Note: Descriptions are shown in the official language in which they were submitted.
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METHOD AND APPARATUS FOR WINDING STRIP,
IN PARTICULAR METAL STRIP
The invention relates to an apparatus for winding a strip
of varying thickness, in particular a flat or profiled strip, a
flexibly and/or a profile-rolled metal strip, in particular of
steel, into a coil with a device for applying a deformable material
to the strip being wound.
Above all, the invention concerns the winding of slit
strips. Slit strips are created when elongated material, in
particular wide metallic strip, is pulled off a coil and cut
longitudinally into narrow strips, i.e. split. The thus created
narrow split strips are subsequently wound up on a common mandrel
or wound onto separate respective mandrels. Preferably, composite
coils each containing a number of adjacent split strips are
created. To adjust for deviations in thickness over the width of
the strip, which lead to tapered or angled surfaces in particular
at the edges of the strips, while winding the split strips,
intermediate layers must be inserted into the coils of the split
strips.
Even when winding split strip material onto a continuous
drum with several coaxially adjacent winding coils of longitudinal
machines that are separated from each other by sheet metal disks,
as a consequence of varying strip thickness and coating thickness
more or less tightly wound coils with correspondingly different
strip sagging results. The uneven winding of the coils has a
disadvantageous effect on their appearance, packaging, the
unwinding behavior and the friction between the individual strip
coils. In order to avoid these problems it is known to wind paper
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or cardboard strips of appropriate lengths between the turns of the
split strips. Frequently, this is done in that the paper strip is
manually inserted into the wound section slot between the winding
strip and the coil.
A device is known from DE 80 06 563 [DE 30 09 2001 for
fitting spacer strips into the winding slot of strip material that
is to be wound into coils, where the paper strip is transported in
the direction toward the winding slot by means of a pair of drive
rollers. Here, the supply for the paper strip is designed as a
drum that contains the intermediate paper strip, upstream of whose
strip slot the pair of driving pulleys that are driven by an
electric motor is provided. Upstream of the pair of driving
pulleys a strip separating and perforating device is provided.
This way, the intermediate strip can be projected into the winding
slot at high speed as the result of the pair of driving pulleys
with simultaneous temporary deformation into a stable, air-carried
profile that is open toward the bottom. The intermediate strip
must be deformed by the roof-shaped profiling of the driving
pulleys in such a way that it retains a sufficiently stable shape
that is supported by air that ensures that it can also be shot into
the winding slot across a larger distance of free flight, whereby
in addition to the effect of being borne by air, the effect of
acceleration is also utilized.
The intermediate strips are either removed from a stack
container containing the strips in appropriate lengths and
individually shot into the wound section of the metal strip or
pulled off a supply strip coil and cut into the required lengths.
In EP 0 166 795, a method of winding several split strips
created by longitudinal cutting of linear material onto a joint
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winding mandrel is described, in which the elongated material
deviates in thickness over its width.
The method is characterized in that the split strips are
wound simultaneously into a composite coil with a deformable
elongated intermediate layer of adjacently running split strips
across its width.
Here, the thickness of the intermediate layer is larger
than the deviation of thickness over the width of the elongated
material. During winding of the split strips, as the result of the
exertion of a force onto the respectively uppermost winding
position of the split strips and/or the intermediate layer in the
radial direction of the composite coil, the thicker split strips
are pressed more than the thinner ones into the intermediate layer,
and the split strips are wound by a corresponding deformation of
the intermediate layer into a composite coil with cylindrical
enveloping surface. As per this method, uncoated or coated
metallic strip can be wound as elongated material. Preferably,
paper, mash, plastic, in particular, foam or paper impregnated with
an agent that protects against corrosion is used.
Further, it is also known to not only produce flat metal
strips, but also metal strips whose shape varies in the
longitudinal and/or the transverse direction. In DE 198 31 882 Al,
a method and a rolling system for the production of profiles of any
thickness over the width of a linear rolling stock is described.
The initial material is here deformed almost only in the direction
of width by several rollers that are offset spaced apart other in
the roll direction. The rolls make a correspondingly desired
profiling of the locally targeted deformation possible, the depth
of penetration depending on the control of the respective
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individual small drums or rolls. The starting material is either
iron or a NE material; cold-forming or warm-forming is used.
From DE 199 62 754 [US 6,336,349], a method of flexible
rolling of a metal strip is known. This method is for the
production of flat metal strips that have defined, varying strip
thicknesses over their length. Thus during the roll process the
roll gap is changed in a controlled manner in order to obtain
various strip thicknesses of the metal strip. On the one hand,
this can take place indirectly by changing the deformation
resistance of the material by warming or cooling the metal strip
and the correspondingly changed frame spring of the roll stand
during the roll process.
EP 1 074 317 [US 6,336,350] also concerns a method of
flexible rolling of a metal strip, where the metal strip is guided
during the rolling process through a roll gap formed between two
working rolls and the roll gap is manipulated in a controlled
manner during the roll process in order to achieve various strip
thicknesses over the length of the metal strip. Here, during each
adjustment of the roll gap or directly afterward, the bending lines
of the working rolls are controlled depending on the roll gap that
was selected for flattening the metal strip.
It is the object of the invention to provide a method of
winding a strip, in particular a flat or profiled strip, a flexibly
rolled and/or a profile-rolled metal strip that is improved in such
a way that in a simple manner, an even, at least essentially
cylindrical coil is created.
In accordance with the invention, this object of the
method mentioned is attained in that the device comprises means for
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creating a resilient, in particular elastic, material or a self-
expanding or foamable material and for applying it to the coil.
According to the invention, the necessary materials are
prepared in situ corresponding to the requirements of the strip to
be wound, i.e. by considering the consistency of its surface, as
well any deviation from the roundness that is to be expected of the
coil that is to be wound, in order to provide an elastic substance,
in particular, a solidifying foam that is projected into the coil
to such a degree that a completely or nearly round coil is created.
This way, the apparatus in accordance with the invention is
particularly suited for winding metallic split strips, in
particular of steel, but also other strip materials, perhaps made
of plastic, for example, thermosetting plastics or thermoplastic
resins. The materials serving as intermediate layer in accordance
with the invention preserve the strip surfaces and improve the
ability of winding. The advantages of evenly wound coils are also
reflected in better transportability and in the facilitation of
further processing. Even changes in the thickness of the strip,
whether in longitudinal or transverse direction can be set at any
time by changing the application of the material.
Advantageous further developments of the invention are
given by the subordinate claims.
According to the invention, the material of the
intermediate layer is doctored onto the uppermost layer of the
wound section of the strip with a scraper or sprayed or squirted
out of series of adjacent nozzles onto the surface of the wound
section. The material, for example a plastic foam can thereby also
be sprayed on across the width that corresponds to the desired
application thickness in various thicknesses, and individually over
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certain zones of the width of the roll. Even in the case of
coating with a scraper, the scraper is either set for the entire
width of the roll at the same distance or it is angled relative to
the axis of rotation of the roll in order to compensate for the
emerging tapered winding of the coil.
Preferably, the device extends over the entire width of
the coil or at least over a large part of the width of the coil.
In the latter case, only the critical zones are covered in which
according to experience irregularities tend to form to a greater
degree.
In a further advantageous embodiment of the invention the
material is applied to the roll in strips. On the one hand, this
approach makes it possible to use as little as possible of the
intermediate material, on the other hand, as the result of a force
exerted radially onto the coil by material during application, the
material can escape into sections between the strips, in order to
thus create an optimally round coil.
In a different embodiment of the invention, the plastic
is advantageously applied to the coil from an extruder.
To increase elasticity the plastic is formed by a
continuous layer or is formed by a number of adjacent strips in the
roll direction of the strip that have air pockets. On foaming, air
or a different gas is inserted into the hardening plastic
corresponding to the desired elasticity, in order to later compress
the intermediate layer either under its own weight or that of the
material to be wound or subject to the influence of a radially
exerted contact force.
In order to improve application of the material layer
even more, a device for measuring the strip thickness of the metal
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strip that is to be wound can be employed that transmits the strip
thickness values measured by it to a controller. It then derives a
control variable from the signals corresponding to the strip
thicknesses, in order to control the material delivery from the
nozzles, the addition of the foaming material, of air and the like
corresponding to the measured strip thickness of the metal strip or
in the case of a scraper, adjust its position at the roll outer
surface.
The invention also relates to a rolling mill for cold or
warm rolling, one-way or reverse rolling of a metal strip of
varying thickness, in particular a flat or profiled strip, a
flexibly or a profile-rolled metal strip, in particular of steel,
with a roll stand provided with a set of rollers and a control
system for adjusting the roll gap, with a device upstream of the
roll stand for unwinding the metal strip and a winding apparatus
downstream of the roll frame as described above. This way, the
metal strip can have all types of profiles in the longitudinal
and/or transverse direction. The thickness of the strip can change
over the length and/or the width.
In accordance with the invention, the rolling mill
distinguishes itself in accordance with the invention in that a
controller for controlling the rotation speed of the drives of the
two winding apparatuses is provided by a controller for
compensating or regulating the mass flow change of the roll strip
and the strip tension speed that is dependent on it, as well as for
the control of the strip tension, in particular at the points in
time at which the strip acceleration changes and when the thickness
of the strip profile changes. Rolling of the strip can also take
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place in an inline casting and rolling system at the end of which
an apparatus for winding a rolled strip is located.
The invention also relates to a method of winding a strip
of varying thickness, in particular a flat or profiled strip, a
flexibly and/or a profile-rolled metal strip, in particular of
steel, into a coil in which during winding deformable material is
applied to the coil.
The method is characterized in that the deformable
material is applied by nozzles or by means of at least one scraper
to the surface of the strip, in particular the metal strip. In
accordance with the invention, strips that have variable strip
thickness in the longitudinal and/or transverse direction can be
wound. In particular, the strips can have special profiles.
Advantageously, the method is further has the step of
applying material to the metal strip at a thickness that is larger
than the deviation of thickness of the metal strip, and that
subsequently, onto the respectively uppermost end of the coil a
force is exerted, in particular by means of a roll, in order to
compress the material in such a way that at least an essentially
cylindrical composite coil is created out of the metal strip and
the material.
In particularly advantageous manner, the method is
performed such that the material is induced to expand or foam as
the result of the addition of an additive shortly before
application or during application.
Various forms of irradiation can be used, in particular
shortly prior to the application or during the application, in
order to promote the expansion or the foaming and/or the hardening.
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In the following, the invention is explained in more
detail in an example of an embodiment. The sole figure shows a
device movable transversely of a coil for spraying foam onto the
uppermost turn of the coil into the gap between the winding strip
and the coil.
A device 1 (Figure) for applying or spraying a plastic
foam onto a coil 2 of a metal strip 3 has a stationary base 4. It
carries two pairs of support blocks 5 for axles 6 on which
respective rollers 7 can rotate. The pairs of spaced rollers 7
serve to guide respective U-shaped guide rails 8 connected to a
support 9 for the device 1. They are so long that they project
past the support 9. The base 4 is projects transversely past the
strip width that is the same as the length of a winding mandrel 10,
so that the device 1 can be move past or underneath the strip
upstream of the winding mandrel 10. At the end of the winding
process, the coil 2 reaches a maximum outside diameter. At the
beginning of the winding process, an extension 11 for spraying or
applying the plastic of device 1 is in an inner position 11' shown
by a dotted line in order to apply the material close to the
surface onto the metal strip 3, while it moves into an outer
position 11" toward the end of the winding process.
The device 1 can pivot on the support 9, since the
support 9 has a pivot axis 12 for two levers 13 that can be jointly
pivoted by a hydraulic actuator 14 that itself is pivoted on a pair
of support lugs 16 on the guide rails 8. The device 1 has a pair
of arms 17 pivoted on a threaded bolt 18 at free ends of the levers
13 and supported by a pair of rollers 19 on guide edges 20 of the
support 9.
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The device 1 has a telescopic actuator 21 that is carried
on the arms 17 in order to position the extension 11 at a suitable
spacing from the surface of the strip 3 or in order to, for example
for cleaning, move it temporarily away from the coil 2. The
extension 11 preferably holds an exchangeable cartridge for
applying the application material that is preferably sprayed on by
one or more nozzles 22 spaced along the axis of winding mandrel 10.
At least one hose 23 can supply various substances
required to make the application medium, in particular also along
with a pressurized gas in order to force the substance that is to
be applied out of the cartridge. In addition, a heater (not shown)
can be provided in the proximity of the nozzles 22 to promote
hardening of the material that has been applied.
In place of a fluid, foam-like or viscous material, in
particular a plastic, a granulate, in particular along with a
plastic or an adhesive or a quilt-like material, for example, with
selectively optimized small cells can also be inserted into the
roll 2 in order to promote even winding. Depending on need, the
cells are intact, filled, at least in certain sections, with
suitable materials or media. These can then, subject to certain
pressure or temperature conditions, in particular after the
conclusion of the winding process, leave the cells.
According to the invention, the use of (here shown only
schematically) a contact pressure roll 24 can also be provided that
evens out the foam or the cushion material or the granulate located
in the coil 2 by pressing radially inward after it has been
applied.
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Reference numbers
1 device
2 coil / roll
3 strip
3' position of strip 3
4 base
support blocks
6 axles
7 rollers
8 guide rails
9 support
winding mandrel
11 extension
11' position of extension 11
11" position of extension 11
12 pivoting axis
13 pivoting lever
14 actuator
bearing
16 support lugs
17 pair of lugs
18 threaded bolt
19 pair of rolls
guide bar
21 operating control
22 nozzle
23 supply hose
24 contact pressure roll
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