EP1681255A2 - Roll changer for feeding a material web - Google Patents

Abstract

The reel changer for the feed of a material web (02) has at least one rotatably mounted reeling-off residual reel (06) and at least one follower reel (07). An oscillation sensor (12) measures oscillations encountered radially to the rotational axis (10) of the residual reel and transmits a measurement signal representing the oscillations to a computing unit. The oscillation sensor measures the distance between the generated surface of the residual reel and the oscillation sensor. An independent claim is included for a method for the operation of a reel changer in which a minimum value and/or a maximum value of the oscillation amplitude is determined in the computing unit, and a control signal sent out by the computing unit if the predetermined value is exceeded or not reached.

Description

The invention relates to a roll changer for feeding a material web according to the preamble of claim 1.

Reel changers are used on printing machines and serve to supply the material web used as printing material. As a rule, paper webs are used. The material web is wound on a roll of material and runs from this roll of material.

So that the exhaustion of a material web does not require the entire printing press to be stopped, it is known to carry out a so-called flying reel change. For this purpose, a new roll of material is clamped in the roll changer, where, for example, appropriate splices are prepared for connection to the running roll of material. During the flying reel change, this new material reel is then accelerated to a peripheral speed which corresponds to the web speed of the web of material unwound from the ending residual reel. In the actual web change of the web start of the new material web is connected to the expiring web of the remaining role and separated at the same time the residual roll of material web. The web start of the new material web is drawn in this way from the old web into the press and a machine downtime is avoided.

Depending on the remaining thickness of the material and the design parameters of the running roll of material, this has a changing vibration behavior and a also dependent on the remaining material on the material roll amount of resonance speed. Especially at relatively large Web widths and very high web speeds may, according to the manufacturer, fall short of a certain residual thickness to critical vibration states in the range of the intrinsically critical resonance speed of the sleeve. To avoid these critical vibration states, it is therefore often necessary that the web speed must be shut down when falling below a certain residual thickness of the roll of material or that the roll change must be made well before the actual end of the expiring web of the remaining role. Both measures increase the printing costs in an undesirable manner.

EP 0 657 725 B1 discloses a roll carrier and a method for determining intrinsic forces and for determining the length of a material web on a supply roll in a roll carrier. By a continuous on-line weight determination, the web length of a supply and / or a residual role can be determined. Likewise, an imbalance of the supply roll can be signaled, which can be caused by incorrect clamping or a deformed supply roll.

DE 600 02 582 T2 describes a device for unwinding a paper web, wherein the shape of the cross section of the paper roll is measured by means of two laser measuring devices.

From DE 76 09 748 U1 a winding machine for films is known in which an out-of-roundness of the reel spool can be measured by optical sensors.

DE 103 21 359 B3, DE 100 44 861 A1, DE 44 41 980 A1, DE 196 14 300 B4 and DE 201 14 750 U1 disclose various measuring methods for determining deviations in shape of rotational bodies, in particular material rolls.

The invention is based on the object reel changer for maximum utilization of Creating material rolls of large web widths at maximum web speed.

The object is achieved by the features of claim 1.

The achievable with the present invention consist in particular that material rolls can be rolled in reel changers with constant web speed up to a minimum residual roll diameter and the flying web change can also be performed at the normal web speed, which allows the printing process continuously at maximum capacity of the machine capacity to drive.

A measurement of the vibrations on the residual rolls makes it possible to stop the residual roll when critical vibration conditions are reached. Also can be determined from the vibration behavior of the residual role of the residual roll diameter to initiate, for example, a flying role change at a predetermined value. With the method and the device for measuring the vibrations, it is also possible to measure new web widths and types of sleeves during operation in the reel changer in order to determine their maximum utilization and the maximum possible web tension.

The invention is based essentially on the finding that, contrary to the manufacturer's instructions for the oscillation amplitudes of different types of sheaths and web widths, substantially lower oscillations of the supply rolls in the region just before the change of the material webs can be achieved. It has been found that the web pull in the reel splicer acts as an additional bearing which extends over the entire roll width and thereby greatly dampens the vibrations of the roll of material, thereby providing the above advantages.

The measurement of the vibrations is preferably carried out by optical displacement measuring systems, which allow a non-contact measurement. A preferred measuring system consists of a laser-optical triangulation sensor and a controller as an evaluation system. In this case, a point of light is projected onto the measurement object, here preferably the roller surface, and diffusely reflected there. This point is imaged via a lens on a position sensor. The sensor provides a position-dependent signal that is proportional to the measurement path.

For this purpose, a sensor is positioned on the device so that a laser beam emitted by the sensor impinges almost perpendicular to the surface of the roller. The sensors are preferably mounted on the roller carrier, the center of the roller being preferred as the measuring position, since the greatest vibration amplitudes are to be expected here.

It has proved to be advantageous to provide a second and, if necessary, further sensors on one or both clamped roller sides. As a measure of the dynamic deflection of the roller, these sensors provide a distance signal which is acquired and processed by an evaluation system. The signal may be digital or analog, and either passed to a computer system which controls, for example, the entire system, or fed as an analog signal to an evaluation circuit. The evaluation circuit can at the corresponding signal levels, z. B. due to excessive deflection, excessive vibration or imbalance of the roll of material, a roll stop (especially emergency stop) or initiate a role change.

When using multiple distributed over the web width sensors, the evaluation system can deliver a difference signal in a further embodiment, which is adjusted to any disturbances, such as concentricity error. This is particularly advantageous for large roll widths. For this purpose, the distances between sensor and roller surface measured in the middle of the roller and on the sides of the roller are continuously determined and the oscillation amplitude is determined by the evaluation system from the difference signal from the sensors.

Since the oscillation amplitude is largest in the center of the roll and smallest at the clamping points, the exact oscillation can be formed from the difference of the two distance signals. Immanent concentricity errors inherent in the respective roll of material, which result in a change in distance between the sensor and the roll surface, but do not indicate excessive vibration, can be filtered out at several points along the roll of material by the multiple detection. Since the oscillation amplitudes are very small, this difference measurement determines the oscillation amplitude more accurately and avoids the risk of a "false alarm".

For a later evaluation and analysis of the vibration states, it may be useful to record the time shortly before and after the change of lane, since here the highest vibration paths can occur. For this purpose, the evaluation system can receive a trigger from the cutting blade, so that a certain amount of time can be recorded before and after the roll change. If, for example, new types of rolls are measured, then in evaluation of the records, the web tension can be gradually increased and the residual roll diameter can be reduced until the optimum utilization is achieved. During operation on the reel changer, the vibration path monitoring is then preferably used to control the operation and to avoid critical operating states, wherein the evaluation system can trigger the trigger when exceeding or falling below predefined values of the vibration amplitudes, which are further processed by the system.

In principle, it is sufficient to monitor the vibrations of the respective residual roll with only one sensor in the position preparatory to the roll change. It is advantageous, however, if the device provides a separate sensor for each roll holder in a roll changer. Thus, the vibration of the running material roll, but also the vibration of the roll change to be accelerated roll of material can be monitored. In addition, the reorientation of the sensor after a roll change on the then expiring roll of material deleted.

A portable device for use on various roll carriers can also be used to measure the vibrations, for example to measure new types of reels, new role carriers or new recordings on reel splitter. For this purpose, a device that contains a displacement sensor and an evaluation system, for example, be placed under the roll of material. Then, the measurement can be carried out in the regular operation of the reel changer, and with the obtained measurement results, the web tension during roll change and the minimum possible residual roll thicknesses can be optimized.

In the prior art, there are other ways to measure vibrations without contact: electromagnetically, acoustically and as ready called optically. Fiber optic sensors, interferometers, and laser Doppler vibrometers may also be mentioned here as usable optical measuring methods.

If, when measuring a new type of reel or a new roll width, it becomes apparent that the vibration amplitudes become too great at maximum web speed, additional support means may be applied to the reel to dampen the vibrations.

With the high web-pull speed achieved in this way with low residual roll diameter, the system must be monitored for a possible web break, because if the web train suddenly fails due to a web break, the vibration amplitude can quickly reach 10 times and more, jeopardizing the entire system , If the residual role even comes into resonance, it comes to a dangerous rocking of the vibration. It must also be ensured that the residual rolls are not excited by a "snap-back" effect to high oscillation amplitudes. In the case of a web break, it must therefore be ensured that the hazardous vibration states do not occur. The machine must be stopped.

For this purpose, a preferably optical sensor, such. As a light barrier, attached near the roll of material that provides a web break signal in a web break, which is used to decelerate the remaining role and possibly to shutdown the machine.

An embodiment of the invention is illustrated in the drawings and will be described in more detail below.

Fig. 1

einen Rollenwechsler in Seitenansicht;

Fig. 2

eine vereinfachte Querschnittsdarstellung eines Rollenständers mit Schwingungssensoren;

Fig. 3

eine schematische Darstellung eines Rollenträgers;

Fig. 4

eine vereinfachte Diagrammdarstellung der Schwingwege einer Restrolle.

Show it:

Fig. 1

a roll changer in side view;

Fig. 2

a simplified cross-sectional view of a roll stand with vibration sensors;

Fig. 3

a schematic representation of a roller carrier;

Fig. 4

a simplified diagram representation of the vibration paths of a residual role.

In Fig. 1, an embodiment of a roll exchanger 01 for feeding a web of material 02, in particular a paper web, is shown schematically in a printing machine, not shown. On roll splitter 01, a roll carrier 04, which is pivotable about a pivot axis 03, is provided, which is formed by two support arms 04 arranged one behind the other in the image plane. At the free ends of the roller carrier 04 are each mounted opposite each other recordings, between which material rolls are clamped on the paster 01. On reel changer 01 in the process state shown a running material roll 06, z. B. Restrolle 06 and a prepared for the flying role change, new roll of material 07 clamped. The roller carrier 04 has been previously pivoted to the position shown in Fig. 1, so that the expiring residual role 06 required for the flying reel change Takes position. To support the new roll of material 07 and to transfer the driving forces (acceleration and brake stop) in the loading position, a support belt 08 is pressed from below against the circumference of the new roll of material 07. Before the roll change, the new roll of material 07 must be accelerated until its peripheral speed essentially corresponds to the web speed of the material web 02 running from the remaining roll 06. The material web of the new roll of material 07 is connected to the roll of material with the running web 02 of the remaining rollers 06, in particular glued. Since the person skilled in the principle of operation of a roll changer 01 is known, can be dispensed with a more detailed description.

On the pivot axis 03 of the roller carrier 04, which runs parallel to the axes of rotation 10 of the material rolls 06 and 07 are in the embodiment shown, two sensors 12, z. B. vibration sensors 12 mounted (shown in Fig. 1 only schematically), so that in each case a measuring beam 14 approximately in the middle of the roll, impinges substantially perpendicular to the roll surface. For this purpose, reference is made in particular to the illustration in FIG. 2.

In Fig. 2 is a simplified cross section through the roller carrier 04 in the roller or web center is shown. Two vibration sensors 12 are preferably mounted on the pivot axis 03 at the level of the center of the track, so that a measuring beam 14 emitted by the vibration sensor 12 impinges almost perpendicular to the roll of material 06 or 07. From there it is reflected and converted by a position sensor contained in the vibration sensor 12 into a signal which is transferred to an evaluation system. By an appropriate assembly ensures that the relative position of the vibration sensors 12 remains unchanged to the material rolls 06 and 07, when the rolls of material 06; 07 are pivoted when changing roles. Thus, an uninterrupted measurement of the vibrations is possible.

As close as possible to the running material roll 06 is a sensor 16, z. B. a Bahnrisssensor 16, which may be a photoelectric sensor, photocell or the like, which gives a signal to brake the residual role 06 or to stop the system when no more paper web is detected by sensor 16. Preferably, two web break sensors 16 are also used here, which are fixedly mounted on the roller carrier 04, so that each roll of material 06; 07 a sensor 16 is assigned, which is pivoted with the flying role change. The Bahnrisssensoren 16 are also connected to the evaluation system and the entire system.

Fig. 3 shows a simplified representation of a part of a roller carrier 04 with a running material roll 06, which is clamped by means of clamping cones 17 in the support arms 04 of the roller carrier 04. On the pivot axis 03, distributed over the web width, three vibration sensors 12 are mounted, the measuring beams 14 impinge approximately perpendicular to the rotating about the axis of rotation 10 running material roll 06. A first of the three vibration sensors 12 is arranged approximately in the middle of the track, where the highest vibration amplitudes are to be expected. The two other sensors 12, however, are positioned at the edges of the running material roll 06, where the roll of material 06 is clamped in the clamping cones 17. In a modified embodiment, a second sensor 12 is provided only at one edge of the roll of material 06. If one considers not only every single sensor signal supplied by the sensors 12 but also the differences between these signals, non-vibration-based distance changes between the sensor 12 and the material roll 06 can be eliminated. This makes it possible to take into account less or not at all the distance changes resulting in particular from concentricity errors, which are of little significance for the vibration behavior, if a reduction of the speed of the material roll 06 has to be decided on the basis of the sensor signals. A quick stop or deceleration of the machine is only required if there is a risk of machine damage due to increased vibrations. Concurrent errors attributable to run-out errors of the machine can by this measuring principle be avoided.

With the vibration measurement on the residual roll 06, it is possible to make better use of the material of the residual roll 06 and also to carry out the roll change at high web speeds.

This will be understood from the simplified diagram representation in Fig. 4, in which the envelopes of recorded vibration paths are reproduced. The two dashed lines 18 show the course of the vibration paths of a rotating rest roller 06 again, if this is not damped by the train. It can be seen that the swing path increases with time from about 1.3 to 2.3 mm, although the rotational speed of the residual roll 06 does not increase (i.e., no further unwinding of material). The measured values enclosed by the envelope 18 were recorded on a residual roll 06 having a diameter of 188 mm (including the remaining material) and a width of 4,290 mm. The speed corresponded to a web speed of 15.5 m / s. These measurement results also explain the manufacturer's specifications, which mean that a considerable amount of material must always remain on the remaining roll 06 when changing rolls in systems with high web speed, since the oscillation paths of the residual roll 06 must not become too great if the roll changer 01 is not damaged should.

A comparable rocking of the vibration paths can occur in the event of a web break. In order to prevent this, it is important in this case to stop the machine as quickly as possible. For web crack detection, the web tear sensor 16 described above, which is to be installed as close as possible to the remaining roll 06, is used.

In comparison, the continuous drawn envelope 20 shows the oscillation path of the residual roll 06 during the continuous unwinding of the material web 02, so that a continuous web train acts on the rest roller 06. It can be seen that the Web tension exerts a strong damping effect on the vibration behavior of the rest roller 06. Although an increase in the vibration path would actually be expected with the passage of time, despite decreasing residual thickness of the material remaining on the remaining roller 06 and concomitant increase in the rotational speed of the rest roller 06, the oscillation travel is reduced if the high web speed is maintained unchanged. The speed of the remaining roller 06 during the symbolized by the envelope 20 measurement rose from 20 to 24.4 Hz. This can be explained by the fact that the weight load of the remaining roll 06 by the paper decreases during the unwinding process. The curves drawn in FIG. 3 show that the oscillation of the residual roll 06 without web draw is about 9 times greater than with web draw.

With consistent application of this knowledge, it is possible to further develop the rolls of material in a sustained web train than before and thereby maintain unchanged even high web speeds of more than 12 m / s or even 14 m / s when changing rolls. A braking of the material web for the roll change is no longer necessary.

The correct understanding of the oscillatory behavior of the running residual roll can also be used to initiate the roll change depending on the actually measured vibrations. This allows role-specific differences to be automatically taken into account so that every roll of material can be optimally handled without the risk of damage to the roll changer.

The width of the material rolls 06; 07 can be larger than 2 m. The width of the material rolls 06; 07 can be larger than 4 m.

An inner diameter of a material carrying the sleeve can be between 70 and 80 mm. An inner diameter of a material carrying the sleeve can be between 140 and 160 mm.

01

Rollenwechsler

02

Materialbahn

03

Schwenkachse

04

Rollenträger, Tragarm

05

-

06

Materialrolle, Restrolle

07

Materialrolle, neu

08

Stützgurt

09

-

10

Drehachse

11

-

12

Sensor, Schwingungssensor

13

-

14

Messstrahl

15

-

16

Sensor, Bahnrisssensor

17

Spannkonus

18

Hüllkurve der Schwingwege der Restrolle ohne Bahnzug

19

-

20

Hüllkurve der Schwingwege der Restrolle mit Bahnzug

LIST OF REFERENCE NUMBERS

01

reelstands

02

web

03

swivel axis

04

Roller carrier, support arm

05

-

06

Roll of material, remaining roll

07

Material roll, new

08

Support Belt

09

-

10

axis of rotation

11

-

12

Sensor, vibration sensor

13

-

14

measuring beam

15

-

16

Sensor, web tear sensor

17

Spannkonus

18

Envelope of the vibration paths of the remaining roll without web tension

19

-

20

Envelope of the vibration paths of the residual roll with web tension

Claims (19)

Reel changer (01) for feeding a material web (02), in the receptacles of which at least one residual roll (06) and at least one successor roll (07) prepared for reel change are rotatably mounted, characterized in that a vibration sensor (12) extends radially to the axis of rotation ( 10) of the residual roll (06), and that the vibration sensor (12) transmits a measurement signal representing the oscillations to an evaluation system. Reel changer according to claim 1, characterized in that the oscillation sensor (12) is arranged to measure the distance between the lateral surface of the residual roll (06) and the oscillation sensor (12). Reel changer according to claim 1, characterized in that the vibration sensor (12) is a first vibration sensor (12), and that the arrangement further comprises at least one second vibration sensor (12) that the evaluation system determined the difference of the two of these vibration sensors (12) Determines vibration paths and further processed only this difference as the actual vibration path of the residual role (06). Reel changer according to claim 1 or 3, characterized in that the vibration sensor (12) is arranged approximately in the middle of the residual roll (06). Reel changer according to claim 3, characterized in that the second vibration sensor (12) is arranged on the clamped edge of the remaining roll (06). Reel changer according to claim 3, characterized in that on both edges of the residual roll (06) second vibration sensors (12) are arranged. Reel changer according to claim 1, characterized in that the evaluation system is a release for the roll change when the measured vibration amplitude of the measuring system falls below a predetermined limit. Reel changer according to claim 1, characterized in that the detection of the vibration amplitude is effected by a non-contact optical path measurement. Reel changer according to claim 8, characterized in that the detection of the oscillation amplitude is effected by a laser-optical path measurement according to the triangulation measurement principle. Reel changer according to Claim 1, characterized in that a web tear sensor (16) monitoring the material web (02) is arranged, which emits a web break signal to the evaluation system when the material web (02) travels, whereupon the evaluation system brakes the remaining roll (06) , Reel changer according to Claim 1, characterized in that the roll changer (01) does not reduce the web speed of the outgoing material web (02) of the residual roll (06) prior to bonding to the material web of the new material roll (07). Reel changer according to claim 11, characterized in that the web speed during roll change is more than 12 m / s, in particular more than 14 m / s. Reel changer according to claim 1, characterized in that the width of the rolls of material (06; 07) is greater than 2 m. Reel changer according to claim 1, characterized in that the width of the rolls of material (06, 07) is greater than 4 m. Reel changer according to claim 1, characterized in that an inner diameter of a material-carrying sleeve is between 70 and 80 mm. Reel changer according to claim 1, characterized in that an inner diameter of a material-carrying sleeve is between 140 and 160 mm. Reel changer according to Claim 1, characterized in that the evaluation system reduces the web speed if the oscillation amplitude measured by the measuring system exceeds a predetermined limit value. Reel changer according to claim 1, characterized in that each roll receptacle of the roll changer (01) is associated with its own vibration sensor (12). A method of operating a reel changer according to claim 1, characterized by further comprising the steps of: - Specification of a minimum value and / or maximum value of the oscillation amplitude in the evaluation and - Output of a control signal by the evaluation when exceeding or falling below the predetermined values.

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