AT509780A2 - PROCESS FOR VIBRATING VIBRATIONS - Google Patents

Description

Method for damping vibrations in rewinders

The invention relates to a method according to the preamble of claim 1.

As is known in the art, two different methods can be distinguished in the active control of vibrations (CR Filler, SJ Elliot & PA Nelson: Active Control of Vibration, Academic Press, London, 1997, pages 59-111, 185-221 ): Feed-forward and active feedback vibration damping.

US 2004/0108405 discloses a method for damping vibrations in rewinders, wherein an active feedback damping is provided.

In active feedforward dampening of oscillations, a reference signal of directly primary structure-oriented forces {= where the forces directed to the structure exclude the forces of actuators used in damping) is measured, such as the rotational frequency of a rotating roll or roll, or In the best case, a primary force itself. By a calculation algorithm of this measured force or the reference signal, the forces of an actuator (of actuators), i. H. Calculating secondary forces whose purpose may be to lift primary forces (Act

• * .33146 / pt * ·· · · ♦ r ·

• * * «·» i • ·

Dampening of vibrations), or in avoiding the transmission of excitation of one part of the machine to another structure (active isolation of vibrations). Active feedforward damping does not change the mechanical properties of the system, such as mass, stiffness and damping.

In the case of active feedback vibration damping, the measurement of primary forces oriented on a structure is not required / not possible. The measured variable is a vibrational response (displacement, velocity or acceleration) of the structure caused by the sum of the primary and secondary forces. This vibrational response is selected via a selected transfer function to be an instruction for the actuator (s). The active feedback damping changes the response of the structure at resonance points, for example, increasing the attenuation.

Oscillation feed forward damping thus requires direct or indirect measurement of primary forces, which can be extremely difficult with rewinders, for example, with rewinder parts of slitter winders where there are multiple independent excitation sources (rollers, customer roles, all rotating at a different rotational frequency can, since they have different diameters, etc.). Many vibration effects of slitter 3 ....... * · · · ft · »I · *» 4 · «* · ft * * * * · ft · t · · *» 4 ** »*» 4 4 *

Rewinders are caused by the instability of the system in certain operating ranges {running speed, diameter dependence of the roller). It is known that the feedforward control can never stabilize an unstable system, i. H. that the feedforward damping of vibrations can not attenuate the oscillations caused by the instability. As the amplitude, phase or frequency of the excitation changes, the feedforward control must be adaptable to be able to respond to changes in the primary forces (for example, the rotational frequency of a growing roll continuously slows down). Finding a customizable control algorithm for a naturally non-linear slitter rewinder is challenging, if not impossible.

From the prior art, we refer to EP patent specification 1260470, which describes a feedforward control method for active vibration control, and devices for implementing it. In the method, the vibrational force, i. H. the primary force measured at a high sampling frequency. By a calculation algorithm, the displacement of the axis of rotation of either the roller or the roller is calculated from the measured primary force, whereby the displacement minimizes vibration forces. In the case of self-excited vibrations occurring on rewinder and slitter rewinder, this system will not allow the system to be 4 ..... WVpt ...

It is stabilized since this is a matter of active feed-forward damping. As an example, let us refer to a situation where there is an increase in the diameter of the role of a multi-station winder of 1 mm, i. H. a " bead " causing an increase in nip pressure which is desired to be displaced by the displacement of the axis of rotation of the take-up roll so that no dynamic component to the nip load is provided by the bead. If this is completely successful, the shape of the roll remains the same throughout the winding, and the roll must continuously make a 1mm movement to synchronize the rotation of the roll. Therefore, the method does not reduce the vibrations even in an ideal case.

From the prior art, reference is made to FI patent specification 990272, which describes an active forward vibration control device, the hydraulic structure being hydraulically assisted. A quick force required in vibration damping is provided with a special hydraulic cylinder having an element (for example, a piezo actuator) which provides rapid changes in hydraulic pressure. The measurement of the reference signal of the primary force is performed by the vibrating structure with a vibration converter. By a calculation algorithm, a control signal of the element is calculated from this reference signal, wherein the signal is the 5

dampens vibrations transmitted from the vibrating structure to the hydraulic cylinder. The method essentially corresponds to the isolation of the vibration component from the other structure. However, when proceeding according to this known method, self-excited vibrations which occur in rewinders, in particular slitter-winder, can not be stabilized.

In a slitter rewinder, a web of full web width in the longitudinal direction is cut into sub-webs, after which the sub-webs on the rewinder part of the slitter rewinder around rewind cores, for example reels, are rolled up into customer reels. In the paper industry, carrier roll and multi-station winder are used, among other things, to wind customer rolls, i. H. Partial rolls, used. In multi-station winder, the sub-web is wound around the take-up core by means of a reeling nip between the take-up roll and the formed web roll, with the take-up core of the formed web roll provided with a center drive. For carrier roll winder, the split webs are wound around rewind cores carried by two rolls or one roll and a set of rolls or two sets of rolls. In the following description and claims, the term carrier roll is used for convenience when referring to a carrier roll / set of rolls of carrier roll-up

Wicklers is taken, d. H. that both the meanings of a carrier roll and a set of carrier rolls are included. Also known from the prior art are variable geometry support roll winder wherein one or both of the support rolls supporting the roll are displaceable. In such variable geometry slitter winders, the central horizontal arrangement of the formed roll is dependent on the position of the carrier rolls relative to each other and on the diameter of the roll. In the context of rewinders, first, a small roller diameter pressure roller was used to produce the required nip load, and then, when the mass of rollers became large enough, when the pressure roller was no longer required due to the nip load, the pressure roller with the rollers was held in contact with a small load until the reel was completed to hold the reels in place so they would not become loose or fly out of the rewinder due to vibration or rebounding. The strong vibrations of a Andrückrollenträgers are often the reason that the rollers are eccentric or rectangular, whereby the vibrations are transmitted to the other parts of the winder. Also, the risk of flying out of the rollers increases when the pressure roller carrier oscillates intensely.

In practice, the most common way, known in the art, to avoid vibrations occurring in rewinders is to manually reduce the running speed, and then, when a certain point of oscillation is reached, reduce the running speed will, and the vibrations will be dampened. A problem with known arrangements is that the avoidance of vibration by changing the running speed reduces the capacity of the carrier roll winder and, moreover, the speed changes weaken the quality of the rolls, since changes in the tightness associated with speed changes cause the layers to shift out to the ends of the rolls can.

The object of the invention is to provide a method for damping vibrations in a rewinder, in particular in the rewinder of a slitter-winder.

Since the most significant part of vibration problems associated with self-excited resonant vibration reelers is that the system of nip rolls and rollers is in an unstable state under certain running conditions, active damping is well-suited for a vibration reducing process, and as it is known that active damping of feedback can increase the damping in resonant regions and thereby provide a stabilizing effect, it is the object of the invention to provide new arrangements based on the active feedback damping for damping oscillations occurring at rewinders produce .

In order to solve the above-mentioned objects and those which will come out later, a method according to the invention is characterized mainly by what is presented in the characterizing part of claim 1.

In the method according to the invention, in the active damping of vibrations in rewinders, at least one component of the system undergoes active feedback vibration damping, wherein there is at least one feedback signal, and the vibrations of one or more components of the system are measured, i. H. Motion, velocity or acceleration, and wherein the feedback signal is controlled via a transfer function to be a control signal for the actuator or actuators.

Furthermore, according to some advantageous additional features of the invention, the oscillations of carrier roll / take-up roll are advantageously damped by bearing housings mounted actuators, and / or the vibrations of a pressure roll carrier are damped using its own relief cylinders and / or the oscillations of the pressure roll carrier attenuated by an actuator between a carrier carriage and the carrier is interposed. The bearing housing can be pivoted at its one end, 9 33146 / pt • «♦» * «· · ·« · * 4 «« < I · · · * * * · and at the other end an actuator may be present. As actuators also advantageously hydraulic, pneumatic, piezoelectric or magnetostrictive actuators, and for example servomotors can be used.

According to the invention, to dampen vibrations in the winder, an active feedback damping system is used whose control is implemented so as to minimize the amplitude of movement of the vibrations by increasing the damping at resonance points by active feedback damping. Then, for example, the invention may be applied to carrier rolls and take-up rolls, wherein the actuator may, for example, be mounted under the bearing housing or on the shaft of the roll on the bearing. When damping the vibrations of a Andrückrollenträgers can be used as an actuator relief cylinder of Andrückrollenträgers and an actuator which is positioned between a carrier carriage which moves itself by means of frame guides and the Andrückrollenträger.

The use of a hydraulic cylinder as an actuator in the active damping of vibrations is a technique known per se, and the control can be implemented in many different ways, for example K, Heiskanen, J. Hakola, L. Laitinen, M. Peltola. " Vibration Suppression with Hydraulic Actuator ", The Eighth Scandinavian International 10

33146 / pt

Conference on Fluid Power (Eighth Scandinavian International Conference on Fluid Power), SICF? '03, 7-9. May 2003, Tampere, Finland.

According to an advantageous exemplary embodiment of the invention, the loading hydraulics are used in the active damping of directional vibrations. The vibration frequency range of the pressure roller carrier is usually lower than 20 Hz, typically 15-20 Hz, with hydraulics being particularly suitable for this range. The dampening of guiding vibrations of the pressure roller carrier is an advantageous exemplary embodiment of the invention, since the carrier is able to remain relatively rigid in the direction of the guide during vibrations, whereby the load of the hydraulic cylinder moves the entire carrier uniformly. Furthermore, the arrangement is extremely advantageous because it is in principle no more than a strategy of active damping control is required. Furthermore, according to an advantageous embodiment of the invention in a slitter rewinder, in the winder a Andrückrollenträger is present, the Andrückrollenträger hydraulically supported, and on the central region of the Andrückrollenträgers a vibration transducer is positioned, which is used as a feedback signal, wherein the hydraulic cylinder of the Andrückrollenträgers , which are intended for loading, can be used as actuators. 11 33146 / pt • «

The invention will now be described in more detail with reference to the accompanying figures of the accompanying drawing, on the details of which the invention should by no means be narrowly limited.

Fig. 1 schematically illustrates a feedback control arrangement.

Fig. 2 schematically illustrates a carrier roll winder.

Fig. 3 schematically illustrates a Mehrstationenauf-Wickler.

FIGS. 4A-4C schematically illustrate some exemplary embodiments of the invention.

Referring to FIG. 1, the feedback may be used as a control strategy in which the vibration velocity is measured at a point to be attenuated, and this vibration signal is passed directly to an actuator 27 via a P controller 20. The linear vibration system 20 then adds an addition to the attenuation, which is directly proportional to the magnification of the P controller, for each waveform with which the measurement of the response does not occur in the node of the mold.

In Fig. 2 is a Trägerrolleaufwickler, d. H. Carrier roller slitter rewinder is schematically shown 12 33146 / pt * ♦ * * * 4 * ·· «* ♦ * * * t ··· # * · * * * *« «* * * ·« * · In which a sub-web W is carried by carrier rolls 11, 12 carried by a roll-nip between a rear carrier roll 12 and web rolls 10 in sub-web rolls 10, and a press roll 15 is first used with small roll diameters to obtain a required one Then, when the mass of the rollers 10 became large enough, when the pressure roller 15 is no longer required due to the nip load, the pressure roller 15 was held in the rollers until the winding was completed to make the rollers 10 in their place. The pressure roller 15 is attached to a pressure roller carrier 13. Typically, in the axial direction of the roller a plurality of partial web rolls 10, d. H. Customer roles, consecutively available. At one stage, the wound up customer roles are known as a set. The direction of movement of the web W is denoted by the reference symbol SW, and the direction of rotation of the rear carrier roller 12 by the reference symbol S.

In Figure 3, a Mehrstationenaufwickler is shown schematically, in which a plurality of stations are present, with two Aufwickelstationen A, B thereof can be seen in the figure. In the winding station A, B is a web roll 10, d. H. Customer role, rolled up by means of a Aufrollwalzenspaltes between a take-up roll 17 and the web roll 10. In connection with a winding core of the web roll 10, a center drive 18 for rotating the web roll 10 is arranged. Both Aufwickelstationen A, B are with a Andrück- 13 33146 / pt

* roll 15 provided. The direction of movement of the web W is denoted by the reference SW, and the web W is guided to the winding station A, B by means of a guide roller 19.

In the exemplary embodiment of FIG. 4A, an active feedback damping of a pressure roller is shown schematically. The reference numeral 31 denotes a converter which measures the vibration velocity v, the reference numeral 32 a force converter, the reference numeral 13 a pressure roller carrier, the reference numeral 15 pressure rollers and the reference numeral 34 load cylinder of the Andrückrollenträgers 13. By means of the acceleration converter 31 the vertical vibration velocity v of the pressure roller carrier 13 is measured, and this vibration velocity is input as a correspondingly scaled amount for additional force control of the hydraulic cylinder 34.

In Fig. 4B an exemplary embodiment for the active feedback damping of a carrier or take-up roll 12, 17 is shown schematically. In the figure, reference numeral 41 refers to an actuator, numeral 42 to a fulcrum, numeral 43 to a bearing housing, and numeral 44 to a transducer which measures the vibration velocity v. By means of the acceleration converter 44, the vertical vibration speed of the bearing housing 43 of the carrier or take-up reel 12, 17 is measured, and this vibration speed is input as a correspondingly scaled amount for additional force control of the actuator 41. *** "

Referring now to Figure 4C, there is schematically illustrated an exemplary embodiment for active feedback damping of a rear roller 12 of a carrier roll slitter rewinder having a displaceable rear roller (a variable geometry slitter rewinder). In the figure, a bearing housing of the rear support roller 12 is denoted by the reference numeral 52, and its linear guide by the reference numeral 53. The bearing housing 52 is connected by means of a ball screw 54 with a pulley 55, which is further connected to a toothed belt 56 which by means of a second pulley 55 is connected to a shaft 57 of an AC servomotor 58. The motor 58 is controlled by control electronics 60 based on the measurement result of an acceleration-value converter 59. By means of the acceleration converter 59, for example, the oscillation speed v is measured, which is transmitted via the control electronics 60 to the servo motor 58 to be a moment control. The moment is directly proportional to the force directed to the bearing housing 52.

In the examples of FIGS. 4A-4C, the required force can be calculated using the following equations:

»F * * * * 33146 / pt ·· # <&lt; ···· c *« · · · · · · · «• I ·« * * *

• · · * M F = Fst + Fdynf

Fdyn ~ 5 "^ r where F is the total force,

Fst is the static force, which controls the load

Fdyn is the dynamic force, v is the vibration velocity, and g is the constant scaling factor.

The invention has been described above only with reference to some of the advantageous embodiments, but the details of which the invention should by no means be narrowly limited.

claims:

Claims (3)

.. Λ6 ............ 33146 / pt • * · «fi · · · · · · · · · .... .... .... .... .... .... .... .... .... .... ..... ...... 01 DR. FERDINAND GIBLER DR DR. WOLFGANG POTH Austin and European Patent and Trademark Attorneys GIBLER & POTH PATENTANWÄLTE Claims 1. A method for damping vibrations in rewinders for winding fibrous webs onto fibrous web rolls, in particular rewinders of longitudinal cutters Rewinders, the rewinder being a system having at least one component, the method comprising dampening active damping vibrations such that active feedback damping is applied to at least one component of the system, the method comprising oscillating one or more of the components Components of the system are measured to provide at least one feedback signal, wherein the at least one feedback signal is passed through a transfer function, so that it is a control signal for is at least one actuator of the at least one component, and wherein in the method, vibrations are actively damped by increasing the damping at resonance points by active feedback damping, characterized in that the method damps vibrations of a longitudinal-cutter-rewinder with variable geometry by a displacement device of a displaceable roller of the winder is used for damping vibrations. 17 3314 6 / pt * * * · Bf · «« «*» · · · »* * I * * · * ··« · · # · · · · · · ψ f I f · * A method according to claim 1, characterized in that in the method the movement or velocity or acceleration of one or several components in the system is measured. 3. The method according to any one of claims 1-2, characterized in that in the method the force required to dampen vibrations is calculated with equations: F = Fst + Fdyn and Fdyn = gv, where F is the total force, Fst the static force Fdyn is the dynamic force, v is the vibration velocity, and g is a constant scaling factor.