of a good conductive metal separated by the slits, wherein both ends of the shaft have bulges larger than the shaft. A fixture made of a product is provided, and a bulge portion of the fixture at a position inside the end of the segment and a recess into which a part of the shaft is fitted are provided at an upper portion of the segment, and an insulator attached between the segments is provided. A recess in which the shaft portion of the fixing tool is fitted at the upper part of the fixing tool, straddling the fixing tool between adjacent segments,
A crucible made of a good conductive metal, wherein said crucible is fitted in a recess of an insulator between segments. 2. A crucible made of a good conductive metal having a plurality of radial slits in a circumferential direction and segments of a good conductive metal divided by the slits, wherein both ends of the shaft have insulation bulges larger than the shaft. A fixture made of a product is provided, and a bulge portion of the fixture at a position inside the end of the segment and a recess into which a part of the shaft is fitted are provided at a lower portion of the segment, and an insulator mounted between the segments is provided. At the bottom of the is provided a recess in which the part of the shaft of the fixture is fitted, and straddle the fixture between adjacent segments,
A crucible made of a good conductive metal, wherein said crucible is fitted in a recess of an insulator between segments. 3. The crucible made of a good conductive metal according to claim 1, wherein a fixing member made of an insulating material having a bulge larger than the shaft is provided at both ends of the shaft, and a lower portion of the segment is inside the end of the segment. A bulge portion of the fixing tool at a position and a recess into which a part of the shaft is fitted are provided,
A recess is provided in the lower part of the insulator to be mounted between the segments, into which the shaft portion of the fixture is fitted, and the fixture is straddled between adjacent segments, and fitted into the segments and the recess of the insulator between the segments. A crucible made of a good conductive metal, characterized in that: