U.S. patent application number 14/825893 was filed with the patent office on 2015-12-03 for molding device for continuous casting equipped with agitator.
The applicant listed for this patent is Kenzo TAKAHASHI. Invention is credited to Kenzo TAKAHASHI.
Application Number | 20150343523 14/825893 |
Document ID | / |
Family ID | 48289578 |
Filed Date | 2015-12-03 |
United States Patent
Application |
20150343523 |
Kind Code |
A1 |
TAKAHASHI; Kenzo |
December 3, 2015 |
MOLDING DEVICE FOR CONTINUOUS CASTING EQUIPPED WITH AGITATOR
Abstract
There is provided a molding device for continuous casting
equipped with an agitator that reduces the amount of generated
heat, is easy to carry out maintenance, is inexpensive, and is easy
to use in practice. The molding device for continuous casting
equipped with an agitator of the invention receives liquid-phase
melt of a conductive material, and a solid-phase cast product is
taken out from the molding device through the cooling of the melt.
The molding device includes a casting mold and an agitator provided
so as to correspond to the casting mold. The casting mold includes
a casting space that includes an inlet and an outlet at a central
portion of a substantially cylindrical side wall, and a magnetic
field generation device receiving chamber that is formed in the
side wall and is positioned outside the casting space. The casting
mold receives the liquid-phase melt from the inlet into the casting
space and discharges the solid-phase cast product from the outlet
through the cooling in the casting space. The agitator includes a
magnetic field generation device having an electrode unit that
includes first and second electrodes supplying current to at least
the liquid-phase melt present in the casting space, and a permanent
magnet that applies a magnetic field to the liquid-phase melt. The
magnetic field generation device is received in the magnetic field
generation device receiving chamber of the casting mold, generates
magnetic lines of force toward a center in a lateral direction,
makes the magnetic lines of force pass through a part of the side
wall of the casting mold and reach the casting space, and applies
lateral magnetic lines of force, which cross the current, to the
melt.
Inventors: |
TAKAHASHI; Kenzo;
(Matsudo-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TAKAHASHI; Kenzo |
Matsudo-shi |
|
JP |
|
|
Family ID: |
48289578 |
Appl. No.: |
14/825893 |
Filed: |
August 13, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14115788 |
Nov 5, 2013 |
|
|
|
PCT/JP2012/052412 |
Feb 2, 2012 |
|
|
|
14825893 |
|
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Current U.S.
Class: |
164/504 |
Current CPC
Class: |
B22D 11/112 20130101;
B22D 11/004 20130101; B22D 11/001 20130101; B22D 11/003 20130101;
B22D 11/115 20130101; B22D 11/041 20130101; B22D 11/055
20130101 |
International
Class: |
B22D 11/115 20060101
B22D011/115; B22D 11/00 20060101 B22D011/00; B22D 11/055 20060101
B22D011/055; B22D 11/112 20060101 B22D011/112 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 10, 2011 |
JP |
2011-246666 |
Claims
1-20. (canceled)
21. A molding device for continuous casting equipped with an
agitator which receives liquid-phase melt of a conductive material
and from which a solid-phase cast product is taken out through the
cooling of the melt, the molding device comprising: a casting mold
which is substantially cylindrical, an inside space of which is a
casting chamber having an inlet and an outlet, a water jacket is
formed in a side wall of the casting mold, the shape of the water
jacket is substantially cylindrical; and an agitator including
first and second electrodes and a permanent magnet, the first
electrode to be electrically connected to the melt in the inlet
side and the second electrode to be electrically connected to the
cast product so that an electric current may flow along an
up-and-down direction, the permanent magnet is received in the
water jacket so that the position of the magnet is adjustable in a
up-and-down direction, the shape of the permanent magnet is a frame
shape so that the permanent magnet surrounds the casting chamber,
the inner side of the permanent magnet is magnetized to one of N
and S poles, and the outer side of the permanent magnet is
magnetized to the other of N and S poles, so that the same poles
oppose each other via the casting chamber in order that magnetic
lines of force run substantively horizontally towards the center of
the casting mold to cross the electric current or substantively
horizontally radially run from the center of the casting mold to
cross the electric current.
22. The molding device according to claim 21, wherein the shape of
the casting mold, the water jacket and the permanent magnet is a
circular cylinder shape.
23. The molding device according to claim 21, wherein the shape of
the casting mold, the water jacket and the permanent magnet is a
cylinder shape of which cross-section is rectangular.
24. The molding device according to claim 21, wherein discharge
channels through which cooling water flowing in the water jacket is
jetted to the product are formed in the casting mold.
25. The molding device according to claim 21, wherein the casting
mold has a single structure using a non-conductive material, a
single structure using a conductive material, or a double structure
using a non-conductive material and a conductive material.
26. The molding device according to claim 21, wherein the second
electrode includes a roller at the end thereof, and the roller is
rotated by coming into contact with the outer surface of the cast
product to be taken out.
27. A molding device for continuous casting equipped with an
agitator which receives liquid-phase melt of a conductive material
and from which a solid-phase cast product is taken out through the
cooling of the melt, the molding device comprising: a casting mold
which is substantially cylindrical, an inside space of which is a
casting chamber having an inlet and an outlet, a water jacket is
formed in a side wall of the casting mold, the shape of the water
jacket is substantially cylindrical; and an agitator including
first and second electrodes and a permanent magnet, the first
electrode to be electrically connected to the melt in the inlet
side and the second electrode to be electrically connected to the
cast product so that an electric current may flow along an
up-and-down direction, the permanent magnet is received in the
water jacket so that the position of the magnet is adjustable in a
up-and-down direction, the permanent magnet includes a plurality of
permanent magnet pieces which are received in the water jacket, the
inner side of the each permanent magnet piece is magnetized to one
of N and S poles, and the outer side of the each permanent magnet
piece is magnetized to the other of N and S poles, so that the same
poles oppose each other via the casting chamber in order that
magnetic lines of force run substantively horizontally towards the
center of the casting mold to cross the electric current or
substantively horizontally radially run from the center of the
casting mold to cross the electric current.
28. The molding device according to claim 27, wherein the shape of
the casting mold, the water jacket and the permanent magnet is a
circular cylinder shape.
29. The molding device according to claim 27, wherein the shape of
the casting mold, the water jacket and the permanent magnet is a
cylinder shape of which cross-section is rectangular.
30. The molding device according to claim 27, wherein discharge
channels through which cooling water flowing in the water jacket is
jetted to the product are formed in the casting mold.
31. The molding device according to claim 27, wherein the permanent
magnet pieces are mounted on the inner surface of a support at a
predetermined interval.
32. The molding device according to claim 27, wherein the casting
mold has a single structure using a non-conductive material, a
single structure using a conductive material, or a double structure
using a non-conductive material and a conductive material.
33. The molding device according to claim 27, wherein the second
electrode includes a roller at the end thereof, and the roller is
rotated by coming into contact with the outer surface of the cast
product to be taken out.
34. A molding device for continuous casting equipped with an
agitator which receives liquid-phase melt of a conductive material
and from which a solid-phase cast product is taken out through the
cooling of the melt, the molding device comprising: a casting mold
which is substantially cylindrical, an inside space of which is a
casting chamber having an inlet and an outlet, a water jacket is
formed in a side wall of the casting mold, the water jacket is
formed of a plurality of partial water jackets that are divided and
independent, and each of the partial water jackets is arranged so
as to surround the casting space; and an agitator including first
and second electrodes and a permanent magnet, the first electrode
to be electrically connected to the melt in the inlet side and the
second electrode to be electrically connected to the cast product
so that an electric current may flow along an up-and-down
direction, the permanent magnet includes a plurality of permanent
magnet pieces each of which is received in each of the partial
water jackets, each of the permanent magnet pieces is arranged so
that the position of the each permanent magnet piece is adjustable
in a up-and-down direction in each of the partial water jackets,
the inner side of the each permanent magnet piece is magnetized to
one of N and S poles, and the outer side of the each permanent
magnet piece is magnetized to the other of N and S poles, so that
the same poles oppose each other via the casting chamber in order
that magnetic lines of force run substantively horizontally towards
the center of the casting mold to cross the electric current or
substantively horizontally radially run from the center of the
casting mold to cross the electric current.
35. The molding device according to claim 34, wherein the shape of
the casting mold is a circular cylinder shape.
36. The molding device according to claim 34, wherein the shape of
the casting mold is a cylinder shape of which cross-section is
rectangular.
37. The molding device according to claim 34, wherein discharge
channels through which cooling water flowing in the water jacket is
jetted to the product are formed in the casting mold.
38. The molding device according to claim 34, wherein the casting
mold has a single structure using a non-conductive material, a
single structure using a conductive material, or a double structure
using a non-conductive material and a conductive material.
39. The molding device according to claim 34, wherein the second
electrode includes a roller at the end thereof, and the roller is
rotated by coming into contact with the outer surface of the cast
product to be taken out.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 14/115,788, filed Nov. 5, 2013, which is a 371
of International Patent Application No. PCT/JP2012/052412, filed
Feb. 2, 2012, which claims priority to Japanese Patent Application
No. 2011-246666, filed Nov. 10, 2011. The entire contents of U.S.
patent application Ser. No. 14/115,788 are incorporated herein by
reference.
TECHNICAL FIELD
[0002] The present invention relates to a molding device for
continuous casting, which is equipped with an agitator, of
continuous casting equipment that produces a billet, a slab or the
like made of non-ferrous metal of a conductor (conductive body),
such as Al, Cu, Zn, or an alloy of at least two of them, or an Mg
alloy, or other metal.
BACKGROUND ART
[0003] In the past, a melt agitating method to be described below
has been employed in a casting mold for continuous casting. That
is, for the improvement of the quality of a slab, a billet, or the
like, in a process for solidifying the melt, that is, when the melt
passes through the casting mold, a moving magnetic field, which is
generated from the outside of the casting mold by an
electromagnetic coil, is applied to the melt present in the casting
mold so that agitation occurs in the melt not yet solidified. A
main object of this agitation is to degas the melt and to
uniformize the structure. However, since the electromagnetic coil
is disposed at the position close to high-temperature melt, the
cooling of the electromagnetic coil and troublesome maintenance are
needed and large power consumption is obviously needed. In
addition, the generation of heat from the electromagnetic coil
itself caused by the power consumption cannot be avoided, and this
heat should be removed. For this reason, there are various problems
in that the device itself cannot but become expensive, and the
like.
CITATION LIST
Patent Literature
[0004] Patent Literature 1: JP 9-99344 A
SUMMARY OF INVENTION
Technical Problem
[0005] The invention has been made to solve the above-mentioned
problems, and an object of the invention is to provide a molding
device for continuous casting equipped with an agitator that
reduces the amount of generated heat, is easy to carry out
maintenance, is inexpensive, and is easy to use in practice.
[0006] A molding device for continuous casting equipped with an
agitator according to an embodiment of the present invention is a
device which receives liquid-phase melt of a conductive material
and from which a solid-phase cast product is taken out through the
cooling of the melt. The molding device includes a casting mold
including a casting space that includes an inlet and an outlet at a
central portion of a substantially cylindrical side wall and a
magnetic field generation device receiving chamber that is formed
in the side wall and is positioned outside the casting space, the
casting mold receiving the liquid-phase melt from the inlet into
the casting space and discharging the solid-phase cast product from
the outlet through the cooling in the casting space, and an
agitator provided so as to correspond to the casting mold, the
agitator including a magnetic field generation device having an
electrode unit that includes first and second electrodes supplying
current to at least the liquid-phase melt present in the casting
space, and a permanent magnet that applies a magnetic field to the
liquid-phase melt. The magnetic field generation device is received
in the magnetic field generation device receiving chamber of the
casting mold, generates magnetic lines of force toward a center in
a lateral direction, makes the magnetic lines of force pass through
a part of the side wall of the casting mold and reach the casting
space, and applies lateral magnetic lines of force, which cross the
current, to the melt.
BRIEF DESCRIPTION OF DRAWINGS
[0007] FIG. 1(a) is a view illustrating the entire structure of an
embodiment of the invention, and FIGS. 1(b) and 1(c) are
explanatory views illustrating the operation thereof.
[0008] FIG. 2(a) is an explanatory plan view taken along line
II(a)-II(a) of FIG. 1 and FIG. 2(b) is an explanatory view
illustrating the bottom of an outer casting mold.
[0009] FIG. 3(a) is an explanatory plan view of a magnetic field
generation device 31 of an agitator 3, and FIG. 3(b) is an
explanatory plan view of a modified example thereof.
[0010] FIG. 4(a) is a plan view of another modified example of the
magnetic field generation device 31 of the agitator 3, and FIG.
4(b) is an explanatory plan view of a modified example thereof.
[0011] FIG. 5 is a view illustrating the entire structure of
another embodiment of the invention.
[0012] FIG. 6 is a view illustrating the entire structure of
another embodiment of the invention.
[0013] FIG. 7 is a view illustrating the entire structure of still
another embodiment of the invention.
[0014] FIG. 8(a) is a view illustrating the entire structure of yet
another embodiment of the invention, FIG. 8(b) is a cross-sectional
view taken along line VIII(b)-VIII(b) of FIG. 8(a), FIG. 8(c) is a
cross-sectional view taken along line VIII(c)-VIII(c) of FIG. 8(a),
FIG. 8(d) is an explanatory plan view of a magnetic field
generation device, and FIG. 8(e) is an explanatory plan view of a
lid.
[0015] FIG. 9(a) is a view illustrating the entire structure of
still another embodiment of the invention, FIG. 9(b) is a
cross-sectional view taken along line IX(b)-IX(b) of FIG. 9(a), and
FIG. 9(c) is an explanatory plan view of a magnetic field
generation device.
[0016] FIG. 10 is a view illustrating the entire structure of yet
another embodiment of the invention.
DESCRIPTION OF EMBODIMENTS
[0017] For deeper understanding of an embodiment of the invention,
an electromagnetic agitator, which uses electricity as power, of
continuous casting equipment in the related art will be described
briefly.
[0018] In the related art, a fixed amount of melt M of non-ferrous
metal is discharged from a melt receiving box that is called a
tundish and is poured into a casting mold that is provided on the
lower side. Cooling water for cooling the casting mold is
circulated in the casting mold. Accordingly, high-temperature melt
starts to solidify from the outer periphery thereof (a portion
thereof close to the casting mold) from the moment that the
high-temperature melt comes into contact with the casting mold.
[0019] Since the melt, which is positioned at the central portion
of the casting mold, is distant from the wall of the casting mold
that is being cooled, the solidification of the melt positioned at
the central portion of the casting mold is obviously later than
that of the melt positioned at the peripheral portion of the
casting mold. For this reason, two kinds of melt, that is, liquid
(liquid-phase) melt and a solid (solid-phase) cast product are
simultaneously present in the casting mold while being adjacent to
each other with an interface interposed therebetween. Further,
generally, if melt is solidified too rapidly, gas remains in the
cast product (product) having been changed into a solid and causes
the quality of the product to deteriorate. For this reason,
degassing is facilitated by the agitating of the melt that is not
yet solidified. The electromagnetic agitator, which uses
electricity as power, has been used for the agitating in the
related art.
[0020] However, when such an electromagnetic agitator is used,
there are various difficulties as described above.
[0021] Accordingly, the invention is to provide a molding device
for continuous casting equipped with an agitator that does not use
the electromagnetic agitator using electricity as power and uses
permanent magnets.
[0022] An embodiment of the invention will be described in more
detail below.
[0023] The entire structure of an embodiment of the invention is
illustrated in FIG. 1(a). FIG. 2(a) is an explanatory plan view
taken along line II(a)-II(a) of FIG. 1(a), and mainly illustrates a
part of an agitator 3 and a casting mold 2, and FIG. 3(a) is an
explanatory plan view of the magnetic field generation device 31 of
the agitator 3.
[0024] As understood from FIG. 1(a), a device according to an
embodiment of the invention broadly includes a melt supply unit 1
that supplies melt M of non-ferrous metal of a conductor
(conductive body), such as Al, Cu, Zn, or an alloy of at least two
of them, or an Mg alloy, or other metal; a casting mold 2 that
receives the melt from the melt supply unit 1; and an agitator 3
that agitates the melt M present in the casting mold 2. A central
portion of the casting mold 2 forms a so-called casting space 2A(1)
that includes an inlet 2A(1)1 and an outlet 2A(1)2.
[0025] The melt supply unit 1 includes a tundish (melt receiving
box) 1A that receives melt M from a ladle (not illustrated) or the
like. The melt M is stored in the tundish (melt receiving box) 1A,
inclusion is removed from the melt, and the melt M is supplied to
the casting mold 2 from a lower opening 1B of the tundish at a
constant supply rate. Only the tundish (melt receiving box) 1A is
illustrated in FIG. 1.
[0026] The casting mold 2 is adapted in this embodiment so that a
columnar product P (billet) is taken out from the casting mold. For
this purpose, the casting mold 2 is formed so as to have a
substantially cylindrical double structure (of which the
cross-section has a ring shape). That is, the casting mold 2
includes an inner casting mold 21 and an outer casting mold 22 that
are fitted to each other. The inner casting mold 21 is provided on
the inside and made of a non-conductive material (non-conductive
refractory material) such as graphite (carbon). The outer casting
mold 22 is provided on the outside and made of a conductive
material (conductive refractory material), such as aluminum or
copper.
[0027] As described in detail below, the magnetic field generation
device 31 is assembled so as to be received within the side wall of
the outer casting mold 22. Meanwhile, since the technical idea is
the same as described above even when a prismatic product (slab) is
taken out, the technical idea of an embodiment to be described
below can be applied as it is. Briefly, the shapes of components
corresponding to a rectangular slab, which is a product, are merely
changed.
[0028] The casting mold 2 further includes a water jacket 23
outside the outer casting mold 22.
[0029] The water jacket 23 is to cool the melt M that flows into
the inner casting mold 21. That is, cooling water flows into the
water jacket 23 from an inlet (not illustrated) and is circulated
in the water jacket 23, the outer portion of the outer casting mold
22 is cooled by the cooling water, and the cooling water is
discharged from an outlet (not illustrated). The melt M is rapidly
cooled by the water jacket 23. Since water jackets having various
known structures may be employed as the water jacket 23, the
detailed description thereof will not be provided here.
[0030] In addition, a plurality of electrode insertion holes 2a,
2a, . . . into which electrodes 32A to be described below are
inserted are formed at a predetermined interval on the
circumference of the casting mold 2 having the above-mentioned
structure. The electrode insertion holes 2a are formed so as to be
inclined downward toward the center of the casting mold 2. For this
reason, if the surface of the melt M is lower than the upper
openings of the electrode insertion holes 2a even though the melt M
is contained in the casting mold 2, there is no concern that the
melt M will leak to the outside.
[0031] As described above, briefly, the agitator 3 is provided so
as to be built in the side wall of the casting mold 2. The agitator
3 includes a permanent magnet type magnetic field generation device
31, and a pair of upper and lower electrodes (positive and negative
electrodes) 32A and 32B.
[0032] In particular, as understood from FIG. 3(a), the magnetic
field generation device 31 is formed in the shape of a ring (in a
frame shape). The entire inner peripheral portion of the magnetic
field generation device may be magnetized to an N pole, and the
entire outer peripheral portion of the magnetic field generation
device may be magnetized to an S pole. Further, four portions of
the inner and outer peripheral portions may be partially magnetized
to an N pole and an S pole as illustrated in, for example, FIG.
3(a), respectively.
[0033] As understood from the following description, the magnetic
field generation device 31 does not necessarily need to be formed
in the shape of a ring, and may be divided. That is, for example,
as illustrated in FIG. 8(d), the cross-section of the magnetic
field generation device may be formed of a plurality of arc-shaped
permanent magnet pieces (FIG. 4). As briefly described above,
particularly, as understood from FIG. 1(a), the magnetic field
generation device 31 is assembled in the outer casting mold 22.
[0034] In more detail, as understood from FIG. 1(a), the outer
casting mold 22 includes a magnetic field generation device
receiving chamber 22a which is formed in the side wall thereof and
has a ring-shaped cross-section and of which a lower portion forms
a release port. The magnetic field generation device receiving
chamber 22a is also understood from FIG. 2(b). FIG. 2(b) is a view
of the outer casting mold 22 when the outer casting mold 22 is seen
from below. In particular, as understood from FIG. 1(a), the
magnetic field generation device 31 also having a ring-shaped
cross-section is received in the magnetic field generation device
receiving chamber 22a, which has a ring-shaped cross-section and of
which the lower portion is opened, from below so that the position
of the magnetic field generation device in the vertical direction
can be adjusted by movement. That is, the magnetic field generation
device 31 is provided so that the height of the magnetic field
generation device can be adjusted in the magnetic field generation
device receiving chamber 22a by desired units (not illustrated).
Accordingly, it is possible to more efficiently agitate the melt M
as described below by adjusting the height of the magnetic field
generation device so as to correspond to liquid-phase melt M as
understood from FIG. 1(a). The lower opening of the magnetic field
generation device receiving chamber 22a is closed by a ring-shaped
lid 22B. The lid 22B may be formed so as to include discharge
channels 22B (1) for discharging cooling water to the outside such
as a lid 22B of FIG. 8(a) to be described below.
[0035] As described above, the four portions of the magnetic field
generation device 31 are magnetized and form pairs of magnetic
poles 31a, 31a, . . . as illustrated in FIG. 3(a). That is, a
portion of each of the magnetic poles 31a, 31a facing the inside of
the ring-shaped magnetic field generation device is magnetized to
an N pole, and a portion thereof facing the outside of the
ring-shaped magnetic field generation device is magnetized to an S
pole. Accordingly, magnetic lines of force ML generated from the N
pole horizontally pass through the melt M that is present in the
casting mold 2.
[0036] The magnetization may be contrary to this. That is, the
inner portions of all magnetic poles may be magnetized to a certain
pole and the outer portions thereof may be magnetized to an
opposite pole. One of additional characteristics of the invention
is that a plurality of magnetic poles are disposed at a plurality
of positions surrounding the melt M, which is not yet solidified,
as understood from FIG. 3(a). Accordingly, it is possible to
improve the quality of the product P by agitating all the melt M
with an electromagnetic force that is generated according to
Fleming's rule by magnetic lines of force and current as described
below. Therefore, the number of the magnetic poles is four in FIG.
3(a), but is not limited to four and may be arbitrary. Further, as
described above, the magnetic field generation device 31 does not
need to be formed of a ring-shaped single body, and may be divided
into a plurality of magnet bodies (magnet pieces), of which the
number is arbitrary, as illustrated in FIG. 8(d).
[0037] In FIG. 1(a), current flows between the pair of electrodes
32A and 32B through the melt M and a cast product (product) P. One
electrode 32A may be used, but a plurality of electrodes 32A may be
used. In this embodiment, two electrodes 32A are used. The
electrodes 32A are formed in the shape of a probe.
[0038] The respective electrodes 32A are inserted into the
above-mentioned electrode insertion holes 2a. That is, the
electrodes 32A penetrate into the casting mold 2 (the inner casting
mold 21 and the outer casting mold 22) from the water jacket 23.
Inner ends of the electrodes 32A are exposed to the inside of the
inner casting mold 21, come into contact with the melt M, and
conduct electricity to the melt M. Outer ends of the electrodes 32A
are exposed to the outside of the water jacket 23. The outer ends
are connected to a power supply 34 that can supply variable direct
current. The power supply 34 may have the function of an AC power
supply as described below, and may have a function of changing
frequency. The electrodes 32A may be supported above the upper
opening of the casting mold 2 without penetrating the side wall of
the casting mold 2 so that the inner ends of the electrodes 32A are
inserted into the melt M from the surface of the melt M flowing
into the casting mold 2. The electrodes 32A may be electrically
connected to the inner casting mold 21 made of graphite or the
like.
[0039] The number of electrodes used as the electrodes 32A may be
arbitrary, and an arbitrary number of the electrodes 32A may be
inserted into arbitrary electrode insertion holes of the electrode
insertion holes 2a, 2a, . . . .
[0040] In FIG. 1(a), the lower electrode 32B is provided so that
the position of the lower electrode 32B is fixed. The electrode 32B
is formed of a roller type electrode. That is, the lower electrode
32B includes a rotatable roller 32Ba at the end thereof. The roller
32Ba comes into press contact with the outer surface of a columnar
product P as a cast product (a billet or a slab) that is extruded
in a solid phase state. Accordingly, as the product P extends
downward, the roller 32Ba is rotated. That is, when the product P
is extruded downward, the product P extends downward in FIG. 1
while coming into contact with the roller 32Ba and rotating the
roller 32Ba.
[0041] Accordingly, when a voltage is applied between the pair of
electrodes 32A and 32B from the power supply 34, current flows
between the pair of electrodes 32A and 32B through the melt M and
the product P. As described above, the power supply 34 is adapted
so as to be capable of controlling the amount of current flowing
between the pair of electrodes 32A and 32B. Therefore, it is
possible to select current where the liquid-phase melt M can be
agitated most efficiently in a relationship with the magnetic lines
of force ML.
[0042] Next, the operation of the device having the above-mentioned
structure will be described.
[0043] In FIG. 1(a), a fixed amount of the melt M, which is
discharged from the tundish (melt receiving box) 1A, is input to
the upper portion of the casting mold 2. The casting mold 2 is
cooled through the circulation of water in the water jacket 23, so
that the melt M present in the casting mold 2 is rapidly cooled and
solidified. However, the melt M present in the casting mold 2 has a
two-phase structure where the upper portion of the melt is liquid
(liquid phase), the lower portion thereof is solid (solid phase),
and the upper and lower portions of the melt are adjacent to each
other at an interface IT0. When passing through the casting mold 2,
the melt M is formed in the shape (a columnar shape in this
embodiment) corresponding to the shape of the casting mold.
Accordingly, a product P as a slab or billet is continuously
formed.
[0044] Further, since the permanent magnet type magnetic field
generation device 31 is received in the side wall of the casting
mold 2 as understood from FIG. 1(a) and the like, the magnetic
field (magnetic lines of force ML) of the magnetic field generation
device reaches the melt M, which is present in the casting mold 2,
in the lateral direction. In this state, when direct current is
supplied to the lower electrode 32B from the upper electrodes 32A
by the power supply 34, the current flows to the lower electrode
32B from the upper electrodes 32A through the melt (liquid phase) M
of aluminum or the like and the product (solid phase) P. At this
time, the current crosses the magnetic lines of force ML, which are
generated from the permanent magnet type magnetic field generation
device 31, substantially at right angles to the magnetic lines of
force. Accordingly, rotation occurs in the liquid-phase melt M in
accordance with Fleming's left-hand rule. The melt M is agitated in
this way, so that impurities, gas, and the like contained in the
melt M float and so-called degassing is actively performed.
Accordingly, the quality of the product (a slab or a billet) P is
improved.
[0045] Now, cooling capacity is increased or reduced by the water
jacket 23 or the like, the solidification rate of the melt M is
changed and the interface IT0 between the melt (liquid-phase) M and
a product (solid-phase) P moves up and down according to this. That
is, when cooling capacity is increased, the interface IT0 moves up
like an interface IT1 as illustrated in FIG. 1(b). When cooling
capacity is reduced, the interface IT0 moves down like an interface
IT2 as illustrated in FIG. 1(c). Further, it is preferable that the
magnetic field generation device 31 be moved up and down according
to the positions of the interfaces IT0, IT1, and IT2 in order to
efficiently agitate the melt M. Accordingly, it is possible to
obtain a product P as a high-quality product by reliably and
efficiently agitating the melt M. For this purpose, the magnetic
field generation device is adapted so that the height of the
magnetic field generation device 31 can be adjusted in the vertical
direction according to the heights of these interfaces IT1 and IT2
as illustrated in FIGS. 1(b) and 1(c) and the position of the
magnetic field generation device 31 can be kept. Accordingly, it is
possible to efficiently agitate the melt M as described above.
[0046] On the contrary, the double structure of the casting mold 2
may be formed so that the inner portion of the casting mold is made
of a conductive material and the outer portion thereof is made of a
non-conductive material. In this case, at least the electrodes 32A
may come into electronically contact with the conductive material
that forms the inner portion of the casting mold. Even in this
case, a magnetic field generation device receiving chamber 22a may
be formed in an outer member.
[0047] Further, the casting mold 2 may have not a double structure
but a single structure. In this case, the casting mold 2 may be
made of only a conductive material, and the electrodes 32A may
conduct electricity to the casting mold 2. The structure of the
other electrode 32B may be the same as described above.
[0048] On the contrary, the casting mold 2 may be made of only a
non-conductive material. In this case, it is necessary to make the
electrodes 32A conduct electricity to the melt M present in the
casting mold 2 by making the electrodes 32A penetrate into the
casting mold 2 as illustrated in FIG. 1(a).
[0049] In these cases, obviously, a magnetic field generation
device receiving chamber 22a may be formed in a member having a
single structure.
[0050] A magnetic field generation device 31A of FIG. 3(b) may be
used instead of magnetic field generation device 31 of FIG. 3(a).
The magnetization direction of the magnetic field generation device
31A of FIG. 3(a) is opposite to that of the magnetic field
generation device 31 of FIG. 3(b). Both the magnetic field
generation devices have the same function.
[0051] Further, magnetic field generation devices 31-2 and 31A-2 of
FIGS. 4(a) and 4(b) may be used instead of the magnetic field
generation devices 31 and 31A of FIGS. 3(a) and 3(b). The magnetic
field generation devices 31-2 and 31A-2 of FIGS. 4(a) and 4(b) are
adapted so that a plurality of rod-like permanent magnets PM are
fixed to the inside of a ring-shaped support (yoke) SP. These have
the same function.
[0052] Furthermore, an electrode, which includes the roller 32Ba at
the end thereof, has been described as the lower electrode 32B in
the above-mentioned embodiment. However, the lower electrode does
not need to necessarily include the roller 32Ba. Even though a
product P is continuously extruded, the electrode 32B only has to
conduct electricity to the product P and may employ various
structures. For example, an elastic member having a predetermined
length is used as the electrode 32B and is bent, for example, so as
to be convex upward or downward in FIG. 1, and the end of the
elastic member comes into press contact with the cast product P by
the force of restitution. In this state, the cast product P may be
allowed to extend downward.
[0053] According to the above-mentioned embodiment of the
invention, it is possible to obtain the following effects.
[0054] In the embodiment of the invention, melt M that is not yet
solidified is agitated to give movement, vibration, and the like to
the melt M, so that a degassing effect and the uniformization and
refinement of the structure are achieved.
[0055] In more detail, since the magnetic field generation device
31 is adapted so as to be capable of being adjusted in the vertical
direction in the embodiment of the invention, it is possible to
obtain a high-quality product P by reliably agitating the melt M.
This is one of the characteristics of the invention as described
above, and an idea, in which a magnetic field generation device 31
provided outside the casting mold is moved up and down in a device
that is apt to be high temperature and large in size and hardly has
an empty space as in the embodiment of the invention, itself is an
idea that is not accustomed to those skilled in the art.
Accordingly, a technique of the invention, in which a magnetic
field generation device is received in a casting mold and can be
adjusted in the vertical direction, is a technical idea that is
peculiar to the inventor.
[0056] Further, since the magnetic field generation device 31 is
formed in the embodiment of the invention so that a plurality of
magnetic poles are disposed at the positions surrounding the melt M
or a ring-shaped magnet surrounding the melt M is disposed, it is
possible to efficiently agitate all the melt M with an
electromagnetic force that is generated according to Fleming's rule
by magnetic lines of force and current. Accordingly, it is possible
to obtain a product P as a high-quality product. That is, in the
embodiment of the invention, it is possible to efficiently agitate
the melt M by making the best use of an electromagnetic force that
is generated according to Fleming's rule. In addition, the axis of
the rotation of the melt M, which is caused by this agitating of
the melt, is an axis parallel to the center axis of the product P
in FIG. 1(a). Accordingly, it is possible to obtain a high-quality
product as a product P by making the rotational drive of the melt M
reliable.
[0057] Moreover, in the embodiment of the invention, melt M is
agitated with an electromagnetic force that is generated according
to Fleming's rule and is agitated by the cooperation between small
current flowing in the melt M and a magnetic field generated from
the magnetic field generation device 31. Accordingly, it is
possible to obtain a device that stably and continuously expects
reliable agitation unlike melting and agitation performed using the
intermittent flow of large current according to the principle of
arc welding or the like and has low noise and high durability.
[0058] It is obvious that the above-mentioned effects are obtained
from all embodiments to be described below.
[0059] Meanwhile, direct current has been supplied between the
electrodes 32A and 32B in the above description, but alternate
current having a low frequency of about 1 to 5 Hz may be supplied
from the power supply 34. In this case, the melt M does not rotate
but repeatedly vibrates according to the cycle thereof in the
relationship with a magnetic field that is generated from the
magnetic field generation device 31. Impurities are removed from
the melt M even by the vibration. This modified example may be
applied to all embodiments to be described below. In this case, it
is obvious that a power supply having a function of changing
frequency is employed as the power supply 34.
[0060] Further, the realization of mass production facilities is
currently required in the industry. It is essential to realize a
casting mold that is as small as possible when mass production is
considered.
[0061] Here, the electromagnetic agitating device in the related
art can cope with a case where several slabs or billets are
produced at one time. However, at present, there is a demand for
the production of billets of which the number exceeds 100. The
electromagnetic agitator in the related art cannot cope with this
demand.
[0062] However, permanent magnets are used as the magnetic field
generation device in the device of the invention. For this reason,
it is possible to make the device very compact in comparison with
the electromagnetic agitator that is supplied with large current.
Accordingly, it is possible to sufficiently realize a molding
device for a mass production facility. Further, since the magnetic
field generation device is permanent magnet type, it is possible to
obtain a device having effects, such as no heat generation, power
saving, energy saving, and less maintenance, as a magnetic field
generation device.
[0063] FIG. 5 illustrates another embodiment of the invention.
[0064] More current is supplied to this liquid-phase melt M to
generate a larger electromagnetic force so that the melt M is
rotationally driven.
[0065] This embodiment is different from the embodiment of FIG.
1(a) in the structure of a casting mold 2A. Other structures are
substantially the same as FIG. 1(a). Accordingly, the detailed
description thereof will not be repeated here.
[0066] That is, the casting mold 2A of this embodiment includes a
substantially cylindrical casting mold body 2A1. The casting mold
body 2A1 includes a circumferential groove 2A1(a) that is formed on
the inner peripheral surface thereof. An insulating film 2A2 is
formed on the inner surface (the peripheral surface and the
bottoms) of this groove, and an embedded layer 2A3 is formed by
embedding the same conductive material as the casting mold body 2A1
on the insulating film 2A2. An insulating layer portion is formed
of the insulating film 2A2 and the embedded layer 2A3. The
insulating layer portion is formed on a part of the inner surface
of the casting mold, and functions as a portion that does not allow
the flow of current from the casting mold.
[0067] This insulating layer portion is formed on a slightly lower
portion of the inner surface of the casting mold body 2A1.
[0068] Accordingly, current is hardly allowed to flow to the cast
product P from the insulating layer portion of the casting mold
body 2A1, that is, a portion adjacent to the cast product P.
[0069] In addition, a terminal 2A4 is provided on the outer
periphery of the casting mold body 2A1. Power can be supplied to
the casting mold 2A from the power supply 34 through this terminal
2A4.
[0070] When a voltage is applied between the terminal 2A4 and the
electrode 32B by the power supply 34 in the device having this
structure, current flows in the casting mold body 2A1, the melt M,
and the cast product P. Since current does not flow in the
insulating film 2A2 and the embedded layer 2A3 at this time, larger
current flows in the melt M. Accordingly, a larger electromagnetic
force, which allows the melt M to be agitated, is obtained.
[0071] FIG. 6 illustrates still another embodiment.
[0072] This embodiment is a modification of the embodiment of FIG.
1(a).
[0073] This embodiment is different from the embodiment of FIG.
1(a) in the disposition of the upper electrodes 32A of FIG. 1(a).
That is, in this embodiment, one electrode 32A0 is disposed or a
plurality of electrodes 32A0 are disposed annularly, these
electrodes 32A0 are supported by arbitrary units other than the
casting mold 2A and the like (the casting mold 2A and the water
jacket 23), and a lower end portion of each of the electrodes 32A0
is inserted into the melt M. Accordingly, it is possible to adjust
the length of the lower end portion, which is inserted into the
melt M, of the electrode 32A0 with large degree of freedom
regardless of the casting mold 2A and the like. Moreover,
obviously, a normal mold may be used as the casting mold 2A or the
like, and electrode insertion holes 2a for electrodes 32A1 do not
need to be formed in the casting mold 2A or the like. Therefore, it
is also possible to prevent the increase in the manufacturing costs
of these.
[0074] Other structures are the same as the embodiment of FIG.
1(a).
[0075] FIG. 7 illustrates yet another embodiment.
[0076] This embodiment may be regarded as a modified example of the
embodiment of FIG. 6.
[0077] The embodiment of FIG. 7 is assumed as a device that can be
operated when melt M is poured into a casting mold 2A, which is
provided on the lower side, from a tundish (melt receiving box) 1A,
which is provided on the upper side, as continuous melt with no
interruption. That is, it is assumed that the melt M present in the
tundish (melt receiving box) 1A and the melt M present in the
casting mold 2A are integrally connected to each other.
[0078] In FIG. 6, the electrodes 32A0 are inserted into the melt M
present in the casting mold 2. However, in FIG. 7, an electrode
32A1 is supported by arbitrary units so as to be inserted into the
melt M present in the tundish (melt receiving box) 1A on the
premise of the above-mentioned case. Accordingly, it is possible to
obtain the same advantage as the above-mentioned embodiment of FIG.
6. In addition, it is possible to set and adjust a distance between
the tundish (melt receiving box) 1A and the casting mold 2A or the
like regardless of the electrode 32A1.
[0079] Other structures are substantially the same as FIG. 6.
[0080] FIGS. 8(a) to 8(d), FIGS. 9(a) to 9(c), and FIG. 10
illustrate other embodiments of the invention, respectively.
[0081] The same members of these embodiments as the members of the
above-mentioned embodiment are denoted by the same reference
numerals and the description thereof will not be repeated.
[0082] In these embodiments, a water jacket for cooling does not
need to be separately provided, a water flow chamber 22a(2), which
functions as both a cooling chamber and a magnetic field generation
device receiving chamber, is formed in the side wall of a casting
mold 2, that is, the side wall of the outer casting mold 22, and a
magnetic field generation device 31 as a permanent magnet is
received in the water flow chamber 22a(2) so that the position of
the magnetic field generation device can be adjusted in the
vertical direction.
[0083] Meanwhile, a magnetic field generation device receiving
space (magnetic field generation device receiving chamber) 22a(2)
illustrated in FIG. 8(c) may be divided so as to receive a
plurality of permanent magnet pieces 31A, which are illustrated in
FIG. 8(d) and disposed at a predetermined interval, respectively.
For example, the magnetic field generation device receiving space
may be formed of a plurality of partial magnetic field generation
device receiving chambers having an arc-shaped cross-section.
[0084] First, a device of manufacturing a billet of the embodiment
illustrated in FIGS. 8(a) to 8(e) will be described.
[0085] That is, as understood from FIG. 8(a), the outer casting
mold 22 includes a water flow chamber 22a(2) that is opened
downward and has a ring-shaped cross-section, and the water flow
chamber 22a(2) is hermetically-sealed by a lid 22B(1). FIG. 8(b) is
a view illustrating the inner casting mold 21 and the outer casting
mold 22 taken along line VIII(b)-VIII(b) from below when the lid
22B(1) is removed. This lid 22B(1) forms a part of the casting mold
2.
[0086] As understood from FIG. 8(a), a magnetic field generation
device 31, which is formed of a plurality of permanent magnet
pieces 31A (FIG. 8(c)) having an arc-shaped cross-section, is
received in the ring-shaped water flow chamber 22a(2) serving as a
magnetic field generation device receiving space (receiving
chamber) so as to be capable of being adjusted in the vertical
direction. That is, the water flow chamber (cooling chamber) 22a(2)
functions as both a cooling water flow chamber and a magnetic field
generation device receiving chamber. A plan view of these permanent
magnet pieces 31A is illustrated in FIG. 8(d). The inner portion of
each of the permanent magnet pieces 31A is magnetized to an N pole
and the outer portion thereof is magnetized to an S pole. The
magnetization may be contrary to this. That is, the magnetic field
generation device 31 is provided so that the height of the magnetic
field generation device can be adjusted in the water flow chamber
22a(2) by arbitrary units (not illustrated). Accordingly, it is
possible to more efficiently agitate the melt M by adjusting the
height of the magnetic field generation device so as to correspond
to liquid-phase melt M as described above.
[0087] The lower opening of the water flow chamber 22a(2) is closed
by the above-mentioned ring-shaped lid 22B. A plan view of the lid
22B is illustrated in FIG. 8(e). As understood from FIGS. 8(e) and
8(a), a plurality of discharge channels 22B(1) for cooling water
are formed in the lid 22B(1). As understood from FIGS. 8(a) and
8(e), the plurality of discharge channels 22B(1) include a
plurality of inlets 22B(1)a1 that are opened to the upper surface
of the lid 22B, and include outlets 22B(1)a2 on the peripheral
surface of the lid 22B. Accordingly, cooling water present in the
water flow chamber 22a(2) enters from the plurality of inlets
22B(1)a1, flows out of the outlets 22B(1)a2, and is jetted to the
outer periphery of the product P to cool the product P. That is,
cooling water enters the water flow chamber 22a(2) from inlets (not
illustrated), is circulated in the water flow chamber while cooling
the product, and is discharged while being jetted to the outside
from the discharge channels 22B(1).
[0088] Since the operation of the above-mentioned device of FIGS.
8(a) to 8(e) is the same as that of the above-mentioned embodiment,
the description thereof will not be repeated.
[0089] Meanwhile, the magnetic field generation device 31 has been
formed of the plurality of permanent magnet pieces 31A in the
above-mentioned embodiment of FIGS. 8(a) to 8(e). However, it is
obvious that the magnetic field generation device may be integrally
formed as in FIG. 3(a). Further, the water flow chamber 22a(2)
serving as the magnetic field generation device receiving space is
formed in a circumferential shape as understood from FIG. 8(b).
However, the water flow chamber is not limited to this shape, and
may be formed of a plurality of cell chambers that are divided in
the circumferential direction and have an arc-shaped cross-section.
It is preferable that cooling water can flow in each cell chamber
and the permanent magnet piece 31A be received in each cell chamber
so as to be capable of moving up and down.
[0090] In the device of FIGS. 8(a) to 8(e), the magnetic field
generation device 31 is not provided outside the casting mold 2,
and a cavity (water flow chamber 22a(2)) is formed in the casting
mold 2 (outer casting mold 22) and the magnetic field generation
device 31 is received in the cavity. Accordingly, it is possible to
obtain the following characteristics. [0091] A permanent magnet,
which is small and has a small capacity, may be used as the
magnetic field generation device 31.
[0092] That is, if the magnetic field generation device 31 is
provided outside the casting mold, it is inevitable that a distance
between the magnetic field generation device 31 and the melt M is
slightly increased. However, since the magnetic field generation
device is built in the casting mold 2 in this embodiment, the
distance between the magnetic field generation device 31 and the
melt M is reduced. Accordingly, a permanent magnet, which is small
and has a small capacity, may be used to obtain the same agitating
performance. [0093] It is possible to significantly improve a
working property.
[0094] That is, when this device is operated, a plurality of
inspectors should be positioned around the device to perform
various kinds of measurement, nondestructive inspection, and the
like and should perform such the measurement and the like for the
check of a product P. However, in the case of the magnetic field
generation device that is provided outside, the increase in size
and volume cannot be avoided and it cannot be denied that it is
difficult to perform such the measurement since a strong magnetic
field is generated. However, since the magnetic field generation
device 31 is provided in the casting mold 2 in this embodiment, a
volume is not increased and the intensity of a magnetic field
emitted to the outside is reduced. For this reason, it is easy to
perform various kinds of measurement and the like. [0095] It is
possible to significantly improve productivity.
[0096] That is, it is possible to reduce time required for the
above-mentioned measurement and the like. As a result, it is
possible to increase the manufacturing rate of a product P per unit
time. [0097] It is possible to reduce size.
[0098] That is, since the magnetic field generation device 31 is a
built-in type, it is possible to provide a device that is small as
a whole as much as that. [0099] It is possible to save a space of
an installation location.
[0100] That is, since the magnetic field generation device 31 is a
built-in type when the device is regarded as a device manufacturing
the same product P although being the same as described above, the
size of the device is reduced as a whole. Accordingly, it is
possible to install the device even at a narrow place. As a result,
flexibility is obtained in the usefulness of the device.
[0101] The above-mentioned effects will be described below from a
different standpoint.
[0102] When a product P is manufactured by this device, for
example, five or six workers gather around the device and should
perform high-density works (works for monitoring and preventing the
leakage of melt, works for monitoring and preventing the jet of
melt, and the like) in a short time. When these works are performed
by a plurality of workers, a working property is good in the
built-in type device of this embodiment as compared to a case where
the magnetic field generation device 31 is provided outside so as
to protrude. That is, since the external appearance of the device
has the same dimensions as the dimensions of a device that does not
include the magnetic field generation device 31 that is a device in
the related art, the device of this embodiment is very easy to use
at the work site.
[0103] Further, it is preferable that the magnetic field generation
device 31 be close to the melt M as much as possible in order to
reliably apply a magnetic field to the melt M, and this is realized
in a built-in type.
[0104] When the magnetic field generation device 31 is provided
outside, the influence of a magnetic field on various measuring
instruments such as temperature sensors should be considered.
However, since the influence thereof is reduced in a built-in type,
a built-in type is more advantageous in measurement. That is, when
a product P, such as a slab or a billet, is manufactured, the
measurement, management, and the like of temperature in several
positions are very important to maintain the quality of a product.
This embodiment is very advantageous in the measurement of
temperature and the like.
[0105] If a built-in type magnetic field generation device as in
this embodiment is used instead of the magnetic field generation
device provided outside, the size, weight, and volume of a device
may be reduced when the same magnetic field is applied to the melt
M. Accordingly, the device is easy to use. That is, since the
respective components of this device are consumables, the
respective components of this device need to be replaced whenever a
predetermined operation time has passed. However, since the
magnetic field generation device 31 is small and light, a work for
replacing the magnetic field generation device and the like are
very easily performed.
[0106] Since a work at the device of this embodiment is a work that
is performed at a so-called high temperature of about 700.degree.
C., the work is very dangerous for a worker. However, a magnetic
field generation device, which is small and of which the intensity
of a magnetic field is low, may be used as the magnetic field
generation device 31. Further, a tool, which is used for the
adjustment, maintenance, and the like of the device, is generally a
ferromagnetic body made of iron and safety shoes and the like are
also made of iron. However, if a magnetic field of the magnetic
field generation device 31, which is emitted by the outside, is
reduced a little, the safety of a security officer, a worker, a
measuring person, and the like is ensured.
[0107] It is obvious that the effects described above with
reference to FIGS. 8(a) to 8(e) are mentioned in not only the
device of FIG. 1 and the like but also devices for manufacturing a
slab that are to be described below and illustrated in FIGS. 9(a)
to 9(c) and 10.
[0108] FIGS. 9(a) to 9(c) illustrate a device for manufacturing a
slab. However, the basic technical idea of the device is the same
as described above except that a billet has a circular shape and a
slab has a rectangular shape. Accordingly, the same members are
denoted by the same reference numerals and the description thereof
will not be repeated.
[0109] A difference will be described below.
[0110] The weight of a slab as a product P is very heavy. For this
reason, a billet can be pulled in the horizontal direction, but a
slab as a product P is not obtained unless taken out in the
vertical direction. For this reason, a pedestal 51 is prepared, and
a product P is taken out while riding the pedestal 51 and being
gradually pulled downward. A lower electrode 32B is embedded in the
pedestal 51. A magnetic field generation device 31 is illustrated
in FIGS. 9(b) and 9(c). FIG. 9(b) is a cross-sectional view taken
along line IX(b)-IX(b) of FIG. 9(a), and FIG. 9(c) is a plan view
of the magnetic field generation device 31. Here, the magnetic
field generation device 31 uses four permanent magnet pieces 31A
and forms two pairs facing each other, but may use any one
pair.
[0111] FIG. 10 illustrates a modified example of FIG. 9(a).
[0112] In FIG. 10, a pair of electrodes 32A and 32B is used while
being inserted into melt M. The inventor confirmed by an experiment
that the melt M is agitated even though the electrodes 32A and 32B
are used in this way. That is, even though the pair of electrodes
32A and 32B is employed as illustrated in FIG. 10, the magnetic
lines of force generated from a magnetic field generation device 31
and current flowing between the pair of electrodes 32A and 32B flow
in various paths in the melt M and generate an electromagnetic
force according to Fleming's rule.
* * * * *