Note: Descriptions are shown in the official language in which they were submitted.
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SPREADABLE COILER DRUM
The invention relates to a winder mandrel with radially moveable spreading
segments which are arranged on the periphery, a mandrel body and a pulling
rod, and a method for operating such a winder mandrel.
Winder systems are used for example in order to wind rolled sheet metal or
other materials into a coil on a winder mandrel and/or to unwind a coil. For
winding, the spreading segments are deflected radially outwards in such a
manner that the outer periphery of the spreading segments forms a circle. In
order to unwind a coil, the diameter of the winder mandrel must become smaller
than the inner diameter of the coil in order to accommodate the coil. To this
end,
two diameters can usually be produced in a winder mandrel in a targeted
manner, with only a spread, maximum diameter being configured to be
completely round.
In known embodiments of winder mandrels of this type, winder segments are
deflected radially by means of wedge faces which are moved by means of
pulling or pushing rods.
DE 35 02 452 Al describes a winding and/or unwinding winder for rolled strips,
with a drum which consists of a plurality of segments which can be moved in a
spreading manner and bear with wedge-shaped sliding surfaces against a
winder shaft which is mounted such that it can rotate in a winder housing. A
punch is guided in the winder shaft, which punch is connected by means of a
connecting flange to the drum segments. An actuator effects a relative axial
displacement between the winder shaft and the punch connected to the
segments, by means of which displacement a spreading movement of the
segments is brought about. Furthermore, the winder has a displacing drive
which effects the displacement in and out of the winder drum relative to the
coil
and/or the strip centre regulator, with the winder shaft being mounted in the
stationary winder housing in such a manner that it can be displaced axially,
the
actuator having in order to subject the winder shaft to a despreading load a
piston-cylinder unit which is rotationally fixed but axially displaceable with
respect to the stationary winder housing, a pressure spring constantly holding
the segments in the spread state, and the displacing drive consisting of a
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piston-cylinder unit by means of which the winder shaft can be loaded in such
a
manner that it is displaced axially.
EP 0 504 296 B1 discloses a winder for winding and/or unwinding metal strips
with strip traction forces between 10 kN and 1000 kN, consisting of a
spreadable winding drum which is supported by a hollow shaft mounted in two
places in a stand and can be actuated via a driving rod which runs through the
hollow shaft by an actuating cylinder which is arranged on the hollow shaft.
Coupled to the hollow shaft is a drive motor which is arranged between the two
supports of the hollow shaft and consists of a stator and a rotor. The hollow
shaft forms the rotor shaft and the driving rod forms the winding drum shaft
which is mounted in the hollow shaft.
German Laid-Open Specification 1 777 229 describes a spreadable winder
mandrel for winding strip-shaped rolled material, in particular hot-rolled
strips,
with an inner mandrel body and a plurality of spreading segments placed on the
mandrel body. These spreading segments are supported via tappets on wedge
faces of a wedge rod which is mounted concentrically in the mandrel body and
has a number of wedge faces, with the spreading segments being connected by
lugs to a wedge rod which is mounted concentrically in the mandrel body.
DE 30 28 607 C2 discloses a rolled strip winder which already has a punch
which is pretensioned by spring force, held in the spread position and can be
loaded by means of an actuator which is arranged in a stationary and
rotationally rigid manner in such a manner that the segments can be despread.
Other winder systems are disclosed in GB 948,419 and US 4,433,814.
JP 051 54 552, JP 2001 252 716, JP 03 275 255 and JP 58 068 425 disclose
equipping the spreading segments with magnets. In this case, however,
pressure rollers and/or belt wrappers are additionally required during initial
winding and slipping out in order to catch the strip during initial winding
and
guide the strip end. These devices cause costs in manufacture, installation
and
maintenance. Furthermore, these devices make it more difficult to check the
strip as it exits the rolling train/rolling stand. The disadvantage of the
known
embodiments is that additional lines are let into the shells in order to
generate
the magnetic force. The windings are exposed and corroded over time as a
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result of the shells being abraded and the surfaces being reground. In the
event
of a shell breaking, the magnetic force ceases immediately.
The invention is therefore based on the object of simplifying the known,
expensive designs and avoiding the above-mentioned disadvantages. In
addition, the service life of the spreading segments is to be increased and
the
adjustability of the holding force is to be improved. Furthermore, a device is
to
be created which requires only a small outlay on its construction as a result
of
the use of as few parts as possible.
This object is achieved according to the invention in that in a winder mandrel
with radially movable spreading segments which are arranged on the periphery,
a mandrel body and a pulling rod, the spreading segments and/or the mandrel
body and/or the pulling rod are configured as magnets. This means that belt
wrappers and strip pressure rollers can be dispensed with when winding the
strip.
Further refinements of the winder mandrel can be found in the subclaims
relating to this.
The invention also relates to a method for operating a winder mandrel with
radially movable spreading segments which are arranged on the periphery, a
mandrel body and a pulling rod, with the spreading segments and/or the
mandrel body and/or the pulling rod being configured as electromagnets and
the supply voltage of the electromagnets being switched on during initial
winding of the beginning of the strip, lowered during rolling and raised again
when the strip is slipped out. This saves energy. The supply voltage is
lowered
to a fraction or to zero depending on the properties of the strip.
The use of magnets with regulated magnetic force as spreading segments or
mandrel bodies or pulling rods means the use of pressure rollers and belt
wrappers is avoided. During initial winding, a greater magnetic force is
provided.
The strip is caught and wound on. The magnetic force can be reduced or
switched off during rolling, since the windings of the coil are wound fixedly
and
are not expected to slip. To slip the strip out, the magnetic force is
increased
again. The end of the strip thus lies against the coil and can be rotated into
a
coil lifter.
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In order to prevent the rolled up strip from being magnetised, the magnetic
field
is reverse-polarised after the rolling process and shortly before pulling the
coil
off the winder mandrel.
Current is supplied to the magnetic components spreading segments or
mandrel body or pulling rod by means of a converter. The converter provides an
electric current which can be variably adjusted. This is used to influence the
magnetic force. Three different methods can be used to supply the spreading
segments with electric current:
1. Supply on the drive side by means of slip rings. To this end, a cable is
guided
through the pulling rod with the aid of a milled section. Spreading segments
are
connected with plug-type connectors.
2. Supply on the operation side directly in the vicinity of the respective
spreading segment by means of slip rings. An arrangement of this type must be
protected mechanically against being struck by the strip in the event of the
strip
tearing.
3. The energy is transmitted to the spreading segments by means of induction
loops. A contactless transmission of this type is possible on the operation
side
and must be protected as under point 2.
Winder mandrels in which the spreading segments or the mandrel body or the
pulling rod are configured as magnets can be installed directly or
subsequently
(in exchange) in pay-off reels, tension reels, reversing winders, inspection
winders, double spreading head winders.
A further advantage of the winder mandrel according to the invention consists
in
the straightforward mechanical conversion of existing plant, for example TCM,
SPM, CCM, RCM and CSP, for rolling magnetisable materials, since only the
winder mandrel has to be exchanged. In new plant, investment costs for belt
wrappers, strip pressure rollers and hall foundations are saved.
In one aspect, the present invention provides a method for operating a winder
mandrel comprising a mandrel body with radially movable spreading segments
which are arranged about the periphery of the mandrel body and a pulling rod,
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wherein at least one of the spreading segments, the mandrel body and the
pulling rod are configured as electromagnets, wherein a magnetic force is
regulated in such a way, that a supply voltage of the electromagnets is
switched
on during initial winding of a beginning of a strip, and a greater magnetic
force is
provided during initial winding, and the magnetic force being one of reduced
and switch off during rolling and raised again when the strip is clipped out.
An exemplary embodiment of the invention is described in more detail using a
very schematic drawing. In the figures,
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Fig. 1 shows a winder mandrel with spreading segments, mandrel body and
pulling rod in a longitudinal section; and
Fig. 2 shows the winder mandrel in cross section.
Figure 1 shows a longitudinal section of a winder mandrel 1 which has
spreading segments 2, a mandrel body 3 and a pulling rod 4. The spreading
segments 2 are positioned radially by means of the pulling rod 4. The
spreading
segments 2 form in a radial outer position a circular periphery.
The electrical voltage is transmitted by means of a slip ring 5 which is
connected to the pulling rod 4. If the pulling rod 4 or the mandrel body 3 are
configured as magnets, greater magnetisation forces must be taken into
account since the spreading segments 2 must also be magnetised.
Figure 2 shows the winder mandrel in cross section.
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List of reference symbols
1. Winder mandrel
2. Spreading segment
3. Mandrel body
4. Pulling rod
5. Slip ring
