U.S. patent application number 17/053433 was filed with the patent office on 2021-08-12 for separating flexibly rolled strip material.
The applicant listed for this patent is Muhr und Bender KG. Invention is credited to Andreas Barchet, Christian Bruser, Thomas Dahl, Alexander Eick, Joachim Ivo.
Application Number | 20210245216 17/053433 |
Document ID | / |
Family ID | 1000005565452 |
Filed Date | 2021-08-12 |
United States Patent
Application |
20210245216 |
Kind Code |
A1 |
Ivo; Joachim ; et
al. |
August 12, 2021 |
SEPARATING FLEXIBLY ROLLED STRIP MATERIAL
Abstract
Separating flexibly rolled strip material can include a buffer
device for temporarily storing the flexibly rolled strip material;
a first feed device behind the buffer device; at least one length
measuring device for continuously measuring a length of the strip
material; a thickness measuring device for continuously measuring a
thickness of the strip material along the length; a second feed
device behind the first feed device; a separating device behind the
second feed device; the first and second feed devices being
configured to move the strip material from the buffer device to the
separating device depending on the thickness measurement and the
length measurement; the thickness measuring device being arranged
between the buffer device and the first feed device; and the length
measuring device being arranged behind the first feed device.
Inventors: |
Ivo; Joachim; (Lennestadt,
DE) ; Dahl; Thomas; (Attendorn, DE) ; Barchet;
Andreas; (Lennestadt, DE) ; Bruser; Christian;
(Olpe, DE) ; Eick; Alexander; (Plettenberg,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Muhr und Bender KG |
Attendorn |
|
DE |
|
|
Family ID: |
1000005565452 |
Appl. No.: |
17/053433 |
Filed: |
May 3, 2019 |
PCT Filed: |
May 3, 2019 |
PCT NO: |
PCT/EP2019/061408 |
371 Date: |
November 6, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B21B 2015/0014 20130101;
B21B 2261/12 20130101; B21B 2261/043 20130101; B21B 15/0007
20130101; B21B 38/04 20130101; B21B 41/00 20130101 |
International
Class: |
B21B 38/04 20060101
B21B038/04; B21B 15/00 20060101 B21B015/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 8, 2018 |
EP |
18171364.5 |
Claims
1.-15. (canceled)
16. An apparatus for separating flexibly rolled strip material,
comprising: a buffer device arranged to temporarily buffer the
flexibly rolled strip material; a first feed device which is
arranged in feed direction of the strip material behind the buffer
device; at least one length measuring device configured to
continuously measure a length of the strip material; a thickness
measuring device configured to continuously measure a thickness of
the strip material along the length; a second feed device arranged
behind the first feed device; and a separating device which is
arranged in the feed direction of the strip material behind the
second feed device; wherein the first feed device and the second
feed device are configured to move the strip material depending on
a thickness measurement and a length measurement from the buffer
device to the separating device; wherein the thickness measuring
device is arranged in the feed direction of the strip material
between the buffer device and the first feed device; and wherein
the at least one length measuring device is arranged in the feed
direction of the strip material behind the first feed device.
17. The apparatus of claim 16, wherein a coiler for uncoiling the
flexibly rolled strip material and a straightening unit for
straightening the flexibly rolled strip material are provided,
which are arranged upstream of the buffer device, wherein the first
feed device and the second feed device for the separating device
are controlled independent of a feed of the coiler and the
straightening unit.
18. The apparatus of claim 16, wherein the at least one length
measuring device comprises a measuring wheel which is in contact
with a first side of the strip material, and a support wheel which
is in contact as a counter-bearing for the measuring wheel with an
opposite side of the strip material, wherein a running surface of
the measuring wheel is made from a steel material.
19. The apparatus of claim 16, wherein the at least one length
measuring device comprises a first length measuring device for
measuring the length of the strip material, and a second length
measuring device for measuring the length of the strip material,
wherein the second length measuring device is arranged in the feed
direction of the strip material between the second feed device and
the separating device.
20. The apparatus of claim 19, wherein the first length measuring
device has a first distance to the first feed device which is
smaller than 0.5 times a distance between the first feed device and
the second feed device, and wherein the second length measuring
device has a second distance to the second feed device which is
smaller than 0.5 times a distance between the second feed device
and the separating device.
21. The apparatus of claim 16, wherein the second feed device is
drivable faster than the first feed device, so that the strip
material is tension loaded between the first feed device and the
second feed device.
22. The apparatus of claim 16, wherein a distance between the
thickness measuring device and the separating device is at least
twice a blank length of a blank to be cut out of the strip
material.
23. The apparatus of claim 16, wherein the at least one length
measuring device and the thickness measuring device are measuring
technically coupled to one another, wherein the length measuring
device generates trigger signals and transmits them to the
thickness measuring device, with the trigger signals serving as
triggers for carrying out thickness measurements.
24. The apparatus of claim 16, wherein the separating device
comprises a cross-cutting shear or a laser cutting unit.
25. A method for separating flexibly rolled strip material, by an
apparatus comprising a buffer device arranged to temporarily buffer
the flexibly rolled strip material; a first feed device which is
arranged behind the buffer device in feed direction of the strip
material; at least one length measuring device configured to
continuously measure a length of the strip material; a thickness
measuring device configured to continuously measure a thickness of
the strip material along the length; a second feed device arranged
behind the first feed device; and a separating device which is
arranged behind the second feed device in the feed direction of the
strip material; wherein the first feed device and the second feed
device are configured to move the strip material depending on a
thickness measurement and a length measurement from the buffer
device to the separating device; wherein the thickness measuring
device is arranged, in the feed direction of the strip material,
between the buffer device and the first feed device; and wherein
the at least one length measuring device is arranged, in the feed
direction of the strip material, behind the first feed device; the
method comprising: performing intermediate buffering of the
flexibly rolled strip material by the buffer device; advancing the
strip material from the buffer device by the first feed device and
the second feed device; continuously measuring a thickness of the
strip material by the thickness measuring device while the strip
material is being fed forward, wherein the measuring of the
thickness takes place in the feed direction of the strip material
upstream of the first feed device; continuously measuring a length
of the strip material by the length measuring device while the
strip material is being fed forward, the length being measured in
the feed direction of the strip material behind the first feed
device; calculating an actual thickness profile for a blank to be
separated from the strip material from measured thickness values
and associated measured length values; comparing the calculated
actual thickness profile with a predetermined nominal thickness
profile and calculating a feed length for the blank to be separated
from the strip material; and feeding the strip material to the
separating device by the first feed device and the second feed
device on the basis of the calculated feed length.
26. The method of claim 25, further comprising: continuously
measuring the length of the strip material by the second length
measuring device during the feeding of the strip material to the
separating device, wherein the continuous measuring takes place by
the second length measuring device in the feed direction of the
strip material behind the second feed device; comparing the first
length measured values determined by the first length measuring
device with the associated second length measured values determined
by the second length measuring device; and switching off the
apparatus if a difference between the first length measured values
and the second length measured values exceeds a specified
difference value.
27. The method of claim 25, wherein the first length measuring
device is referenced at a starting point with the thickness
measuring device with respect to the length, wherein the length
measuring device generates trigger signals and transmits them to
the thickness measuring device, with the trigger signals serving as
triggers for carrying out thickness measurements by the thickness
measuring device.
28. The method of claim 25, wherein the first feed device and the
second feed device are operated synchronously.
29. The method of claim 25, wherein the first feed device and the
second feed device are controlled such that the second feed device
runs faster relative to the first feed device, so that the strip
material is subjected to a tensile load.
30. The method of claim 25, wherein a fixed first distance is set
between the thickness measuring device and the first feed device,
wherein a fixed second distance is set between the thickness
measuring device and the separating device, and wherein at least
one of the first distance and the second distance are measured with
an accuracy of up to +/-0.2 mm.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a national stage of, and claims priority
to, Patent Cooperation Treaty Application No. PCT/EP2019/061408,
filed on May 3, 2019, which application claims priority to European
Application No. EP18171364.5, filed on May 8, 2018, which
applications are hereby incorporated herein by reference in their
entireties.
BACKGROUND
[0002] From CN 104551538 B a device and a method for separating
flexibly rolled strip material are known. The strip material is fed
from a coiler to a strip accumulator via a first clamping roller
and a strip straightening arrangement. Behind the strip accumulator
there are two further clamping rollers with integrated length
measurement, between them a strip thickness measurement, and behind
them a hydraulic shear for separating the strip material. The first
clamping roller determines the strip length fed to the strip
accumulator and the clamping roller arranged behind the strip
accumulator determines the strip length fed out of the strip
accumulator. By integrating the difference between the fed-in strip
length and the fed-out strip length over time, the strip length
stored in the strip accumulator can be determined. If the stored
strip length in the strip accumulator exceeds a nominal value,
strip material is fed via the clamping roller arranged behind the
strip accumulator and the subsequent thickness measuring unit, and
an actual thickness profile of the strip material is determined.
Based on the actual thickness profile, a cutting plan is determined
according to which the fed length of the strip material is
controlled and the cutting process is carried out. The strip length
fed to the hydraulic shear is determined by averaging the values
determined by the clamping rollers arranged immediately before and
behind the thickness measurement.
[0003] From EP 3 181 248 A1 a process and an apparatus for
producing a sheet metal blank are known. The method includes the
steps: flexible rolling of a strip material, wherein a thickness
profile with different sheet thicknesses is produced over the
length of the strip material; determining a measuring thickness
profile of several regions of the strip material lying one behind
the other; calculating a desired position in the strip material for
a sheet blank to be cut from the strip material as a function of
the generated measuring thickness profile of at least two regions
of the strip material lying one behind the other; cutting the
flexibly rolled strip material by at least one cutting device along
the desired position for producing the sheet blank.
[0004] The production of shaped cuts and rectangular blanks, also
known as Tailor Rolled Shapes or Tailor Rolled Blanks, can be
carried out using a suitable separating device. For this purpose,
the strip feeding device arranged in front of the cutting device is
equipped with a decoiler, a straightening machine, a strip
buffering unit and a feeding device. The threading of a metal strip
into such an apparatus is done manually by the operator. The
operator threads the beginning of the strip up to a marked position
in the cutting tool or on the cross-cutting shear. The automatic
mode is then started and the feed system feeds the strip forward by
a predetermined length per working stroke, which is always the
same. With this procedure, the cyclic thickness profile of the
flexibly rolled strips can only be positioned inaccurately or not
at all to the separating edge of the cutting device. This means
that position tolerances for the thickness profile relative to the
position within the contour cut or the rectangular blank cannot be
fulfilled. In addition, areas of the metal strip that do not comply
with the thickness tolerances cannot be detected and sorted out.
Furthermore, it is not possible to position cyclically recurring
thickness profiles in the flexibly rolled strips automatically and
precisely on the cutting edges of the cutting devices.
SUMMARY
[0005] Disclosed herein is an apparatus and a method for separating
flexibly rolled strip material. Flexibly rolled strip material has
a variable thickness profile in the longitudinal direction of the
strip. The separation of flexibly rolled strip material therefore
requires exact positioning of the separation region in order to
obtain blanks with a defined nominal thickness profile. Disclosed
herein is a apparatus for separating flexibly rolled strip
material, which enables precise measurement and evaluation of sheet
thickness profiles and ensures precise positioning of the strip
material for separation. Further disclosed is an appropriate
process for separating flexibly rolled strip material that will
allow accurate measurement, evaluation and positioning.
[0006] An apparatus for separating flexibly rolled strip material
is disclosed, comprising: a buffer device for temporarily buffering
the flexibly rolled strip material; a first feed device arranged
behind the buffer device in the feed direction of the strip
material; at least one length measuring device for continuously
measuring a length of the strip material; a thickness measuring
device for continuously measuring a thickness of the strip material
along the length; a second feed device arranged behind the first
feed device; a separating device arranged behind the second feed
device in the feed direction of the strip material; wherein the
first feed device and the second feed device are arranged to move
the strip material from the buffer device to the separating device
depending on the thickness measurement and the length measurement;
wherein the thickness measurement device is arranged in the feed
direction of the strip material behind the buffer device and in
front of the first strip feed device; and the at least one length
measurement device is arranged in the feed direction of the strip
material behind the first strip feed device.
[0007] The apparatus has the advantage that the feed applied by the
first feed device can be controlled on the basis of the values
previously determined by the thickness measuring device. A
recurring thickness profile of the flexibly rolled strip can be
precisely detected, compared with the desired target profile and
positioned exactly in the separation position of the separating
device. In addition, areas of the metal strip that do not comply
with the thickness tolerances can be identified and sorted out.
[0008] According to an embodiment, the apparatus can have a coiler
for uncoiling the flexibly rolled strip material and at least one
straightening unit for straightening the flexibly rolled strip
material. Several straightening units can be used in particular for
processing particularly thick strips and/or for strips with large
absolute thickness increments of, for example, more than 1 mm. The
coiler and the at least one straightening unit, which together can
also be referred to as the uncoiling and straightening group, are
connected upstream of the strip buffer device. Preferably, the
first and second feed devices for the separating device are
independently controlled from of the feed of the uncoiling and
straightening group. The uncoiling and straightening group conveys
the strip into the strip accumulator and makes the flexibly rolled
strips available for processing by the further apparatus. The
conveying respectively uncoiling speed of the uncoiling and
straightening group can be controlled by a filling level sensor of
the strip accumulator. For example, the filling level sensor can be
an ultrasonic unit that senses the depth of the strip loop hanging
in the strip accumulator and transmits a corresponding signal to
the controller for the uncoiling and straightening group. It is to
be understood that other sensors can also be used, such as an
optical sensor, a capacitive sensor and/or an inductive sensor. The
straightening unit can be supported by an infeed driver and a
take-off roller. The operation or running of the coiler, inlet
driver, straightening unit and take-off roller can be synchronized
with each other via controllers and can be operated in speed
control or torque control to each other. Each of the units can be
operated individually, i.e. independently of the others, as a
generator or motor. The embodiment with decoiler and straightening
group is suitable when the strip material is rewound into a coil
after flexible rolling and further processed elsewhere. In
principle, however, it is also possible that the strip accumulator,
feed and separation unit directly follow a flexible rolling in the
continuous process.
[0009] The strip accumulator serves to decouple the uncoiling and
straightening group of the apparatus from the position-controlled
part of the apparatus which operates on the basis of feed lengths,
with the components thickness measurement, feeds, length
measurement and separating device. In particular, it is provided
that the length-based feed control of the separating unit is based
only on the length measurement values of the length measuring
device located behind the strip accumulator. Any measured length
values measured before the buffer device can be ignored by the feed
control in this case.
[0010] The thickness measuring unit is arranged in feed direction
behind the strip buffer and in front of the first feed device. The
corresponding first length measuring unit is located directly
behind the first feed device. The first length measuring unit is
designed to continuously measure the length of the strip material.
Thickness measurement is also carried out continuously during the
strip feed. Preferably the length measuring device and the
thickness measuring device are coupled with each other in a
measurement technical manner. It is provided in particular that the
length measuring unit generates trigger signals and transmits them
to the thickness measuring unit in order to trigger thickness
measurements, which are then recorded.
[0011] According to an embodiment, the length measuring unit may
include a measuring wheel which is in contact with the first side
of the strip material, and a support wheel which is in contact with
an opposite side of the strip material as a counter bearing for the
measuring wheel. The running surface of the measuring wheel can,
for example, be made of a steel material. The running surface of
the support wheel can, for example, be made of an elastic material.
It is to be understood that the design of the length measuring unit
described above can also be used for any other length measuring
unit in the apparatus.
[0012] According to a preferred embodiment, two length measuring
devices are provided, a first length measuring device which is
assigned to the first feed device, and a second length measuring
device which is assigned to the second feed device. The second
length measuring device is arranged in the feed direction of the
strip material after the second feed device and before the
separating device. For a high measuring accuracy it is advantageous
if the measuring devices are arranged as close as possible to the
respective feeds. Preferably the first length measuring device has
a first distance to the first feed device which is smaller than 0.5
times, in particular smaller than 0.25 times, the distance between
the first feed device and the second feed device. The second length
measuring device may have a second distance from the second feed
device which is smaller than 0.5 times, in particular smaller than
0.25 times, the distance between the second feed device and the
separating device.
[0013] The two feed devices work synchronously to feed the strip
material from the strip accumulator to the separating unit. Both
feeds exert a tensile force to the strip material to move it. To
ensure that the strip material is kept flat between the two feed
devices, the second feed device, which is located downstream in the
feed direction, may be driven in particular faster than the
upstream first feed device. In this way, the strip material between
the two feed devices is held slightly in tension and is thus flat,
which has a positive effect on the measured value accuracy.
[0014] According to a preferred embodiment, the distance between
the thickness measuring device and the separating device is at
least twice the blank length of a blank to be cut from the strip
material. In particular, the distance is at least twice the length
of a blank plus the feed path covered by the strip material during
the computing time for a blank to be cut.
[0015] The separating device can be selected according to the
requirements of the flat product to be separated and can comprise,
for example, a cross-cutting shear or a beam cutting unit, in
particular a laser cutting unit. For simply cutting to length of
blanks, a cross-cutting shear, a cross-cutting laser or a
comparable beam system for cross-cutting can be used in conjunction
with the strip feed system. For producing shaped cuts, a press line
with suitable cutting tools or a beam cutting unit, in particular a
laser beam unit, can be used which in each case are connected to
the strip feed apparatus.
[0016] A solution to the above object further is a process for
separating flexibly rolled strip material, in particular by an
apparatus according to any one of the above embodiments, comprising
the steps: buffer storing the flexibly rolled strip material by a
buffer device; feeding the strip material from the buffer storage
by a first feed device and a second feed device; continuously
measuring a thickness of the strip material by a thickness
measuring device while the strip material is being advanced, with
the thickness being measured in the feed direction of the strip
material upstream of the first feed device; continuously measuring
a length of the strip material by a length measuring device while
the strip material is being advanced, with the length being
measured in the feed direction of the strip material downstream of
the first feed device; calculating an actual thickness profile for
a blank to be separated from the strip material from measured
thickness values and associated measured length values; comparing
the calculated actual thickness profile with a predetermined
nominal thickness profile and calculating a feed length for the
blank to be separated from the strip material; feeding the strip
material to a separating device by the first feed device and the
second feed device on the basis of the calculated feed length.
[0017] The length measurement behind the respective feed unit
decouples the feed movement from the length measurement, which
leads to particularly accurate measurement results. The thickness
measurement before the first feed unit also has a positive effect
on the measuring accuracy, since the feed applied by the first feed
unit can be controlled by means of the values previously determined
by the thickness measuring unit. The use of the second
position-controlled feed device with associated length measuring
unit contributes to a flat, warp-free and loop-free strip run
between the thickness measuring unit and the cutting point, which
in turn ensures precise positioning of the reference edges of the
feed lengths in relation to the cutting point. The advantages for
the process as a whole are the same as for the apparatus. A
recurring thickness profile of the flexibly rolled strip can be
precisely detected, compared with the desired target profile and
positioned exactly relative to the separation point of the
separating device. In addition, areas of the metal strip that do
not comply with the thickness tolerances can be identified and
sorted out. It is understood that all procedural features can be
applied analogously to the apparatus and vice versa, all
apparatus-related features can be applied to the process.
[0018] According to a method embodiment, the strip material is
pulled out of the strip buffer storage by the position-controlled
first and/or second strip feed. The flexible rolled strip is
continuously measured with respect to thickness by the thickness
measuring unit. On the basis of the measured thickness and taking
into account the corresponding measured length values, the
thickness measuring unit evaluates whether the flexible rolled
strip corresponds to the required thickness tolerances or not. The
comparison of the determined actual thickness profile with the
predefined target thickness profile is carried out in particular
taking into account the associated tolerances of the target
thickness profile, which can be represented by an envelope curve.
Thereby, it is examined whether the determined actual profile lies
within the envelope of the target profile. From the result of the
comparison, the feed length for the strip respectively the blank to
be cut therefrom, and the cutting position of the blank in the
strip can be calculated. The strip is divided into areas that are
OK (so-called OK parts) and areas that are not OK (so-called not OK
parts). The position and length of these individual regions in the
strip is transferred from the thickness measuring device to the
first feed device. The first feed device, and also the second feed
device coupled to it, can then carry out the feeds instructed by
the thickness measuring unit and position the reference edges of
the individual feed lengths precisely at the cutting point of the
cutting device. The feed unit can pass on the information to the
other system components as to whether the feed length is a length
with OK thickness profile or not OK thickness profile.
[0019] The length measuring device is designed to continuously
measure a length value representing the feed path of the strip.
Preferably, high-precision length measuring devices are used which
have a measuring tolerance of up to 0.5 mm per metre strip length,
in particular of up to 0.1 mm per metre strip length. The length
can be measured, for example, by means of a measuring wheel which
is in contact with the passing strip material. The length measuring
device can measure the strip material from beginning to end without
interruption. The starting point of the measurement can be the
beginning of the strip, which defines the zero position of the
length accordingly. From the starting point of the length
measurement, the length is continuously measured.
[0020] According to a preferred method embodiment, the first length
measuring device of the first feed is referenced at the starting
point with the thickness measurement with regard to the length.
This can be done by continuously transmitting the measured length
value from the first length measuring device to the thickness
measuring device. The length measured values can be indicated
either absolutely or incrementally. The thickness measurement
scales the thickness measurement values based on the indicated
length measurement values along the strip length. In this way, both
measuring instruments can work from exactly the same strip length
zero point. The measured actual thickness profile can be reliably
compared with the specified nominal thickness profile and a
corresponding evaluation can be made with regard to the parts that
are OK and those that are not. The referencing of the length
measuring device with the thickness measuring device is also
important for the position-accurate positioning of the feed lengths
by the feed device in relation to a reference cutting position for
separating. Alternatively or in addition, the second length
measuring device of the second feed can be referenced at the
starting point with the thickness measurement with regard to the
length.
[0021] According to an embodiment, a further length measurement of
the strip material can be carried out by a second length measuring
device during the feeding of the strip material to the separating
device, wherein the length measuring by the second measuring device
is carried out in the feed direction of the strip material behind
the second feed device. It may also be provided as a further
process step: comparing the first measured length values determined
by the first length measuring device with the associated second
measured length values determined by the second length measuring
device; and switching off the apparatus if a difference between the
first measured length values and the second measured length values
exceeds a predetermined difference value. This embodiment provides
a measurement redundancy so that the risk of outage parts is
reduced.
[0022] According to a method embodiment, a fixed distance can be
set between the thickness measuring device and the first feed
device. This distance is measured precisely, preferably with an
accuracy of up to +/-0.2 mm (millimeters), and maintained during
operation of the apparatus. In this way, the length reference
between the thickness measurement on the one hand and the feed
respectively length measurement on the other hand can be reliably
guaranteed over the entire length of the strip material.
[0023] For the precise positioning of a reference edge of a feed
length to a reference separating position of the separating device,
a fixed distance can be set between the thickness measuring device
and the separating device according to a possible embodiment. This
distance is measured precisely, preferably with an accuracy of up
to +/-0.2 mm, and is maintained during operation of the
apparatus.
[0024] According to a further method embodiment, the measuring
distance between the thickness measurement and the separating
device can be set to at least twice the blank length of a blank to
be cut out of the strip material. In particular, the distance
between the thickness measurement and the separating device can be
set to at least twice the length of a blank plus the feed path
covered by the strip during the computing time for a blank to be
cut.
[0025] As far as reference is made in this disclosure to a distance
between two devices, this may refer to a given reference point of
the respective device, e.g. a measuring plane at the measuring
devices, or a separation point at the separating device.
[0026] According to a preferred method embodiment, the second feed
device is operated synchronously with the first feed device, in
particular with the same length scale as the first feed device and
the thickness measuring unit. By controlling in a manner that the
second feed unit advances slightly relative to the first feed unit,
the second feed unit generates a light strip tension in the strip
section located within the measuring path, which ensures a flat
strip run.
BRIEF SUMMARY OF THE DRAWINGS
[0027] Embodiments are explained below using the drawing figures.
Herein:
[0028] FIG. 1 shows an exemplary apparatus for separating flexibly
rolled strip material schematically in three-dimensional
representation in a first embodiment;
[0029] FIG. 2 shows a process for separating flexibly rolled strip
material;
[0030] FIG. 3 shows the thickness profile of an exemplary blank
that can be produced with the apparatus and process shown in FIGS.
1 and 2;
[0031] FIG. 4 shows the thickness profile of another exemplary
blank that can be produced with the apparatus and process described
in FIGS. 1 and 2;
[0032] FIG. 5 shows the thickness profile of another exemplary
blank that can be produced using the apparatus and process shown in
FIGS. 1 and 2;
[0033] FIG. 6 shows an exemplary sequence of several blanks
according to FIG. 3 or FIG. 4;
[0034] FIG. 7 shows an exemplary apparatus for separating flexibly
rolled strip material schematically in three-dimensional
representation in a second embodiment;
[0035] FIG. 8 shows an exemplary contour cut in top-view, which can
be produced with the apparatus according to FIG. 7 and the process
according to FIG. 2, respectively;
[0036] FIG. 9 shows an exemplary sequence of several contour cuts
as shown in FIG. 8.
DESCRIPTION
[0037] FIGS. 1 through 9 are described jointly below. FIG. 1 shows
an exemplary apparatus 2 for separating flexibly rolled strip
material 3. Flexible rolled strip material means that a strip
material with a substantially constant sheet thickness is rolled
along its length by rollers in such a way that it obtains a
variable sheet thickness along the rolling direction. After
flexible rolling, the strip material has 3 different thicknesses
over its length in the rolling direction. After flexible rolling,
the strip material 3 is coiled-up to a coil 4 so that it can be fed
to the next process step, or it can be further processed directly
if applicable.
[0038] A coil 4 of flexible rolled strip material is shown as
starting material. The apparatus 2 comprises a coiler 5 for
uncoiling the flexibly rolled strip material 3 and a straightening
unit 6 for straightening the flexibly rolled strip material. The
straightening unit 6 comprises a plurality of rolls, in particular
between 7 and 23 rolls, which the strip material passes through.
Between the coiler 5 and the straightening unit 6 an infeed driver
7 can be provided, which pulls the strip material 3 from the coiler
and feeds it to the straightening unit. A take-off roller 8 can be
arranged behind the straightening unit 6 in the feed direction of
the strip, which transmits a feed force to the strip material 3.
The operation of the apparatus components coiler, infeed driver,
straightening unit and take-off roller can be synchronized with
each other via controllers and operated in speed control or torque
control to each other. Each of the units can be operated
individually, i.e. independently of the others, as a generator or
motor. FIG. 1 shows the moments M5, M6, M7, M8 that can be
transmitted from the respective components 5, 6, 7, 8 to the strip
material.
[0039] In the strip feed direction behind the uncoiling and
straightening group 10, a buffer device 9 is provided, which is
designed to temporarily store a respective section of the strip 3.
A feed movement of the uncoiling and straightening group 10 is
decoupled from a feed movement of the separating group 12. The
uncoiling and straightening group 10 conveys the strip 3 into the
strip buffer storage 9, which makes the flexibly rolled strip 3
available for further processing in the separating group 12. The
conveying respectively uncoiling speed of the uncoiling and
straightening group 10 can be controlled by a level sensor 13 of
the strip buffer storage 9. The level sensor 13 can, for example,
include an ultrasonic sensor or an optical sensor which senses the
depth of the strip loop hanging in the strip accumulator and
transmits a corresponding signal to the controller for the
uncoiling and straightening group 10.
[0040] The apparatus 2 comprises as further components behind the
buffer device 9 a thickness measuring device 14 for continuous
measurement of the thickness of the strip material, a first feed
device 15, a first length measuring device 16 associated with the
first feed device for continuous measurement of the length of the
strip material 3, a second feed device 17 which is arranged at a
distance behind the first feed device 15, a second length measuring
device 18 associated with the second feed device 17 and a
separating unit 19 for separating the strip material 3.
[0041] The two feed devices 15, 17 are operated synchronously and
are designed to move the strip material 3 from the buffer device 9
to the separating device 19 depending on the thickness measurement
and the length measurement. The two feeds 15, 17 each exert a feed
force on the strip material in order to move it. In order to keep
the strip material flat between the two feed devices 15, 17, the
second feed device 17 can be driven with a slight advance compared
to the first feed device 15. A special feature of the present
arrangement is that the thickness measuring device 14 is arranged
in the feed direction R of the strip material 3 behind the buffer
device 9 and before the first feed device 15, and that the first
length measuring device 16 is separate from the first feed device
15 and is arranged downstream thereof. For the length-based feed
control of the separating group 12, only the length measuring
values of the length measuring devices 16, 18 located behind the
strip buffer 9 are used as a basis.
[0042] The first length measuring device 16 and the thickness
measuring device 14 are coupled with each other with respect to
measurement technique. A fixed distance A1 is set between the
thickness measuring device 14 and the first feed device 15 in order
to reliably maintain the length reference over the strip length
between the thickness measurement device 14 on the one hand and the
first feed device 15, respectively the first length measurement
device 16, on the other hand. This distance A1 is measured
precisely, preferably with an accuracy of up to +/-0.2 mm, and
maintained during operation of the apparatus. In this way, the
length reference between the thickness measurement on the one hand
and the feed respectively length measurement on the other hand can
be reliably guaranteed over the entire length of the strip
material. During operation of apparatus 2, the length measuring
unit 16 can generate trigger signals B1 and transmit them to the
thickness measuring unit 14. Each trigger signal B1 serves as a
trigger for a thickness measurement, so that with each trigger
signal of the length measuring unit 16 a thickness measurement
value is generated and assigned to a corresponding length
measurement value. In this way, data records are generated from
pairs of length and thickness values, from which the actual
thickness profile of the blank to be cut from strip material 3 can
be determined.
[0043] The first and second length measuring units 16, 18 each
comprise a measuring wheel 20, 20', which is in contact with a
first side of the strip material 3, as well as a support wheel 21,
21', which serves as a counter bearing for the measuring wheel 20,
20'. The running surface of the measuring wheels can, for example,
be made of a steel material. The running surface of the support
wheels, for example, can be made of an elastic material. It is to
be understood, however, that other forms of length measurement,
such as non-contact sensors, can also be used. For a high measuring
accuracy of the measured length values, it is advantageous if the
measuring devices 16, 18 are arranged as close as possible to the
respective feeds 15, 17. In particular, the distance between the
first length measuring device 16 and the first feed device 15 may
be less than 0.1 times the distance between the two feed devices
15, 17. The distance between the second length measuring device 18
and the second feed device 17 may be less than 0.1 times the
distance between the second feed device 17 and the separating
device 19.
[0044] FIG. 1 further shows the distance A2 between the thickness
measurement device 14 and the separating device 19. This is
preferably at least twice the blank length L22 of a blank 22 to be
cut out of the strip material 3 plus the feed path which the strip
material covers during the calculation time for a blank to be cut
out.
[0045] The separating device 19 can be selected according to the
requirements of the flat product 22 to be separated and can, for
example, comprise a mechanical separating device, such as a
cross-cutting shear (as shown here), or a beam cutting unit, in
particular a laser cutting unit. In general, the separating device
can also be described as a cutting or parting device. The present
cutting device 19 is designed to produce cuts perpendicular to the
strip edge. It is to be understood, however, that the separating
device can also be adapted to the final contour of the blank to be
produced with regard to the separating cut to be performed. For
example, the cutting device can also be designed to produce cuts
that run diagonally to the strip edge, or curved cuts. In this way,
as the case may be, the amount of scrap may be reduced.
[0046] Hereinafter, a method for separating flexible rolled strip
material 3 into blanks 22 is described with reference to FIG. 2.
The method can be considered in two parts with regard to the
controlling of the components. This is because the process steps
S10 of uncoiling and S20 of straightening, that are carried out by
the uncoiling and straightening group 10, can be decoupled with
regard to control technique from the process steps (S40-S130) that
are carried out behind the strip buffer store S30 by the feed and
separating group 12, at least with regard to the feed of the strip
material.
[0047] Step S30 provides for temporarily buffering the flexible
rolled strip material 3 by the buffer device 9. In particular, it
is provided that the strip material 3 is continuously fed from the
uncoiling and straightening group 10 into the strip buffer device
9. In step S40, the strip material 3 is fed out of the temporary
buffer store 3 by the first and second feed devices 16, 17. This is
done in particular at intervals according to a calculated feed
length for the blank 22 to be cut out of the strip material 3 in
each case. To determine the feed length, a continuous measurement
of a thickness signal and a length signal of the strip material 3
is carried out in steps S50, S60. This is carried out continuously
by the thickness measuring device 14 and the first length measuring
device 16, i.e. while the strip material 3 is moved by a feed
length by the feed devices 15, 17. The thickness measurement (S50)
is carried out in the feed direction R of the strip material 3
before the first feed device 15 and/or before the first length
measuring device 16.
[0048] The thickness and length values measured by the measuring
devices 14, 16 are transmitted to a calculation or control unit,
respectively, where they are further processed to calculate the
actual thickness profile of a blank 22 to be cut and to calculate
the feed length for this blank. To determine the thickness profile
of the strip, respectively the blanks to be cut therefrom, a
thickness value D is assigned to each length position L of strip
material 3. Since the thickness measuring device 14 is arranged
before the first feed device 15, the thickness values measured by
same and the actual thickness profiles determined therefrom
together with the corresponding length values can be taken into
account directly in the current feed movement. The length
measurement can be carried out in the feed direction R of the strip
immediately behind the first feed device 15.
[0049] The continuous measurement of the length, respectively path
signal of the strip material 3 by the first length measuring device
16 takes place simultaneously with the thickness measurement while
the strip material is being advanced. In particular, it is provided
that the first length measuring device 16 be referenced at the
starting point with the thickness measuring device 14 with regard
to length. This is done for the first time, as described above, by
setting the defined distance dimension A1, as well as during the
process by continuously communicating the measured length value
from the first length measuring device 16 to the thickness
measuring device 14. The communicating of the measured length
values can be absolute or incremental, for example by trigger
signals B1, B2. The thickness measurement scales the thickness
measurement values using the communicated length measurement values
over the strip length. In this way, both measuring devices 14, 16
work from exactly the same strip length zero point. In step S70,
the actual thickness profile for the blank 22 to be separated from
the strip material 3 is calculated from the measured thickness and
length values of the measuring devices 14, 16. The measured actual
thickness profile can be reliably compared with the specified
nominal thickness profile and the associated tolerances, in
particular represented by an envelope curve, in step S80 and a
corresponding evaluation can be made with regard to the parts that
are OK and those that are not. In step S90, the feed length for the
blank 22 to be separated from the strip material 3 can be
calculated at the same time or time-shifted.
[0050] In the subsequent step S100 the strip material 3 is fed to
the separating device 19 by the two feed devices 15, 17 on the
basis of the calculated feed length VL. While the strip material is
fed forward by the calculated feed length VL for a first blank, the
thickness and length measurement for the next blank 22' to be cut
out is carried out simultaneously by the thickness and length
measuring devices 14, 16 in the region of the first feed unit 15.
This is shown by the dashed line in FIG. 2. It is provided that the
measuring distance between the thickness measurement 14 and the
separating device 19 is set to at least twice the blank length L22
of a blank 22 to be cut out of the strip material 3 plus the feed
path which the strip covers during the computing time for the blank
to be cut out. The blank 22 is cut out in process step S110.
[0051] According to a further step S120 a further length
measurement can be carried out by a second length measuring device
18 during the feed of the strip material 3 from the second feed
device 17 to the separating unit 19. The second length measuring
unit is arranged in the feed direction of the strip material 3
preferably directly behind the second feed device 17. It may also
be provided as a further method step S130: comparing the first
length measured values determined by the first length measuring
device 16 with the associated second length measured values
determined by the second length measuring device 18, and switching
off the apparatus if a difference between the first and second
length measured values exceeds a predetermined difference value.
This measurement redundancy minimizes the risk of producing
rejects.
[0052] FIGS. 3, 4 and 5 show various shapes of blanks to be
produced from the strip material 3, and FIG. 6 shows an example of
a separation sequence for a blank according to FIG. 3, respectively
a blank according to FIG. 4.
[0053] FIG. 3 shows a rectangular blank 22 with an asymmetrical
thickness D22 over the length L22 of the blank. Starting from the
first end 23, the blank 22 has different sections 24a, 24b, 24c,
24d with different thicknesses D24a, D24b, D24c, D24d, wherein the
first section 24a and the last section 24d at the second end 25
have the same thickness (D24a=D24d). Between each two sections 24a,
24b, 24c, 24d of constant thickness, which can also be referred to
as plateaus, a transition section 26a, 26b, 26c of variable
thickness is formed, which can also be referred to as ramps. The
rectangular blank 22 shown in FIG. 3 is produced by simply
separating the strip material 3 brought to the correct position by
the feeders 15, 17 by a simple cut, for example using a
cross-cutting shear. An exemplary separation sequence for the
rectangular blank 22 from FIG. 3 is shown in the upper path of FIG.
6. Successive blanks have the same reference sign with indices.
There is an OK ("i.O.") blank 22, followed by a not OK ("n.i.O.")
blank 28, followed by an OK ("i.O.") blank 22, a short not OK
("n.i.O.") intermediate piece 28 to be separated out, followed by
another OK ("i.O.") blank 22. The OK ("i.O.") blanks 22, 22', 22''
are stacked by a stacking system (not shown). The not OK ("n.i.O.")
sections 28, 28' are automatically scrapped. The lower half of FIG.
6 shows another exemplary separation sequence for another exemplary
rectangular blank. For the rectangular blanks 22, 22', 22'' of the
lower separation sequence, the thicknesses of the first section 24a
and the last section 24a are also the same. The last section 24a of
the blank 22 has the same thickness as the first section 24a' of
the following blank 22'. In the specific example shown, a not OK
("n.i.O.") blank 28 is followed by an OK ("i.O") blank 22, a short
not OK ("n.i.O.") intermediate piece 28 to be separated out,
followed by another OK ("i.O.") blank 22, a not OK ("n.i.O.") blank
28'' and an OK ("i.O.") blank 22''. The OK ("i.O") blanks 22, 22',
22'' are stacked by a stacking system (not shown). The not OK
("n.i.O.") portions 28, 28' are automatically scrapped.
[0054] FIG. 4 shows another embodiment of a rectangular blank 22,
which, in contrast to FIG. 3, has a symmetrical thickness D22 over
the length L22. It can be seen that the thickness profile D22 of
blank 22 is mirror-symmetrical with respect to a middle plane E.
The thickness profile D22 of blank 22 is mirror-symmetrical. The
rectangular blank 22 shown here is also produced by simply cutting
to length the strip material 3 brought to the correct position from
the feeds 15, 17 by a simple cut, for example using a cross-cutting
shear.
[0055] FIG. 5 shows an embodiment of blanks whose end sections each
have a different thickness. For this reason, two successive blanks
22A, 22B are arranged mirrored to each other. A first blank 22A and
a second blank 22B alternate along the length of the strip. The
profile of the first blanks 22A corresponds to the profile of the
second blanks 22B. The blanks 22A, 22B shown here also have an
asymmetrical thickness profile D22A, D22B over the respective
lengths L22A, L22B. It can be seen that the thickness profile D22A
of the blank 22A is mirror symmetrical to the thickness profile
D22B of the following blank 22B in relation to a center plane EAB.
The blank 22A has, starting from the first end 23A, a first section
24Aa with a first thickness, a second section 24Ab with a second
thickness, a third section 24Ac with a third thickness, a fourth
section 24Ad with a fourth thickness and a last section 24Ae with a
thickness unequal to the first thickness of the first section 24Aa.
Between the sections 24Aa, 24Ab, 24Ac, 24Ad and 24Ae, each having a
constant thickness over the length, transition sections 26Aa, 26Ab,
26Ac, 26Ad and 26Ae with variable thickness over the length are
provided. The second blank 22B is designed symmetrically to the
first blank. The second blank 22B is followed by a further first
blank 22A, and so on. The rectangular blanks 22A, 22B shown here
are also produced by simply cutting the strip material 3 brought
into the correct position from the feeds 15, 17 by a simple cut,
for example using a cross-cutting shear.
[0056] FIG. 7 shows an exemplary apparatus 2 for separating
flexible rolled strip material in a modified embodiment. This
corresponds to a widest extent to the embodiment shown in FIG. 1,
so that reference is made to the above description with regard to
the common features. The same and/or modified components are
provided with the same reference signs as in FIG. 1. This apparatus
2 as shown in FIG. 7 can be operated using the same procedure
described above in connection with FIG. 2.
[0057] The only difference in the present embodiment is the design
of the separating device 19, which in this case comprises a
form-cutting tool, in particular with a strip separating tool. The
form-cutting tool is designed to cut a form cut blank 22
corresponding to the target contour out of the strip material 3.
Depending on the component to be manufactured, one or more form cut
blanks 22 can be cut out of strip material 3 in one operation of
the form cutting tool. The separating device 19 can be designed as
a punching tool, as shown in greater detail in FIG. 9, with a lower
tool part 29 and an upper tool part 30 movable relative thereto to
make a contoured cut. In addition, the separating device can have
an integrated strip separating tool that separates a blank from the
strip. The cutting sequence can be selected as required, i.e. first
cutting a blank from the strip, then form cutting of the blank, or
separation cutting and form cutting simultaneously, or first form
cutting from the strip and then separation cutting from the strip.
Analogous to the embodiment with cross-cutting shears, the present
embodiment with form-cutting tool also provides an exact
positioning of the form cut blank 22 to be cut out, relative to
tool 19 by the feed units 15, 17. The cutting tool may have a
cutting line deviating from a perpendicular to the strip edge,
which may be straight, oblique or curved. Depending on the shape of
the form cut blanks to be cut, sloping or curved cutting lines can
be used to reduce punched scrap, as the case may be.
[0058] The feed units 15, 17 are control connected to the form
cutting tool 19 in such a way that the strip material is fed in the
desired length up to a reference point 32, respectively a reference
plane at the form cutting tool 19. In particular, it is provided
that the form cutting tool 19 be aligned exactly with respect to
the press table 31 and be positioned and/or fixed exactly by means
of positioning means, such as fitting pins or fitting cones for
example.
[0059] FIG. 8 shows a form cut blank 22, which can be cut out using
the punching tool 19 as shown in FIG. 7. The form cut blank 22 is
characterized in that it has a defined circumferential contour 27.
The contour of the sheet blanks 22 to be cut out of the strip
material 3 is arbitrary and can be configured individually
according to the geometric specifications. As an alternative to the
punching tool described above, a beam cutting device is
particularly suitable for producing a form cut blank 22, for
example a laser beam cutting device, which can be moved along
several axes, namely at least in the feed direction and in the
transverse direction and, as the case may be, in the vertical
direction of the strip material. The form cut blank 22 has sections
24a, 24b, 24c, 24d with different thicknesses (plateaus) and
intermediate transition sections 26a, 26b, 26c (ramps). FIG. 8
shows the reference edge 32 on which the strip material 3 is
positioned in the separating device 19 to produce the form cut.
[0060] FIG. 9 shows an exemplary separation sequence for a form cut
blank 22 from FIG. 8 by the form cutting tool 19, which is shown
dashed here. Of the form cutting tool 19, the lower tool part 29,
which is positioned on the press table 31, and the upper tool part
30 can be seen. For the cutting process, the strip 3 is advanced to
a reference separating edge 32 according to the calculation of the
feed unit 15, 17. Then, the form cut blank 22 is cut out by moving
the upper part 30 to the lower part 29. The specifically shown
example sequence comprises an OK ("i.O.") form cut blank 22,
followed by an OK ("i.O.") blank portion 22 to be cut out, followed
by two not OK ("n.i.O.") blank portions 28, 28', a further OK
("i.O.") blank portion 22'', a further not OK ("n.i.O") blank
portion 28'', and a further OK ("i.O.") blank portion 28'''. The OK
("i.O.") blanks 22, 22', 22'', 22''' are stacked by means of a
stacking system (not shown). The not OK ("n.i.O.") portions 28, 28'
are automatically scrapped.
[0061] With the apparatus and, respectively, process described
above, it is possible to uncoil coils 4 of flexibly rolled strip
material 3, straighten them, examine the provided sheet thickness
profiles for conformity with the sheet thickness tolerance and
carry out an OK/not OK evaluation. By this, the strip 3 is divided
into feed lengths, which are positioned exactly under the
separating edge of the separating device 19. The cutting device 19
then cuts the feed lengths from the strip. In the case that the
feed length is "OK" (i.O.), the rectangular or form cut blank is
fed for further processing. If it is a feed length that is "not OK"
(n.i.O."), it is sorted out and scrapped.
LIST OF REFERENCE SIGNS
[0062] 2 apparatus [0063] 3 strip material [0064] 4 coil [0065] 5
coiler [0066] 6 straightening unit [0067] 7 inlet driver [0068] 8
take-off roller [0069] 9 buffer device [0070] 10 uncoiling and
straightening group [0071] 12 separating group [0072] 13 level
sensor [0073] 14 thickness measuring device [0074] 15 first feed
device [0075] 16 first length measuring device [0076] 17 second
feed device [0077] 18 second length measuring device [0078] 19
separating device [0079] 20, 20' measuring wheel [0080] 21, 21'
support wheel [0081] 22 blank [0082] 23 end [0083] 24 sections
[0084] 25 end [0085] 26 transition section [0086] 27
circumferential contour [0087] 28 not OK (n.i.O.) range [0088] 29
lower tool part [0089] 30 upper tool part [0090] 31 press table
[0091] 32 reference edge [0092] A distance [0093] B trigger signal
[0094] D thickness [0095] E plane [0096] L length [0097] M torque
[0098] P profile [0099] R direction [0100] S step [0101] VL feed
length
* * * * *