Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02541938 1997-11-12
ROLLED PLATE JOINING APPARATUS
AND
CONTINUOUS HOT ROLLING APPARATUS EQUIPPED WITH THE SAME
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
The present invention relates to a rolled plate joining apparatus for joining
the tailing end of a preceding rolled plate and the leading end of a
succeeding rolled
plate while traveling with the rolled plates in a hot rolling plant and to a
continuous
hot rolling apparatus equipped with the same.
DESCRIPTION OF THE RELATED ART
In conventional hot rolling plants (hot strip mills), bar materials rolled by
a
roughing mill are supplied separately to a finishing mill to obtain strip
materials
having a desired thickness. By such a means, however, all the rolled plates
are not
rolled uniformly, and therefore there are such problems that defects of
leading ends
and tailing ends are liable to occur thereby lowering the yield of the roiled
plates and it
is hard to increase the rolling speed due to such defects.
To solve the above problems, there are conventionally suggested joining
apparatuses for joining the tailing end of a preceding rolled plate and the
leading end
of a succeeding rolled plate so as to supply the rolled plates to a finishing
mill
successively (e.g., Japanese Unexamined Patent Publication Nos. 62-252603 and
63-
93408 and Japanese Patent Publication No. 5-139).
In the above-described rolled plate joining apparatuses, however, there are
such problems that (1) the automation (mechanization) is difficult and the
joined
sections cannot be rolled uniformly, (2) since it takes long time to weld wide
rolled
plates, the overall length of the plant is apt to be long, and (3) it is
difficult to secure a
satisfactory joined strength throughout the width of the rolled plates.
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Therefore, the inventors of the present invention thought out a rolled plate
joining apparatus capable of joining rolled plates with a satisfactory joined
strength
throughout the width in a short period of time and filled applications thereof
(e.g.,
Japanese Unexamined Patent Publication No. 8-10809).
Fig. 1 is an example of a rolled plate joining apparatus made by the
inventors of the present invention.
This rolled plate joining apparatus is equipped with a truck 3 that travels in
the rolling direction, tailing end pinch rolls 4 that are mounted on the truck
3 and can
be moved vertically with the tailing end of a preceding rolled plate 1 pinched
1o horizontally, leading end pinch rolls 5 that are mounted on the truck 3 and
can pinch
horizontally the leading end of a succeeding rolled plate 2, machining
apparatuses 6
for cutting the undersurface of the tailing end of the preceding rolled plate
1 and the
upper surface of the leading end of the succeeding rolled plate 2, and a
pressure
welding apparatus 7 for joining the preceding rolled plate 1 and the
succeeding rolled
i5 plate 2 with the machined surfaces of the preceding rolled plate 1 and the
succeeding
rolled plate 2 overlapped and reduced approximately to the thickness of the
rolled
plates 1 and 2.
Further, as is shown in Fig. 2, the rolled plate joining apparatus of Japanese
Unexamined Patent Publication No. 8-10809 is equipped with the truck 3 that
travels
2o with apparatuses mounted thereon, a tailing end clamping apparatus 9 that
can be
moved vertically between a pressure welding level H and a rolling level L by
an
elevating apparatus 8 with the tailing end of the preceding rolled plate
pinched
horizontally, a leading end clamping apparatus 10 for pinching and holding the
leading end of the succeeding rolled plate 2 at a pressure welding level L, a
machining
25 apparatus 11 for cutting simultaneously the undersurface of the tailing end
of the
preceding rolled plate 1 and the upper surface of the leading end of the
succeeding
rolled plate 2, a reduction keeping apparatus 12 for keeping the surfaces to
be cut in a
reducing atmosphere, and a pressure-welding apparatus 12 for pressure-welding
the
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CA 02541938 1997-11-12
overlapped sections.
The machining apparatus 11 is composed of a conical cutter 13 that is rotated
about an axis X slanted to the level and a traverse moving apparatus 14 for
moving
horizontally the conical cutter 13 throughout the width of the rolled plates
from a
position that is out of the position of the rolled plates. The conical cutter
13 has a pair
of truncated conical surfaces 13a, 13b whose tops are directed outward and the
uppermost part and the lowermost part of the truncated conical surfaces are
generally
horizontal, so that the uppermost part and the lowermost part of the truncated
conical
surfaces can touch the undersurface of the tailing end and the upper surface
of the
leading end simultaneously respectively. In passing, cutter tips 13c are
embedded in
the truncated conical surfaces 13a, 13b. Further, 15 indicates a traverse
moving table of
the traversing apparatus 14.
Further, Japanese Unexamined Patent Publication No. 7-214104 describes a
hot rolling plant wherein joining machine is used. As is shown in Fig. 3, this
hot
i5 rolling plant is provided with a sizing press 16b on the exit side of a
heating furnace
16a, and the leading end and the tailing end of a sheet bar 1 rolled by a
roughing mill
16c provided on the exit side thereof is sheared by a crop shear 16d. The
tailing end of
the sheared preceding sheet bar and the leading end of the sheared succeeding
sheet
bar are joined by a fuse-joining apparatus 17 and are subjected to finish
rolling by a
group of finishing mills 16e and the joined sheet bars are wound by a winding
machine 16f.
(1) In the rolled plate joining apparatus shown in Fig. 1 or 2, it is required
to
align the center lines of the preceding rolled plate 1 and the succeeding
rolled plate 2.
Fig. 4 shows a state wherein the center line of one rolled plate is not
aligned with the
center line of other rolled plate to be joined and if they are joined in this
state, plate
breaking or camber due to the defective joining will occur. Fig. 5 shows
misalignment
of the center lines in the joined sections of rolled plates having different
widths. ~ If
the center line of a preceding rolled plate and the center line of a
succeeding rolled
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CA 02541938 1997-11-12
plate are misaligned in this way, problems arise that will cause serious
troubles with
succeeding finishing rolling or the like.
(2) Further, the life of the conical cutter 13 of the rolled plate joining
apparatus shown in Fig. 2 is extremely short due to such factors that [1] the
conical
cutter 13 is exposed to a high-temperature atmosphere by the reduction keeping
apparatus, j2] the conical cutter 13 is rotated at a high speed by the driving
apparatus, [3]
the conical cutter 13 is moved horizontally in the width direction of the
rolled plates
by the traverse moving arparatus, and [4] use of the cutter tips for the
conical cutter
makes the heat capacity small. In addition, it is difficult to provide a
cooling
1o mechanism, because, for example, [1] the driving apparatus is attached to
the extremity
of the shaft of the conical cutter and [2] a key groove into which a key is
fitted is formed
in the inner circumferential surface of the conical cutter.
(3) Further, in the rolled plate joining apparatus, the cutting of the
surfaces
to be joined is required to be done in a short period of time. Because if the
cutting
time becomes long, the joining time becomes long to make the traveling
distance of
the joining apparatus long and therefore the rolling line becomes long.
Further, since
the surfaces to be cut during the cutting are covered with reducing flames to
prevent
them from being oxidized, the surfaces to be cut are at a high temperature and
therefore a lubricant cannot be used during the cutting. As a result, the
cutter tips are
abraded intensely, the life thereof is short, and therefore the cutter has to
be replaced
frequently. Further, if the cutter is damaged during the cutting, the
replacement takes
a longer time, and during that time, the joining operation and the rolling
operation
have to be stopped. The joining is carried out with a certain interval between
the
joining operations, but the heat capacity of the cutter is large, the cutter
tips are not
cooled in many cased until the next joining operation, and therefore the
temperature
of the cutter tips during the cutting is increased to make the life short.
(4) Further, in the hot rolling plant shown in Fig. 3, since the rolled plates
after the rough rolling are not wound, the rolling line becomes long. Then, in
this
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CA 02541938 1997-11-12
plant, the temperature of the rolled plates supplied to the finish rolling
machine is
lowered and the finish rolling cannot be carried out suitably in many cases.
Further,
in many cases, the joined sections bulge in the plate width direction, and
this bulge is
expanded by rolling in the succeeding step. Fig. 6 shows the shape of the
bulge at the
joined sections. The plate width at the joined position of the rolled plate 1
has a bulge
1a. Further, in .Fig. 7, the rolled plate 1 is tapered at the opposite ends to
form edge
drops 1b. Edge drops 1b cannot secure the precision of the plate thickness at
the
opposite ends and therefore are trimmed, resulting in a decrease in the yield.
The
plant shown in Fig. 3 does not have a correcting apparatus for correcting such
joined
1o sections or a defective thickness at the opposite ends due to rolling.
Furthermore,
since there is no shear before the winding machine, it is required to sever
the rolled
plates for every quantity of the rolled plates that can be wound by the
winding
machine and the ability capable of operating continuously by the joining
machine is
not used. In passing, Japanese Unexamined Patent Publication No. 7-24503
discloses a
post-forming machine for removing defective parts due to joining positioned on
the
exit side of a joining machine, but this post-forming machine cannot correct
edge
drops resulting from finish rolling.
SUMMARY OF THE INVENTION
2o The present invention has been thought out so as to solve the above-
described various problems. That is, a first object of the present invention
is to
provide a rolled plate joining apparatus that has a sensing apparatus for
aligning the
center lines of a preceding rolled plate and a succeeding rolled plate.
Further, a second object of the present invention is to provide a rolled plate
joining apparatus that has cutter cooling apparatuses capable of cooling
efficiently
conical cutters, and particularly cutter tips.
Still, a third object of the present invention is to provide a rolled plate
joining apparatus that allows a waiting cutter to be cooled rapidly, allows an
abrasion
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' CA 02541938 1997-11-12
preventive agent to be applied to a waiting cutter, and allows a cutter be
replaced
rapidly.
Further, a fourth object of the present invention is to provide a continuous
hot rolling apparatus that shortens a rolling line, improves the productivity
of strip
materials by continuous rolling and the preciseness of the width and thickness
of
plates, and increases the ability of adjusting the width of slabs to decrease
the types of
the widths of slabs on the side of a continuous casting machine to which the
slabs are
supplied to improve the productivity.
To attain the first object, according to the present invention, there is
to provided a rolled plate joining apparatus equipped with a truck that can
travel
reversibly in the rolling direction, tailing end pinch rolls that are mounted
on said
truck and can be moved vertically with the tailing end of a preceding rolled
plate
pinched horizontally, leading end pinch rolls that are mounted on said truck
and can
pinch horizontally the leading end of a succeeding rolled plate, machining
apparatuses
for cutting one surface of the tailing end of the preceding rolled plate and
the other
surface of the leading end of the succeeding rolled plate, and a pressure
welding
apparatus for compressing the preceding rolled plate and the succeeding rolled
plate
with the machined surfaces overlapped to reduce them approximately to the
thickness
of the rolled plates, comprising a tailing end centering apparatus placed
between said
tailing end pinch rolls and said pressure welding apparatus for pressing the
opposite
width ends of the tailing end of the rolled plate to align the center line of
said rolled
plate with the center line of said joining apparatus in the rolling direction
and a
leading end centering apparatus placed between said pressure welding
apparafius and
said leading end pinch rolls for pressing the opposite width ends of the
leading end of
the rolled plate to align the center line of said rolled plate with the center
line of said
joining apparatus in the rolling direction.
By the above constitution, the tailing end centering apparatus aligns the
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CA 02541938 1997-11-12
center line of a preceding rolled plate with the center line of the joining
apparatus in
the rolling direction at the tailing end of the preceding rolled plate. Herein
the term
"the center line of the joining apparatus in the rolling direction" means the
line along
which the center line of the rolled plate is to be passed and is generally the
center line
of the joining apparatus in the rolling direction but also includes lines
parallel to it.
Further, the leading end centering apparatus aligns the center line of a
succeeding
rolled plate with the center line of the joining apparatus in the rolling
direction at the
leading end of the succeeding rolled plate. Thus, the pressure welding can be
made
with the center line of a preceding rolled plate aligned with the center line
of a
l0 succeeding rolled plate.
In accordance with a preferred embodiment of the present invention, each
of said tailing end centering apparatus and said leading end centering
apparatus
comprises guide plates provided along the opposite width ends of the rolled
plate, a
lower rack plate having a rack on the upper surface in the plate width
direction and
~5 fixed to one of the guide plates, an upper rack plate having a rack on one
surface in the
plate width direction and fixed to the other of the guide plates, a pinion
arranged
between said lower rack plate and said upper rack plate and meshed with said
racks of
said rack plates; and a rack plate driving apparatus for extending or
retracting said
lower rack plate and said upper rack plate in the plate width direction.
2o In accordance with the above constitution, when the lower rack plate and
the upper rack plate are retracted or extended in the plate width direction by
the rack
plate driving apparatus, the guide plates fixed to the rack plates are moved
horizontally by the same distance in the width direction of the rolled plates
by the
action of the racks and the pinion. In the centering apparatuses, by setting
the left and
25 right guide plates to be at the same distance from the center line of the
joining
apparatus in the rolling direction, the left and right guide plates can be
moved by the
same distance from the center line of the joining apparatus in the rolling
direction at
all the time and therefore the center line of the rolled plate can be aligned
with the
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CA 02541938 1997-11-12
center line of the joining apparatus in the rolling direction.
Further, preferably, said tailing end centering apparatus has elevating
apparatuses and carries out a centering operation for aligning the center Iine
of the
rolled plate that is kept raised or lowered by said tailing end pinch rolls
with the center
line of the joining apparatus in the rolling direction.
According this constitution, the tailing end of the preceding rolled plate is
raised higher than the leading end of the succeeding rolled plate by the
tailing end
pinch rollers and after one surface to be joined is machined and is lowered,
one surface
is joined to the other surface of the leading end of the succeeding rolled
plate. The
centering operation of the preceding rolled plate is carried out with the
unmachined
tailing end of the preceding rolled plate raised and after the center line of
the rolled
plate is aligned with the center line of the joining apparatus in the rolling
direction,
the machining is carried out and then the tailing end of the preceding rolled
plate is
lowered to join one surface of the tailing end of the preceding rolled plate
to the other
surface of the leading end of the succeeding rolled plate. At that time, the
centering
can be made again to align positively the center lines of the rolled plates.
Since the
tailing end centering apparatus has an elevating apparatus, the centering can
be made
twice in this manner.
To attain the second object, according to the present invention, there is
provided a cutter cooling apparatus of a rolled plate joining apparatus for
joining
rolled plates after cutting the rolled plates by moving, horizontally in the
width
direction of the rolled plates, a cutter that is fitted to the extremity of a
slant shaft and
is rotated, wherein said cutter has a plurality of cutter tips (e.g., made of
a cemented
carbide produced by sintering WC (tungsten carbide), a major component,
together
with Co (cobalt)) on the surfaces and is abutted on and fixed to a flange
section
provided to said shaft by putting from the extremity of the shaft, a supply
ring is fitted
to form an annular space behind said flange section between it and the outer
circumferential surface of said shaft, said shaft is provided with a supply
passage
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passing through the inside of said shaft from said annular space to
communicate with
a contact surface of said flange section in contact with said cutter, said
cutter is
provided with cooling passages in communication with said supply passage and
extending to said cutter tips, and a coolant is supplied from the outside into
said
annular space to cool said cutter tips from the inner surfaces.
In the above-described cutter cooling apparatus of a rolled plate joining
apparatus, the cutter tips are brought in contact with a coolant (a cooling
non-oxidizing
liquid or cooling inert gas) not from the outside of the high-temperature
atmosphere
to which the cutter is exposed but from the inside. That is, the coolant can
reach the
lo inner surfaces (the surfaces where the connection is made) of the cutter
tips through
the supply passage and the cooling passages from the annular space of the
supply ring.
The coolant reached the inner surfaces of the cutter tips leaks outside from
their gaps
to form streams. Therefore, a fresh coolant can be supplied to the cutter tips
all the
time and therefore the cooling can be carried out efficiently.
Further, according to the present invention, there is provided a cutter ,
cooling apparatus of a rolled plate joining apparatus for joining rolled
plates after
cutting the rolled plates by moving, horizontally in the width direction of
the rolled
plates, a cutter that is fitted to the extremity of a slant shaft and is
rotated, wherein a
cover having opening sections at positions corresponding to the position of
said cutter
2o is provided on one or each of the opposite sides of said shaft, a cooling
pipe for
supplying a coolant is supported outside of said cover, cooling nozzles
directed to said
opening sections from said cooling pipe are provided, and a coolant is jetted
from said
cooling nozzles to said cutter to cool said cutter.
The above-described present cutter cooling apparatus of a rolled plate
joining apparatus jets a coolant (a cooling non-oxidizing liquid or cooling
inert gas)
from the outside of the cutter to carry out the cooling. That is, a cover that
supports a
cooling pipe and cooling nozzles and screens out a high-temperature atmosphere
is
provided and the coolant is jetted from the openings thereof to the surfaces
of the
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CA 02541938 1997-11-12
cutter tips. Therefore, while the temperature of the coolant is kept low, it
can be
supplied to the cutter to effect the cooling efficiently.
Further, according to the present invention, there is provided a cutter
cooling apparatus of a rolled plate joining apparatus for joining rolled
plates after
cutting the rolled plates by moving, horizontally in the width direction of
the rolled
plates, a cutter that is fitted to the extremity of a slant shaft and is
rotated, wherein said
cutter has a plurality of cutter tips on the surfaces and is abutted on and
fixed to a
flange section provided to said shaft by putting from the extremity of the
shaft, a
supply ring is fitted to form an annular space behind said flange section
between it and
l0 the outer circumferential surface of the shaft, said shaft is provided with
a supply
passage passing from said annular space through the inside of said shaft to
communicate with a contact surface of said flange section in contact with said
cutter,
said cutter is provided with cooling passages in communication with said
supply
passage and extending to said cutter tips, a cover having opening sections at
positions
corresponding to the position of said cutter is provided on one or each of the
opposite
sides of said shaft, a cooling pipe for supplying a coolant is supported
outside of said
cover, a supply pipe for supplying a coolant from said cooling pipe into said
annular
space is connected to said supply ring, cooling nozzles directed to said
opening sections
from said cooling pipe are provided, and a coolant from said cooling passage
is brought
2o in contact with the inner surfaces of said cutter tips and is jetted from
said cooling
nozzles to said cutter tips to cool said cutter tips from the surfaces and the
undersurfaces.
The above-described present cutter cooling apparatus of a rolled plate
joining apparatus cools cutter tips from the surfaces and the undersurfaces
thereof.
That is, internal cooling by supplying a coolant (a cooling non-oxidizing
liquid or
cooling inert gas) to the inner surfaces of cutter tips through the supply
ring (annular
space), the supply passage, and the cooling passages through a cooling pipe
and
external cooling by jetting the coolant supplied from the cooling pipe to the
surfaces of
CA 02541938 1997-11-12
the cutter tips from cooling nozzles can be carried out simultaneously.
Accordingly,
the cutter (particularly the cutter tips) can be efficiently cooled.
To attain the third object, according to the present invention, there is
provided a roiled plate joining apparatus for joining rolled plates by cutting
one
surface of the tailing end of a preceding rolled plate and the other surface
of the
leading end of a succeeding rolled plate while traveling in the width
direction and by
overlapping the resulting cut surfaces to be joined, comprising machining
apparatuses
each having a cutter for cutting one surface of the tailing end and the other
surface of
the leading end, a traversing apparatus for running said machining apparatuses
in the
1o plate width direction to move said machining apparatuses to waiting
positions outside
of the plate width, and cutter cooling apparatuses provided in said waiting
positions
for cooling said cutters.
By this constitution, the joining of rolled plates is carried out with an
interval between the joining operations, after the cutting of the surfaces to
be joined,
the machining apparatus waits in the waiting position that is outside of the
plate
width, during that waiting the cutter is cooled by the cutter cooling
apparatus, so that
the increase in temperature during the cutting can be lowered and the life of
the cutter
tips can be prolonged.
Further, according to the present invention, there is provided a rolled plate
joining apparatus for joining rolled plates by cutting one surface of the
tailing end of a
preceding rolled plate and the other surface of the leading end of a
succeeding rolled
plate while traveling in the width direction and by overlapping the resulting
cut
surfaces to be joined, comprising machining apparatuses each having a cutter
for
cutting one surface of the tailing end and the other surface of the leading
end, a
traversing apparatus for running said machining apparatuses in the plate width
direction to move said machining apparatuses to waiting positions outside of
the plate
width, and applying apparatuses provided in said waiting positions for
applying an
abrasion preventive agent to said cutters.
I1
' CA 02541938 1997-11-12 __
By this constitution, the joining of rolled plates is carried out with an
interval between the joining operations, after the cutting of the surfaces to
be joined,
the machining apparatus waits in the waiting position that is outside of the
plate
width, during that waiting an abrasion preventive agent can be applied to the
cutter
tips to reduce the abrasion of the cutter tips.
Further, according to the present invention, there is provided a rolled plate
joining apparatus for joining rolled plates by cutting one surface of the
tailing end of a
preceding rolled plate and the other surface of the leading end of a
succeeding rolled
plate while traveling in the width direction and by overlapping the resulting
cut
surfaces to be joined, comprising machining apparatuses each having a cutter
for
cutting one surface of the tailing end and the other surface of the leading
end, a
traversing apparatus for running said machining apparatuses in the plate width
direction to move said machining apparatuses to waiting positions outside of
the plate
width, and replacing apparatuses provided in said waiting positions for
replacing said
cutters, wherein at least two machining apparatuses wait in said waiting
positions.
By this constitution, if the cutter is damaged during the cutting of the
surfaced to be joined, the particular machining apparatus is moved to the
waiting
position and is replaced with the machining apparatus waiting in the waiting
position,
so that the joining operation can be resumed quickly. Further, at the waiting
position,
the cutter whose cutter tips have been damaged can be replaced.
To attain the fourth object, according to the present invention, there is
provided a continuous hot rolling apparatus, comprising a sizing press for
forcing
down a rolled plate in the width direction supplied from a heating furnace to
press the
rolled plate to have a prescribed width, roughing mills for rolling said
pressed rolled
plate, a winding/unwinding machine for winding and unwinding the rolled plate
rolled by said roughing mills, a crop shear for shearing the leading end and
the tailing
end of the rolled plate that has been unwound, an running joining machine that
can
travel at the conveying speed of the unwound rolled plate for joining the
tailing end
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CA 02541938 1997-11-12
of the preceding rolled plate and the leading end of the succeeding rolled
plate that
have been sheared by said crop shear, a finishing mill for carrying out finish
rolling of
the joined rolled plates, a winding machine for winding the rolled plate that
has been
subjected to finish rolling, and a cutting machine positioned on the entrance
side of
said winding machine for cutting the rolled plate in accordance with the wound
length.
By the above constitution, since the sizing press is forced down in the plate
width by a press, the ability of adjusting the plate width is large, and
therefore if the
number of the types of the widths of the slabs is small, slabs having various
widths can
l0 be made. Thus, by making the widths of slabs less varied, the operation of
varying the
width of the slab on the side of the continuous casting apparatus is made less
often and
therefore the productivity is improved. By providing the winding / unwinding
machine after the roughing mills, the rough rolling line is shortened, and by
winding
the rolled plates into a coil, the effect of keeping temperature prevents the
rolled plates
to be supplied to the finishing mill from being cooled. The leading end and
the
tailing end of the rolled plates are severed by the crop shear suitably for
joining and are
then joined by the joining machine, and the strip after the. finish rolling is
suitably
sheared by the shear on its exit side and is wound by the winding machines
successively, so that the continuous rolling becomes possible to improve the
productivity.
According to a preferred embodiment of the present invention, the above
finishing mill comprises a plurality of finishing mills and an edge forming
machine
having vertical rolls provided on the opposite sides of the rolled plate is
placed at at
least one position out of positions on the entrance sides of said finishing
mills.
By this constitution, a bulge at joined sections joined by the joining machine
and edge drops are formed by the edge forming machine and therefore the
precision of
the plate width and the precision of the plate thickness can be improved.
Further,
since the edge forming machine carries out the forming by vertical rolls,
members that
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CA 02541938 1997-11-12
are not used as proper products as in the case of a forming machine for
cutting
defective parts are not produced, and therefore the yield of the material is
improved.
Further, the above running joining machine is preferably a reducing flame
pressure welding type running joining machine wherein the tailing end of a
preceding
rolled plate and the leading end of a succeeding rolled plate are overlapped
and the
surfaces to be joined are pressure-welded with them covered with reducing
flames.
By this constitution, since the surfaces to be joined are covered with
reducing flames, the surfaces to be joined can be prevented from being
oxidized and a
good joined connection can be obtained. Since the joining is carried out by
pressure
l0 welding, the joining can be carried out in a short period of time and the
length along
which the joining machine travels together with the rolled plates during the
joining
can be shortened. As a result, the rolling line is also shortened.
The above and other objects and advantageous features of the present
invention will be made apparent from the following description made with
reference
to the accompanying drawings, in which like reference characters designate the
same
or similar parts throughout the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a view showing the constitution of a conventional pressure welding
joining apparatus.
Fig. 2 is views showing a partial constitution of a conventional rolled plate
joining apparatus.
Fig. 3 is a view showing the constitution of a conventional hot rolling plant.
Fig. 4 is a view showing an example wherein the centerlines of a preceding
rolled plate and a succeeding rolled plate are not aligned with each other.
Fig. 5 is a view showing other example wherein the center lines of a
preceding rolled plate and a succeeding rolled plate are not aligned with each
other.
Fig. 6 is a view showing a bulge at joined parts.
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Fig. 7 is a view showing edge drops formed at width ends of a plate.
Fig. 8 is a view showing the whole constitution of the rolled plate joining
apparatus according to the present invention.
Fig. 9 is a view showing the arrangement of guide plates taken in the
direction of the arrows X and X of Fig. 8.
Fig. 10 is a view showing the constitution of a tailing end centering
apparatus taken in the directions of the arrows Y and Y of Fig. 9.
Fig. 11 is a view showing the constitution of a leading end centering
apparatus taken in the directions of the arrows Z and Z of Fig. 9.
i0 Fig. 12 is a side sectional view showing the cutter cooling apparatus of
the
rolled plate joining apparatus of the present invention.
Fig. 13 is a side sectional view showing another embodiment of the cutter
cooling apparatus of the rolled plate joining apparatus of the present
invention.
Fig. 14. is a view taken in the direction of the arrow A of Fig. 13.
Fig. 15 is a view showing a partial constitution of the rolled plate joining
apparatus according to the present invention.
Fig. 16 is a view taken in the direction of the arrows X and X of Fig.15.
Fig. 17 is a view taken in the direction of the arrows Y and Y of Fig.16.
Fig. 18 is a view taken in the direction of the arrows Z and Z of Fig. 17.
Fig. 19 is a side view showing the whole constitution of the continuous hot
rolling apparatus according to the present invention.
Fig. 20 is a view showing the constitution of an edge forming machine.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinbelow, embodiments of the present invention are described by
reference to the drawings. In the drawings, like numerals designate like
parts.
Fig. 8 is a side view showing a first embodiment of the present invention.
In this figure, the rolled plate joining apparatus 20 of the present invention
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comprises a truck 22 that travels in the rolling direction shown by an arrow,
tailing
end pinch rolls 24 that are mounted on the truck 22 and can be moved
vertically with
the tailing end of a preceding rolled plate 1 pinched horizontally, leading
end pinch
rolls 26 that are mounted on the truck 22 and can pinch horizontally the
leading end
of a succeeding rolled plate 2, machining apparatuses 28 for cutting the
undersurface of
the tailing end of the preceding rolled plate 1 and the upper surface of the
leading end
of the succeeding rolled plate 2, reducing flame burners 30a and 30b for
keeping the
surfaces to be machined in a reducing atmosphere, and a pressure welding
apparatus
32 for joining the preceding rolled plate 1 and the succeeding rolled plate 2
with the
1o machined surfaces of the preceding rolled plate 1 and the succeeding rolled
plate 2
overlapped and reduced approximately to the thickness of the rolled plates 1
and 2.
The above constitution is the same as that of the conventional one shown
in Fig. 1. The rolled plate joining apparatus 20 of the present invention is
further
provided with a tailing end centering apparatus 40 between the tailing end
pinch rolls
24 and the pressure welding apparatus 32 and a leading end centering apparatus
42
between the pressure welding apparatus 32 and the leading end pinch rolls 26.
An elevating cylinder 24a attached to the side surface of a frame 34 of the
pressure welding apparatus 32 raises or lowers the tailing end pinch rolls 24
between a
machining level H where the undersurface of the tailing end of the preceding
rolled
2o plate 1 is brought in contact with the upper surface of the below-described
cutter 19a
and a pressure welding level L where the tailing end of the preceding rolled
plate 1 is
kept approximately at the same level as that of the leading end of the
succeeding rolled
plate 2. The tailing end pinch rolls 24 comprises an upper and lo~Ner rolls
and the
upper roll is raised or lowered by a driving apparatus (not shown). When the
upper
roll is lowered, the tailing end of the preceding rolled plate 1 is pinched
horizontally,
while when the upper roll is raised, the lower roll acts as a guide roll of
the rolled
plate. Thus, while the preceding rolled plate 1 is held at the machining level
H by the
elevating cylinder 24a with the tailing end of the preceding rolled plate 1
supported
16
CA 02541938 1997-11-12
horizontally by the tailing end pinch rolls 24, the undersurface of the
tailing end of the
preceding rolled plate 1 and the upper surface of the leading end of the
succeeding
rolled plate 2 can be cut by the cutter 19a, then the tailing end pinch rolls
24 are
lowered to place the surfaces of the preceding rolled plate 1 and the
succeeding rolled
plate 2 to be machined one over the other with the tailing end of the
preceding rolled
plate 1 supported horizontally and they can be pressed and joined by the
pressure
welding apparatus 32.
The leading end pinch roll 2~ comprises an upper roll and a lower roll and
the upper roll is moved vertically by a driving apparatus (not sho~n~n). The
upper roll
1o is lowered to pinch the leading end of the succeeding rolled plate 2
horizontally and
when the upper roll is raised, the lower roll acts as a guide roll of the
rolled plate.
Guide rollers 25 are arranged stepwise in front of the tailing end pinch rolls
24, so that the rolled plate 1 assumes a posture of a gentle curve. A~
displacement
roller 25a is moved vertically in conformity with the elevation of the tailing
end pinch
rolls 24 and when the tailing end pinch rolls 24 are at the pressure welding
level L, the
displacement roller 25a is displaced so that the rolled plate 1 may be placed
horizontally. Before and after the leading end pinch rolls 26 are also
arranged guide
rollers 27, so that the rolled plate 2 assumes a posture of a gentle curve.
The machining apparatus 28 comprises a cylindrical cutter 19a that is rotated
2o around the axis extending in the direction of the width of the rolled
plates 1, 2, an arm
19b for swinging slantly the cutter 19a, and a reciprocating machine
(hydraulic
cylinder) 19c for moving back and forth the cutter 19a slantly to the rolling
direction.
The cutter 19a is attached to the extremity of the arm 19b and performs
rotating cutting
by a rotating driving apparatus (not shown). The cutter 19a cuts the
undersurface of
the tailing end of the preceding rolled plate 1 and the upper surface of the
leading end
of the succeeding rolled plate 2 at the machining position of the arm 19b
shown in
solid line in Fig. 8 by the action of the arm 19b and the reciprocating
apparatus 19c and
after the machining, the arm 19b is retracted to the position shown in phantom
line.
17
CA 02541938 1997-11-12
The reducing flame burners 30a, 30b burn a combustible gas, such as coke
oven gas, LPG, and LNG, with oxygen in an amount less than the amount to cause
complete combustion thereby forming reducing flames and blow the flames to the
surfaces to be machined to prevent the surfaces from being oxidized. The
reducing
flame burner 30a is attached to the tailing end pinch rolls 24 and the
reducing flame
burner 30b is attached to the truck 22 through a support (not shown). The
reducing
flame burners 30a, 30b blow reducing gas toward the surfaces to be machined of
the
undersurface of the tailing end of the preceding rolled plate 1 and the upper
surface of
the leading end of the succeeding rolled plate 2 to keep them in a reducing
atmosphere
to to prevent the cut surfaces from being oxidized and also to prevent the
temperature of
the cut surfaces from being lowered.
In the pressure welding apparatus 32, several (in this case three) hydraulic
cylinders 33 are used. The hydraulic cylinders 33 are supported by the frame
34 and
the frame 34 is supported by props 35. The lower parts of the props 35 are
fixed to the
truck 22. The rod extremities of the hydraulic cylinders 33 are fixed to an
upper mold
apparatus 36 and below the upper mold apparatus 36, a lower mold apparatus 37
for
bearing the compression load from the hydraulic cylinders 33 is fixed to the
truck 22.
The upper mold apparatus 36 is driven down by the hydraulic cylinders 33 to
press the
upper surface of the preceding rolled plate 1 and the undersurface of the
succeeding
rolled plate 2 to forcibly join the rolled plates 1, 2 to approximately the
thickness of the
rolled plates 1, 2.
The truck 22 has a plurality of wheels 23 and can travel on rails 15 extending
in the rolling direction. B indicates the rolling level of the rolling
apparatus and the
rolled plate 1 or 2 is supported on a plurality of rollers 16 and is moved in
the rolling
direction. The rails 15 are arranged outside of the rollers 16 and allow the
truck 22 to .
travel in a position higher than the rails 15 with the pressure welding level
L being
higher than the rolling level B. Slanted guides 38, 39 are provided that can
be swung
up and down to guide the rolled plate 1 from the rolling level B of the
rolling
18
CA 02541938 1997-11-12 ,
apparatus to the leading end pinch rolls 26 and from the tailing end pinch
rolls 24 to
the rolling level B and are swung by hydraulic cylinders, respectively. By
positioning
the slanted guides 38, 39 in the positions shown in phantom line, an existing
rolling
apparatus can be operated.
Fig. 9 is a view taken in the direction of the arrows X and X of Fig. 8,
showing the arrangement of guide plates for aligning the center lines of the
rolled
plates 1, 2. The guide plates 43 are parallel with the center line 41 in the
rolling
direction of the joining apparatus 20 and the opposed guide plates 43 can be
moved in
the direction of the width of the rolled plates 1, 2 by equal distances from
the center
line 41.
Fig. 10 shows the constitution of the tailing end centering apparatus 40
shown in the direction of the arrows Y and Y of Fig. 9. A pinion 47 is
positioned
between a lower rack plate 44 having a rack 46 on its upper surface and an
upper rack
plate 45 having a rack 46 on its undersurface and is meshed with the racks 46
of the
rack plates 44, 45. The guide plates 43 are fixed to the undersurfaces of the
rack plates
44, 45 in the rolling direction and the distance between the guide plates 43
is of the
order of the width of a standard rolled plate. The lower rack plate 44 and the
upper
rack plate 45 can be retracted or extended in the direction of the width of
the rolled
plates 1, 2 by a rack plate driving apparatus 48. Although the shown rack
plate driving
apparatus 48 uses a hydraulic cylinder, it may use an apparatus for rotating
the pinion
47.
The forward end and the rearward end of the upper and lower rack plates 44,
45 in the rolling direction are provided with end plates 49 that are
integrally joined.
The end plates 49 are provided with horizontal guide grooves 50 for guiding
the
movement of the upper and lower rack plates 44, 45 in the plate width
direction. A
support frame 51 in the shape of a gate attached to a truck 12 is provided
outside of the
end plates 49 and restricts the movement of the end plates 49 only to the
vertical
movement. The end plates 49 are moved vertically by elevating cylinders 52
attached
I9
CA 02541938 1997-11-12 __
to the support frame 51. The tailing end centering apparatus 40 is set in such
that the
guide plates 43 have equal distances from the center line 41 of the joining
apparatus 20
in the rolling direction. By retracting or extending the upper and lower rack
plates 44,
45 in the direction of the width of the rolled plate by the rack plate driving
apparatus
s 48, the center line of the preceding rolled plate 1 can be aligned with the
center line of
the joining apparatus 20 in the rolling direction. Further, by operating the
elevating
cylinders 52, the guide plates 43 can be moved vertically.
Fig. 11 is a view taken in the direction of the arrows Z and Z of Fig. 9,
showing the constitution of the leading end centering apparatus 42. While the
tailing
1o end centering apparatus 40 is provided on the upper side of the rolled
plate 1, the
leading end centering apparatus 42 is provided on the lower side of the rolled
plate 2.
However, the basic constitution of the latter for centering is the same as the
former.
That is, a pinion 47 is arranged between a lower rack plate 44 having a rack
46 on its
upper surface and an upper rack plate 45 having a rack 46 on its undersurface
and is
15 meshed with the racks 46 of the rack plates 44, 45. The guide plates 43 are
fixed to the
upper surfaces of the rack plates 44, 45 in the rolling direction and the
distance between
the guide plates 43 is of the order of the ~Nidth of the standard rolled
plate. The lower
rack plate 44 and the upper rack plate 45 can be retracted or extended in the
direction of
the width of the rolled plates 1, 2 by a rack plate driving apparatus 48.
Although the
2o shown rack plate driving apparatus 48 uses a hydraulic cylinder, it may use
an
apparatus for rotating the pinion 47. Further, the leading end centering
apparatus 42
is set in such that the guide plates 43 have equal distances from the center
line 41 of
the joining apparatus 20 in the rolling direction. By retracting or extending
the upper
and lower rack plates 44, 45 in the direction of the width of the rolled plate
by the rack
25 plate driving apparatus 48, the center line of the succeeding rolled plate
2 can be
aligned with the center line of the joining apparatus 20 in the rolling
direction. Thus,
by aligning the center line of the preceding rolled plate 1 with the center
line 41 of the
joining apparatus 20 in the rolling direction and aligning the center line of
the
CA 02541938 1997-11-12
succeeding rolled plate 2 with the center line 41 of the joining apparatus 20,
the center
lines of the preceding rolled plate 1 and the succeeding rolled plate 2 can be
aligned
with each other.
As is apparent from the above description, by providing the tailing end
centering apparatus and the leading end centering apparatus, the present
invention
allows the center lines of the preceding rolled plate and the succeeding
rolled plate to
be aligned with each other thereby making precise joining possible and thus by
securing the straightness of the rolled plates positively, the occurrence of a
camber or a
meander at the time of the finish rolling can be prevented. Thereby the time
of
to stoppage of the line can be reduced to improve the productivity.
Fig. 12 is a side section of the rolled plate joining apparatus of the present
invention, showing a second embodiment. The rolled plate joining apparatus of
the
present invention shown in this figure is a rolled plate joining apparatus
equipped
with a cutter cooling apparatus having a cutting apparatus 63 for cutting a
rolled plate
by moving a conical cutter 62, which is put on the extremity of a slant shaft
61 and is
rotated, horizontally in the direction of the width of the rolled plate (see
Fig. 2). The
conical cutter 62 has a plurality of cutter tips 62a on its truncated conical
surfaces and is
fixed with it abutted on a flange section 64 provided to the shaft- 61 by
putting from the
extremity of the shaft 61. A supply ring 65 is fitted to form an annular space
65a
behind a flange section 64 between it and the outer circumferential surface of
the shaft
61. Further, the shaft 61 is provided with a supply passage 66 through the
inside of the
shaft 61 from the annular space 65a to communicate with a contact surface 64a
of the
flange section 64 in contact with the conical cutter 62. The conical cutter 62
is also
provided with cooling passages 67 that are in communication with the supply
passage
66 and extend to the cutter tips 62a. In this constitution, a coolant (a
cooling non-
oxidizing liquid or cooling inert gas) is supplied from the outside into the
annular
space 65a to cool the cutter tips 62a from the inside.
In passing, in this embodiment, a case wherein as a cooling inert gas,
21
CA 02541938 1997-11-12
nitrogen gas is used is described.
The supply ring 65 has a flange section 65b at one end and is cylindrical and
its inner circumferential surface has an annular groove. The annular space 65a
is
formed between this groove and the shaft 61. Bolts 68 are threaded into the
flange
section 65b to fix the supply ring 65 to a traversing table 15 of a traverse
moving
apparatus (see Fig. 2). High-pressure gas seals 69 are provided on opposite
sides of the
groove that forms the annular space 65a to keep the airtightness between it
and the
shaft 61. A nitrogen gas supply port 58 is provided to communicate with the
anr_~tlar
space 65a.
The supply passage 66 is composed of a main supply passage 66a formed in
the central part of the shaft 61 and distribution supply passages 66b formed
in the
flange 64 and is, for example, formed as follows. First the main supply
passage 66a is
drilled in the central part of the shaft 61 from the extremity (on the side of
the conical
cutter 62) to the position of the annular space 65a and further holes are
radially formed
to communicate with the annular space 65a. In passing the extremity of the
main
supply passage 66a is made airtight when it is in use. Then the distribution
supply
passages 66b are drilled radially from the flange section 64 to the main
supply passage
66a and a plurality of circumferentially arranged holes are drilled axially
from the side
of the contact surface 64a in contact ~.vith the conical cutter 62 to
communicate with
them. By way of parenthesis, plugs 59 are put into ends of the radially
drilled holes to
make them airtight.
The foregoing cooling passages 67 are formed in a barrel section 62b of the
conical cutter 62 so that they are completely in communication with the above-
described distribution passages 66b. The cooling passages 67 are composed of
main
cooling passages 67a in communication with the distribution supply passages
66b and
distribution cooling passages 67b distributed from the main cooling passages
67a to the
cutter tips 62a. The main cooling passages 67a are formed by drilling axially
a plurality
of circumferentially arranged holes in the barrel 626 of the conical cutter 62
from the
22
CA 02541938 1997-11-12
side of the contact surface in contact with the flange section 64. The
distribution
cooling passages 67b are formed to extend from the main cooling passages 67a
to
recesses in which the cutter tips 62a are attached. Additionally stated,
although not
shown in the figures, the joint section of the flange section 64 and the
conical cutter 62
is provided with an O-ring to keep the seam between the supply passage 66 and
the
cooling passages 67 sealed.
In accordance with the cutter cooling apparatus of the rolled plate joining
apparatus of the present invention, by supplying nitrogen gas to the nitrogen
gas
supply port 58 of the supply ring 65, the nitrogen gas can reach the inner
surfaces of the
l0 cutter tips 62a (the surfaces on the side of the connection) via the supply
passage 66 of
the shaft 61 that is being rotated and the cooling passages 67 from the
annular space
65a. The nitrogen gas reached the inner surfaces of the cutter tips 62a leaks
out from
their gaps to form streams of the nitrogen gas. Accordingly, fresh nitrogen
gas can be
supplied to the cutter tips 62a all the time and therefore the cooling can be
earned out
efficiently.
Figs. 13 and 14 are views showing other embodiment of the cutter cooling
apparatus of the rolled plate joining apparatus of the present invention. Fig.
13 is a
side view thereof and Fig. 14 is a view taken in the direction of the arrow A
of Fig. 13.
The rolled plate joining apparatus of the present invention shown in these
figures is a
rolled plate joining apparatus equipped with a cutting apparatus 63 for
cutting a rolled
plate by moving a conical cutter 62, which is put on the extremity of a slant
shaft 61
and is rotated, horizontally in the direction of the width of the rolled plate
(see Fig. 2).
The conical cutter 62 has a plurality of cutter tips 62a on its truncated
conical surfaces
and is fixed with it abutted on a flange section 64 provided to the shaft 61
by putting
from the extremity of the shaft 61. A supply ring 65 is fitted to form an
annular space
65a behind the flange section 64 between it and the outer circumferential
surface of the
shaft 61. Further, the shaft 61 is provided with a supply passage 66 through
the inside
of the shaft 61 from the annular space 65a to communicate with a contact
surface 64a of
23
CA 02541938 1997-11-12
the flange section 64 in contact with the conical cutter 62. The conical
cutter 62 is also
provided with cooling passages 67 that are in communication with the supply
passage
66 and extends- to the cutter tips 62a. The above constitution is the same as
that of the
embodiment shown in Fig. 12.
In Figs. 13 and 14, on the opposite sides of the shaft 61, there are provided
covers 72 having opening sections 72a at positions corresponding to the
positions of
the supply ring 65 and the cutter tips 62a. Further, a cooling pipe 73 for
supplying a
coolant (a cooling non-oxidizing liquid or cooling inert gas) is supported on
the
outside of the cover 72 and a supply pipe 74 for supplying the coolant from
the cooling
pipe 73 into the annular space 62a is connected to the supply ring 65.
Further, there
are provided cooling nozzles 75 directed to the opening sections 72a from the
cooling
pipe 73. In this constitution, the coolant is brought in contact with the
inner surfaces
of the cutter tips 62a from the cooling passages 67 and also is jetted at the
cutter tips 62a
from the cooling nozzles 75, so that the cutter tips 62a are cooled from the
outside and
the inside. By way of parenthesis, the supply ring 65, the supply passage 66,
and the
cooling passages 67 are the same as those of the embodiment shown in Fig. 12
and
therefore the description is omitted. In this embodiment, also, a case wherein
as a
cooling inert gas, nitrogen gas is used is described.
The covers 72 are provided on the opposite sides of the shaft 61 as is shown
in Fig. 14 and one end is fixed to the traversing table 15 by bolts 76 and the
other end is
connected to a connecting member 77 and is fixed by bolts 78. A nipple 73c of
the
cooling pipe 73 is supported outside of the covers 72 by support members 79
and the
cooling nozzles 75 are connected to the nipple 73c through T-shaped pipe
joints 73a or
an L-shaped pipe joint 73b. Further, in this embodiment, nitrogen gas is
supplied
from the cooling pipe 73 into the annular space 65a of the supply ring 65
through the
T-shaped pipe joints 73a. Therefore, one supply source can be used for
internal
cooling and external cooling. If the internal cooling and the external cooling
are
carned out by using different coolants, separate supply sources may be
provided.
24
CA 02541938 1997-11-12
Parenthetically, the cooling pipe 73 may be supported by the cover 72 provided
only on
one side of the shaft 61.
According to the cutter cooling apparatus of the rolled plate joining
apparatus of the present invention described above, internal cooling by
supplying
nitrogen gas from the cooling pipe 73 to the inner surfaces of the cutter tips
62a
through the supply ring 65 (annular space b5a), the supply passage 66, and the
cooling
passages 67, and external cooling by jetting nitrogen gas supplied from the
cooling pipe
73 onto the surfaces of the cutter tips 62a from the cooling nozzles 75 can be
carried out
simultaneously to cool the cutter tips 62a efficiently.
to Although not shown, the cutter cooling apparatus of the rolled plate
joining
apparatus may be constructed in such that only external cooling is carried out
by jetting
nitrogen gas supplied from the cooling pipe 73 onto the surfaces of the cutter
tips 62a
from the cooling nozzles 75.
As is described above, according to the cutter cooling apparatus of the rolled
i5 plate joining apparatus of the present invention described above, the
cutter
(particularly cutter tips) can be cooled and the life thereof can be prolonged
considerably. Further, although internal cooling only or external cooling only
can be
carried out for the cooling, by carrying out internal cooling and external,
cooling
simultaneously, the cutter tips can be cooled efficiently.
2o Fig. 15 is a view of a partial constitution of a third embodiment of the
rolled
plate joining apparatus of the present invention, showing a cutting apparatus
and
apparatuses around it. Fig. 16 is a view taken in the direction of the arrows
X and X of
Fig. 15, showing the cutting apparatuses in the waiting positions, Fig. 17 is
a view
taken in the direction of the arrows Y and Y of Fig. 16, showing the
traversing
25 apparatuses, and Fig. 18 is a view taken in the direction of the arrows Z
and Z of Fig.
17, showing the apparatuses for replacing the cutters.
The cutting apparatus 11 comprises a cutter 13, a cutter shaft 11a having the
cutter 13 detachably to its extremity, a shaft support section 11b for
rotatably supporting
CA 02541938 1997-11-12
the cutter shaft 11a, and a shaft driving apparatus 11c for rotating the
cutter shaft 11a.
Waiting positions 80 wherein the cutting apparatuses 11 wait are provided on
the
opposite sides of the width of the plate. Two parallel guide rods 82 extending
to the
waiting positions 80 are provided and there are provided guide blocks 83
slidably fitted
to the guide rods 82 and fixed to the shaft support sections 11b and a
traversing
cylinder 84 for traversing the guide block 83 along the guide rods 82.
Further, in the waiting positions 80, there are provided cooling agent
nozzles 86 for discharging a cooling agent and abrasion preventive agent
nozzles 87 for
applying an abrasion preventive agent. The cooling agent nozzles 86 are
connected to
l0 an air source or a liquid nitrogen tank (not shown) to blow air or
vaporized low-
temperature nitrogen to the cutters 84. The abrasion preventive agent nozzles
87 are
connected to an abrasion preventive agent supply apparatus {not shown) to
apply an
abrasion preventive agent to the cutter tips 13c of the cutter 13. As the
abrasion
preventive agent, a paste comprising a lubricant, such as molybdenum disulfide
(MoS2), graphite (C), and lead oxide (Pb0), and a binder, such as water glass
and starch,
is applied. The cooling agent nozzle 86 and the abrasion preventive agent
nozzle 87
for the cooling of and the application to the cutter tips are illustrated
integrally, but
they may be separately provided.
Further, in the waiting positions 80, there are provided replacing
apparatuses 88 for replacing cutters over the positions where the cutters 13
wait. Each
of the replacing apparatuses 88 has a crane for hoisting or lowering the
cutter 13.
The operation of the cutting apparatus constructed as described above and
apparatuses around it are now described.
The joining of the rolled plates 1, 2 is carried out with an approximately
constant interval in the same lot and the joining time is within several tens
seconds
(generally within 20 seconds). At the time of joining, the cutting apparatus
1I is
traversed by the traversing cylinder 84 from one end of the plate width to the
other
end between the undersurface of the tailing end of the preceding rolled plate
1 and the
26
CA 02541938 1997-11-12
upper surface of the leading end of tile succeeding rolled plate 2 while the
cutter 13 is
rotated by the shaft driving apparatus llc to perform cutting. Since the cut
surfaces
are covered with reducing flames from reduction keeping apparatuses 12 and the
cutting generates heat, the temperature of the cutter 13 during the cutting
becomes
very high. After the completion of the cutting, it waits at the waiting
position 80 for
the next joining. If the cutter 13 is damaged during the cutting, the cutting
apparatus
11 is moved immediately to the waiting position 80, and other cutting
apparatus 11
waiting in other waiting position 80 is moved to the cutting position to
resume the
cutting.
In the waiting position 80, air or vaporized low-temperature nitrogen gas is
discharged from the cooling agent nozzle 86 to cool the cutter 13. During the
cooling,
the cutter 13 is rotated quickly to be cooled uniformly. When the cutter 13 is
cooled to
a prescribed temperature, the cooling is stopped and an abrasion preventive
agent,
such as molybdenum disulfide, from the abrasion preventive agent nozzle 87 is
applied to the cutter tips 13c. Further, in the case wherein the cutter tips
13c are
damaged or abraded to the limit, the cutter is cooled and replaced with a new
cutter 13
using the replacing apparatus 88.
In this embodiment, one of the cutting apparatuses 11 is provided in one of
the waiting positions 80 on the opposite sides of the plate width and the
other cutting
2o apparatus 11 is provided in the other waiting position 80, but both the
cutting
apparatuses 11 may be provided in one of the waiting positions 80. Also, three
such
cutting apparatuses 11 may be provided with one of them placed in one of the
waiting
positions 80 and with two of them placed in the other waiting position 80. In
this
way, the present invention is not restricted to the embodiment and indeed can
be
modified in various ways without departing from the spirit and scope of the
present
invention.
As is described above, according to the present invention, the life of a
cutter
is prolonged since the cutting is carried out with the cutter cooled by
providing cooling
27
CA 02541938 1997-11-12
apparatuses for cooling cutters in waiting positions. Further, since an
abrasion
preventive agent can be applied to cutter tips in waiting positions, the life
of the cutter
is prolonged. Further, since cutter replacing apparatuses are provided in
waiting
positions, the replacement of a cutter can be carried out easily. Also, since
at least two
machining apparatuses are provided in waiting positions, if one of cutters is
damaged,
it can be immediately replaced.
Fig. 19 is a view sho~n~ing a fourth embodiment of the present invention. In
this figure, 91 indicates a continuous casting machine by which slabs chosen
out of
slabs having a thickness of about 250 mm and predetermined types of slab
widths can
1o be supplied. 92 indicates a heating furnace that heats slabs (rolled
plates) to a
temperature suitable for the succeeding rolling operation. 93 indicates a
sizing press
for pressing slabs with a press in the plate width direction and generally the
pressing to
about 300 mm is possible. When the sizing press 93 was not used, in the
continuous
cutting machine 91, it was required to supply slabs with the width defined
inch by inch
in accordance with the specification. For instance, the slab width had to be
600 mm,
620 mm, and 640 mm, but using the ability of the sizing press 13 of adjusting
the width
by 300 mm, since the width may be 600, 900,1,200, and 1,500 mm, the types of
molds of
the continuous casting machine 91 required for widths can be reduced
considerably
and accordingly the mold replacing operation is reduced considerably to
improve the
productivity.
Roughing mills 94 roll roughly a slab 1 to a thickness suitable for allowing
the resulting rolled plate to be wound by the below-described
winding/unwinding
machine 96 and suitable finish roiling, for example, to a thickness of about
30 mm.
The number of the roughing mills will depend on the thickness of the slab 1
that will
be supplied, and for example if the slab 1 has a thickness of about 250 mm,
two reverse
type roughing mills or 5 or 6 unidirectional roughing mills may be
recommended, and
if the thickness of the slab is increased, the number of the roughing mills is
increased.
Parenthetically, vertical type rolling mills 95 are provided on opposite sides
of each of
28
CA 02541938 1997-11-12
the roughing mills 94 to control the plate width.
The winding/un winding machine 96 is an apparatus that takes up the
rolled plate 1 that has been roughly rolled into a coil and unwinds that coil.
The
winding is carried out without a stem, and the coil is moved to an unwinding
position
and is unwound without a stem or with a stem that is also used for the
movement.
An unwinding machine that uses a stem can also be used. By winding in this
way,
the rough rolling line can be shortened. The formation of a coil requires less
cooling
and can keep a suitable finish rolling temperature. In passing, the windin
g/unwinding machine 96 may be covered with an insulating material.
1o A crop shear 97 is an apparatus for cutting so that the tailing end of a
preceding rolled plate to be joined and the leading end of a succeeding rolled
plate to
be joined may be joined suitably by the below-described reducing flame
pressure
welding type running joining machine 98. The reducing flame pressure welding
type
running joining machine 98 pressure-welds the tailing end of a rolled plate 1
unwound from the preceding coil to the leading end of the rolled plate 1
unwound
from the succeeding coil while the reducing flame pressure welding type
running
joining machine 98 is run at the same speed as that of the rolled plate 1 and
the
surfaces to be joined are prevented from being oxidized by creating a reducing
atmosphere around the surfaces to be joined.
Finishing mills 99 carry out finish rolling of the joined rolled plates 1 to,
for
example, a strip generally having a minimum thickness of about 1.2 mm. The
number of the finishing mills is about 6 to 7 and will be determined by the
finally
finished plate thickness. Edge forming machines 100 are provided on the
entrance
side of some of the finishing mills 99. Generally one edge forming machine is
provided for the first finishing mill and one or two edge forming machines are
provided for the last finishing mill. Each edge forming machine 100 comprises
vertical type rolls that are provided on the opposite sides of the rolled
plate 1 and
forced down in the plate width direction to mold the rolled plate 1 to have a
prescribed
29
CA 02541938 1997-11-12
width to improve the plate width precision and the plate thickness precision.
The
edge forming machines 100 correct a bulge la shown in Fig. 6 to make the width
equal
to the other or decrease the width further to correct edge drops 1b shown in
Fig. 7 to
make the thickness uniform to the ends of the plate width and to cause the
rolled plate
to have a prescribed plate width. The edge forming machine 100 provided on the
entrance side of the first finishing mill 99 adjusts the width of the rolled
plate 1
entering the series of the finishing mills 99 and the edge forming machines
100
provided om the entrance side of the last one or tv~~o finishing mills 99
correct edge
drops 1b produced by the finish rolling to obtain a prescribed plate
thickness.
The rolled plate 1 rolled to the final plate thickness by the finishing mills
99
is wound by a winding machine 102 into a coil. When the coil has a prescribed
diameter, the rolled plate 1 is cut by a cutter 101, which is operated at a
high speed, to
complete the winding. The succeeding rolled plate 1 after the cutting is wound
by
other winding machine 102 to resume the winding. The rolled plates 1 joined by
the
reducing flame pressure welding type running joining machine 98 are
continuously
processed by the finishing mills 99 and the winding machine 102 and thus the
productivity and the yield are improved.
As is shown in Fig. 8, the reducing flame pressure welding type ,running
joining machine 20 is equipped with a truck 22 that travels in the rolling
direction,
tailing end pinch rolls 24 that are mounted on the truck 22 and can be moved
vertically with the tailing end of a preceding rolled plate 1 pinched
horizontally,
leading end pinch rolls 26 that are mounted on the truck 22 and can pinch
horizontally the leading end of a succeeding rolled plate 2, machining
apparatuses 28
for cutting the undersurface of the tailing end of the preceding rolled plate
1 and the
upper surface of the leading end of the succeeding rolled plate 2, reducing
flame
burners 30a and 30b for keeping the surfaces to be machined in a reducing
atmosphere,
and a pressure welding apparatus 32 for joining the preceding rolled plate 1
and the
succeeding rolled plate 2 with the machined surfaces of the preceding rolled
plate 1
CA 02541938 1997-11-12
and the succeeding rolled plate 2 overlapped and reduced approximately to the
thickness of the rolled plates 1 and 2.
Thus, while the preceding rolled plate 1 is held at the machining level H by
the elevating cylinder 24a with the tailing end of the preceding rolled plate
1 supported
horizontally by the tailing end pinch rolls 24, the undersurface of the
tailing end of the
preceding rolled plate 1 and the upper surface of the leading end of the
succeeding
rolled plate 2 can be cut by the cutter 19a, then the tailing end pinch rolls
24 are
lowered to place the surfaces of the preceding rolled plate 1 and the
succeeding rolled
plate 2 to be machined one over the other with the tailing end of the
preceding rolled
to plate 1 supported horizontally and they can be pressed and joined by the
pressure
welding apparatus 32. In passing, during the cutting and pressure-welding, the
atmosphere surrounding the surfaces to be cut is made to be a reducing
atmosphere by
the reducing flame burners 30a, 30b to prevent the surfaces to be cut from
being
oxidized.
Fig. 20 is a view generally showing the edge forming machine 100. The
rolled plate 1 is forced down in the plate width direction by the vertical
type rolls 100a
provided on the opposite sides of the rolled plate 1 to cause the rolled plate
1 to have a
prescribed plate width. The vertical type rolls 100a can be moved in the plate
width
direction by an apparatus (not shown) to cause the plate width to be set to a
prescribed
2o distance.
In the above embodiment, although the slab supplied from the continuous
casting machine 91 has a thickness of about 250 mm, the present invention may
be
applied to thicker slabs, for example, slabs having a thickness of about 1I0
mm. In
that case, the number of roughing mills 94 is increased in conformity with the
thickness of the slab.
As is apparent from the above description, in the present invention, since
the hot rolling line includes a sizing press, a winding/unwinding machine, a
joining
machine, edge forming machines, and a cutting machine, the widths of slabs
supplied
31
CA 02541938 1997-11-12
by a continuous casting machine can be ralade intensive and therefore the
productivity
of the continuous casting machine and the productivity of the hot rolling
plant are
improved. Further, the continuous rolling of strips is made possible, and
therefore
the productivity and the yield are improved. Further, the plate width
precision is
improved by the edge forming machines before or between finishing mills and
edge
drops are made better.
While the present invention has been described in connection with certain
preferred embodiments, it is to be understood that the subject matter
encompassed by
way of the present invention is not to be limited to those specific
embodiments. On
l0 the contrary, it is intended for the subject matter of the invention to
include all
alternatives, modifications and equivalents as can be included within the
spirit and
scope of the following claims.
32
