JPS63242443A - Casting apparatus in electromagnetic field - Google Patents

Abstract

PURPOSE:To improve shape and quality of a cast ingot obtd. and to effectively obtain stability by controlling cooling rate at peripheral side face part of solidified position of the cast ingot formed at lower part of molten metal column, which is held to rectangular shape in electromagnetic field, relatively to the four corner part. CONSTITUTION:Molten metal 14 of Al alloy, etc., is supplied on a bottom base 10 through a nozzle 12. The peripheral face at side part of the molten metal 14 under molten state is held by the electromagnetic pressure through rectangular shaped coil 16 arranged around the bottom base 10, to form the rectangular shaped molten metal column 18. To the peripheral face at side part of the solidified position 22 of the cast ingot formed at lower part of the molten metal column 18, by injecting cooling water from discharging hole 24 of cooling water jacket 20, it is cooled, to continuously obtain the cast ingot. In the above electromagnetic field casting apparatus, water shelting plates 28 are arranged at four corner of shelter screen 26 controlling the magnetic field of the center part of each side and the four corner parts in the peripheral side face part of the above solidified position 22 of the cast ingot are relatively controlled. By this method, the holding height of the molten metal column 18 is uniformized over the whole round and the shape and quality of the cast ingot is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an electromagnetic field casting device, and particularly to an electromagnetic field casting device that can effectively stabilize the shape of the four corners of an ingot when producing a rectangular columnar ingot. It is related to the device.

(Prior art and its problems) As is well known, the electromagnetic field casting method, which is a type of continuous casting method (including semi-continuous casting method; the same applies hereinafter) for metals, especially aluminum or its alloys, is a method for casting metals, especially aluminum or its alloys. The circumferential side of the molten metal supplied onto a gradually descending base placed in the generated alternating magnetic field is held by electromagnetic pressure to form a molten metal column with a shape corresponding to the coil shape, and the molten metal is By jetting cooling water against the side circumferential surface of the solidified ingot formed at the bottom of the column, the molten metal column is continuously cooled and solidified through the solidified ingot. In recent years, there have been great expectations for its adoption, as it is a method for producing ingots in a conventional manner, and it is possible to obtain ingots with a smooth ingot surface and excellent Mi texture.

By the way, in such an electromagnetic field casting method, the molten metal column is shaped into a predetermined shape by the electromagnetic repulsive force (electromagnetic pressure) that acts between the current supplied to the coil and the induced current generated in the molten metal column. Since it is something that allows us to maintain
In order to hold the circumferential surface of the molten metal column in a constant shape, that is, vertically, it is necessary to balance the static pressure of the molten metal column, in other words, the holding height of the molten metal column, and the distribution of electromagnetic pressure applied to it. It is necessary to maintain it at all times.

However, in such electromagnetic field casting, the jetting of cooling water to the side circumferential surface of the solidified ingot is generally carried out by a cylindrical cooling water jacket disposed around the entire side of the molten metal column. This is especially true for rectangular columnar castings because the cooling water flowing inside the casting is spouted out through openings that are opened diagonally downward and have approximately uniform openings in the circumferential direction. When manufacturing a block, the flow rate of cooling water jetted to the four corners is relatively larger than that at the center of each side, and the cooling area at the four corners is larger than the center, resulting in improved cooling efficiency. Because of the height, the solidified shells at the four corners stand up higher than at the center, and accordingly, the height of the molten metal column at the four corners becomes lower than at the center.

As a result, the balance between the hydrostatic pressure of the molten metal column at the four corners and the electromagnetic pressure applied thereto is lost, making it extremely difficult to maintain the molten metal column in a constant shape, resulting in unevenness in the ingot. Therefore, in the conventional production of rectangular columnar ingots, the shape and quality of the obtained ingots are not good, and the operation is unstable. It had inherent problems.

(Solution Means) Here, the present invention has been made against the background of the above-mentioned circumstances, and its feature is that a vertically formed molten metal column is generated by a predetermined coil means. While being held in a rectangular shape by the applied electromagnetic field,
By jetting cooling water to the side circumferential surface of a solidified ingot portion formed at the bottom of the molten metal column, the molten metal column is continuously cooled and solidified via the solidified ingot portion,
In the above-mentioned electromagnetic field casting apparatus that continuously produces rectangular columnar ingots, the amount of cooling by the cooling water at the center of each side and the four corners of the peripheral side of the solidified ingot is compared. The reason is that a control means is provided to control the process.

(Examples) Hereinafter, in order to clarify the present invention more specifically, examples of the present invention will be described in detail with reference to the drawings.

First, FIG. 1 is a schematic explanatory diagram showing an example of an electromagnetic field casting apparatus having a structure according to the present invention.

In this figure, reference numeral 10 denotes a base, onto which a molten metal 14 such as aluminum or its alloy is supplied through a nozzle 12 disposed above the base. Further, a rectangular frame-shaped coil 16 is arranged around the base 10, and the electromagnetic pressure generated by the coil 16 causes the side circumferential surface of the molten metal 14, which is still in a molten state, to be is held until it solidifies, so that a molten metal column 18 having a shape similar to the coil shape (rectangular cross-sectional shape) is formed on the base 10.

Although not shown, the nozzle 12 is provided with a suitable level control mechanism such as a float device, so that the scene on the base 10 can be maintained at a constant level.

Further, a cooling water jacket 20 is disposed around the entire periphery of the molten metal column 18 formed on the base 10. This cooling water jacket 20 has a cylindrical cross section and is formed in the shape of a rectangular frame as a whole, and has a discharge port 24 that opens obliquely downward toward the center on the inner side of the lower surface thereof in the circumferential direction. It is placed around the circumference. As is well known, the cooling water flowing through the molten metal column 18 is directed to the side peripheral surface (outer surface) of the solidified ingot region 22 formed at the bottom of the molten metal column 18 through the discharge port 24. On the other hand, the cooling water is jetted out at a predetermined discharge angle over the entire circumferential surface, and by this jetting of cooling water, the molten metal column 18 is continuously cooled through the solidified ingot part 22. , is solidified, and the produced ingot 22 is continuously pulled downward as the base 10 descends, so that the desired ingot can be continuously obtained.

As shown in FIG. 2, the cooling water jacket 20 in this embodiment is formed with a rectangular cylindrical cross section, and is arranged above the coil 16 independently of the coil 16. At the same time, its inner wall portion is covered with a shielding screen 2.
6, and as is well known, the electromagnetic pressure applied to the molten metal column 18 by the coil 16 is reduced upwardly in proportion to the static liquid pressure of the molten metal column 18. , the circumferential side surface of the molten metal column 18 is held vertically.

Here, thin plate-shaped water shielding plates 28 are integrally attached to the shielding screen 26 constituting the inner wall portion of the cooling water jacket 20 at its four corners. As shown in FIGS. 3 and 4, this water shielding plate 28 extends vertically below the shielding screen 26 and is provided on a jet flow path of cooling water spouted through the outlet 24 at a predetermined level. The discharge port 2 is fixedly installed with a width.
The direction in which the cooling water is ejected from the cooling water is regulated by the water shielding plate 28, and is allowed to flow downward in a vertical direction.

That is, the produced ingot 2 passes through the cooling water jacket 20.
Since the outlet 24 is formed with a substantially constant opening amount over the entire circumference, especially at the four corners of the produced ingot 22, the direction of the injection of cooling water is different from each other. Since it converges at the corner, the amount of water sprayed per unit area (the amount of water sprayed) will be larger than that at the center of each side.
By controlling the jetting direction, the amount of cooling water jetted to each corner of the produced ingot 22, in other words, the amount of cooling can be effectively reduced.

Note that various materials can be used for the water shielding plate 28, such as metals such as aluminum alloy and stainless steel, ceramics, resins, and carbon paper. Rigidity against the water pressure of the cooling water is required, and especially when aluminum alloy is used, it is necessary to avoid adverse effects on the electromagnetic field generated by the coil 16. It is desirable to use a thin material (for example, 1/10 or less), for example, an aluminum foil with a wall thickness of about 50 μm to 1 Tsuru.

Therefore, in the electromagnetic field casting apparatus having the structure as described above, the water shield plate 28 at the corner of the cooling water jacket 20
By making the amount of cooling water sprayed directly onto the four corners of the produced ingot 22 equal to or even smaller than that at the center of each side, the amount of cooling at each corner is controlled. As a result, it is possible to effectively prevent or suppress the rise of a solidified shell due to the progress of partial solidification at the four corners of the molten metal column 18, as described above.

Therefore, since the holding height of the molten metal column 18 on the side peripheral surface can be made approximately equal over the entire circumference, a good balance between the hydrostatic pressure and the electromagnetic pressure can be maintained. Therefore, the molten metal column 18 can be well maintained in a certain shape, and the shape and quality of the obtained ingot can be improved and stabilized, and furthermore, the casting operation can be stabilized very effectively. This means that it can be achieved.

Furthermore, by using such an electromagnetic field casting apparatus, the shape of the ingot can be effectively stabilized and the occurrence of melt leakage can be effectively prevented, so that the yield can be improved.
This means that manufacturing costs can be advantageously reduced.

Furthermore, in the four corners of the molten metal column 18, the radius (curvature) becomes larger as the upper part increases due to the relationship with surface tension, hydrostatic pressure, etc., but by using such an electromagnetic field casting device, it is possible to Since the solidified shell can be set at the bottom, it is possible to set the radius at the four corners of the obtained ingot to be small.

In addition, in the electromagnetic field casting apparatus in this embodiment, the conventional apparatus is used as is, and the cooling water jacket 1-2 is
For the shielding screen 26 that constitutes the inner circumferential wall of 0,
It is only necessary to fix the water shielding plate 28, and by simple processing, it is possible to provide a device that can effectively produce the above-mentioned effects, and is extremely economical.

Next, FIG. 5 shows another embodiment constructed according to the present invention. In this embodiment, the same members as those in the previous embodiment are denoted by the same reference numerals in the drawings, and detailed explanation thereof will be omitted.

That is, in the electromagnetic field casting apparatus of this embodiment, the shielding plate is movable in the vertical direction along the inside of the four corners of the shielding screen 26 that constitutes the inner circumferential wall of the cooling water jacket 20. 30 are arranged respectively.

The water shielding plate 30 is formed of a thin plate having a curvature that substantially matches the curvature of the inner surface of the corner of the shielding screen 26, and is formed in a substantially fan-shaped shape with a width increasing from the bottom to the top. . It is supported by a support rod 32 attached to its top, and its vertical arrangement position can be changed or set by manually or automatically driving the support rod 32 in the vertical direction. It is now possible to The material of the water shielding plate 30 may be metal such as aluminum alloy or stainless steel, resin,
Ceramics, carbon paper, etc. are preferably used.

Therefore, in the electromagnetic field casting apparatus having such a structure, by changing the arrangement position of the water shielding plate 30, the water shielding plate 30 extends vertically below the shielding screen 26, and the discharge port of the cooling water jacket 20 is opened. The width of the water shielding plate 30 positioned on the jet flow path of the cooling water jetted through the ingot 24 can be changed and set as appropriate. The amount of water can be changed.

That is, in the electromagnetic field casting apparatus of this embodiment, as described above, the amount of cooling water spouted to the four corners of the produced ingot 22 is made smaller than that to the center of each side, so that the molten metal column 18 is It is possible to effectively equalize the molten metal holding height on the entire circumference, and also to adjust the cooling amount between the four corners and the center of each side of the ingot in accordance with casting conditions that change depending on the material of the molten metal, etc. As a result, it can be suitably applied to various casting conditions, and all of the above-mentioned effects can be effectively achieved.

Although the electromagnetic field casting apparatus having the structure according to the present invention has been described in detail above, these are literal examples, and the present invention is not to be interpreted as being limited to such specific examples.

For example, in the above embodiment, cooling water jacket) 2
0 had a separate structure from the coil 16, and a part of it was configured as a shielding screen 26, but the structure of the so-called mold is not limited, and for example,
As is known, it is possible to form the cooling water jacket integrally with the coil, and it is also possible to form the shielding screen separately from the cooling water jacket.

In addition, the water shielding plates 28 and 30 in the above embodiments were formed in a thin plate shape and were arranged in the vertical direction, but slits were provided there, and the amount of water ejected was determined by the opening amount of the slits. Furthermore, with such a water shield plate 28 , 30 , the generated ingot 22 of the cooling water jetted out from the outlet 24 of the cooling water jacket 20 can be controlled.
It is also possible to control the amount of cooling by regulating the direction of the ejection so that the portion in contact with the ink is directed downward.

Furthermore, in the embodiment described above, the amount of cooling at the four corners of the produced ingot 22 was controlled by restricting only the direction in which the cooling water was ejected. For example, by arranging a wedge-shaped opening amount regulating member in the discharge port 24, the amount of cooling water jetted out can be varied in the circumferential direction. It is also possible to control the amount of cooling.

In short, in the present invention, it is only necessary to relatively control the amount of cooling at the four corners and the center of each side of the produced ingot 22. Therefore, as described above, cooling at the four corners is possible. In addition to regulating the direction of water jetting, the amount of cooling is controlled by, for example, changing the opening area of the discharge port 24 in the circumferential direction so that the amount of cooling water jetted at the straight portions is larger than that at the four corners. Of course, it is also possible to do so.

In addition, although not listed, the present invention can be implemented in embodiments with various changes, modifications, improvements, etc. based on the knowledge of those skilled in the art, and such embodiments may be different from the present invention. It goes without saying that any of these are included within the scope of the present invention as long as they do not depart from the spirit of the invention.

(Effects of the Invention) As is clear from the above description, in the electromagnetic field casting apparatus having the structure according to the present invention, cooling is performed on the central part of each side and the four corners of the produced ingot (solidified ingot part). The amount of cooling by water is relatively controlled by regulating the direction and amount of water ejected, and the amount of cooling at the four corners is the same as the amount at the center of each side. Furthermore, by making the amount smaller than that, it is possible to effectively prevent or suppress the rise of a solidified shell due to the progress of partial solidification at the four corners of the molten metal column, thereby preventing the molten metal column from being held on the side circumferential surface. Since the height can be made approximately uniform over the entire circumference, the molten metal column can be well maintained in a constant shape,
As a result, the shape and quality of the ingot obtained can be improved and stabilized, and the casting operation can be stabilized very effectively.

[Brief explanation of the drawing]

FIG. 1 is an explanatory cross-sectional view schematically showing the structure of an electromagnetic casting device as an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a straight portion of a cooling water jacket used in such an electromagnetic casting device. FIG. 3 is an explanatory cross-sectional view of the four corner portions thereof, and FIG. 4 is a perspective view for explaining the four corner portions of the cooling water jacket. Further, FIG. 5 is a perspective view corresponding to FIG. 4, showing a cooling water jacket in an electromagnetic field casting apparatus as another embodiment structured according to the present invention. 14: Molten metal 16: Coil 18: Molten metal column 20: Cooling water jacket 22:
Solidified ingot part 24: Outlet 26: Shielding screen 2a, so: Water shielding plate Applicant
Sumitomo Light Metal Industries, Ltd. Figure 1

Claims (1)

[Claims] While a molten metal column formed in a vertical direction is held in a rectangular shape by an electromagnetic field generated by a predetermined coil means, the side of a solidified ingot portion formed at the bottom of the molten metal column is An electromagnetic field that continuously produces rectangular columnar ingots by jetting cooling water onto the circumferential surface of the solidified ingot to continuously cool and solidify the molten metal column through the solidified ingot part. An electromagnetic field casting apparatus, characterized in that the electromagnetic field casting apparatus is provided with a control means for relatively controlling the amount of cooling by the cooling water between the central part of each side and the four corners of the peripheral side part of the solidified ingot part.