AT512098A2 - A method of calculating the initial diameter of a web winding on a roll after a roll change - Google Patents

Abstract

The invention relates to a method for calculating the initial diameter (A) of a web winding (102) on a roll (103) after a roll change, wherein the web (101) from the roll (103) unwound and a transport device (110) of the processing machine with a Web transport speed (v2) or a transport device (110) of the processing machine with a web transport speed (v2) and wound on the roll (103), wherein the roller (103) with a variable winding speed (v1) rotates, in the context of a control of a Controlled variable (xist) is specified as a manipulated variable, wherein the output diameter (D1) of the web winding (102) on the roll (103) after the roll change is calculated from a change in the controlled variable (xist) during a predetermined period taking into account winding speed (v1) and web transport speed (v2) during this period.

Description

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A method of calculating the initial diameter of a web winding on a roll after a roll change

description

The present invention relates to a method for calculating the initial diameter of a web winding on a roll after a roll change as well as a computing unit for its implementation.

Although reference will be made hereafter mainly to web-fed printing presses and their winding devices, the invention is not limited thereto, but rather directed to all types of machine tools in which a web or web is unwound or rolled up. However, the invention is particularly applicable to web-fed printing machines, such as e.g. Newspaper printing machines, commercial printing machines, gravure printing machines, packaging printing machines, digital printing machines or securities printing machines, as well as other web-processing machines, e.g. Pouch machines, envelope machines or packaging machines, can be used. The web can be made of paper, cloth, cardboard, plastic, metal, rubber, in foil form, etc.

State of the art

In the prior art, web processing machines such as e.g. Printing machines, known in which a winder (winder or unwinder) comprises a roll changer to replace overhanging material (i.e., a wound web) on a first roll with a new material roll during operation, or vice versa. A winding device with roll changer usually has two pivotable about a pivot axis pivot arms, each carrying a roll for winding or unwinding of a web. The swivel arms can freely move around the ύιλά-Λ by means of an electric drive. .:.

Swivel axis to be pivotable to allow the roll change. Such a roller changer is shown in EP 2 050 699 A2, to which reference is made for further technical details of the underlying winder. There, a method is disclosed for determining an actual diameter of the roll during the pivoting movement. 5

A role change takes place either " flying " instead of, i. rotate the first and second rollers and the webs are connected, usually glued by means provided on the web of the second roll of adhesive strip, or standing at a standstill, that is, first and second roles, while the webs are connected. In order to maintain operation, in the second case there is a web store (usually a so-called dancer) which is emptied during the connection process.

In normal processing, one of the rolls is placed over the web in connection with the machine, the web being either taken out of the machine at the web outfeed (" outfeed ") at a web transport speed and taken up on or off the reel

Roll is unwound and the infeed ("Infeed") of the machine is supplied at a web transport speed. The role is driven by a drive, usually a center drive, peripheral drive or similar, with a winding speed. The diameter of the wound web on the roll is constantly changing during the winder operation and is determined by a winding control, for example, by means of the speed ratio between the winding speed and the web transport speed. The web transport speed is taken off at a reference axis, in particular a web transport axis, the reference axis defining a reference to the transport speed of the web. The reference axis can also be a simulated or emulated axis (so-called virtual axis). The winding speed is usually specified in the context of a control (ie in the closed loop) or a control (ie in the open loop) as a manipulated variable, eg. In the context of a Tänzerlageregelung, a drive torque control, a speed or speed control, 30 traction control or a Traction control, as will be explained below with reference to Figures 1-3. It should be emphasized that in the context of this invention, both closed-loop (closed-loop) control and open-loop ("open-loop") control are referred to as " control " and both the control variable of a control and the size of a control to be controlled as " controlled variable " be designated.

However, a diameter calculation is not possible immediately after a roll change, since the rules mentioned are disturbed by the roll change. It is therefore common in the art to manually input the output diameter of the new roll into the computing unit, which is error prone, or to measure through expensive equipment (e.g., photointerrupters), which is expensive. However, knowing the initial diameter is necessary in order to be able to specify a suitable (initial) winding speed until a conventional diameter calculation works again.

It is therefore desirable to have a simple way of determining the starting diameter of a roll after a roll change.

Disclosure of the invention

According to the invention, a method is proposed for calculating the initial diameter of a product web winding on a roll after a roll change and a computing unit for carrying it out with the features of the independent patent claims. Advantageous embodiments are the subject of the dependent claims and the following description.

Advantages of the invention

The invention provides the ability to calculate the exit diameter of a new roll in the machine or its control device. A manual and error-prone input by the operator or a complex measurement is not necessary. This leads in particular to time and cost savings.

In the context of the invention, the initial diameter of the goods winding is determined from variables which are usually already known in the machine or can be easily determined, namely a change in the controlled variable during a predetermined period taking into account the winding speed and web transport speed during this period. As a controlled variable is preferably a dancer position, a drive torque, a speed or a tangential speed of the roller drive or a tensile force between the role and collection or withdrawal plant.

An arithmetic unit according to the invention, e.g. a control device of a winding device (for example, a printing press) is, in particular programmatically, configured to perform a erfmdungs-related method. 5

Also, the implementation of the invention in the form of software is advantageous because this allows very low cost, especially if an executing processing unit is still used for other tasks and therefore already exists. Suitable data carriers for providing the computer program are, in particular, floppy disks, hard disks, flash memories, EEPROMs, CD-ROMs, DVDs and the like. It is also possible to download a program via computer networks (Internet, intranet, etc.).

Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawings. 15

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination indicated, but also in other combinations or in isolation, without departing from the scope of the present invention, 20

The invention is illustrated by Ausführungsbei play in the drawing shown schematically and will be described below in detail with reference to the drawings. 25 figure description

1 shows a schematic representation of a first winding device for use with a preferred embodiment of the invention, FIG. 2 shows a schematic representation of a second winding device for use with a preferred embodiment of the invention,

FIG. 3 shows a schematic representation of a third winding device for use with a preferred embodiment of the invention,

FIG. 4 shows a schematic representation of a winding device with variables which are relevant for the determination of the exit diameter according to a preferred embodiment of the invention. 5

FIGS. 1 to 3 first describe ways of operating a winding device which are known from the prior art and which are similar to the unwinding of a web from a roll and the feeding of the unwound web into a processing machine or for the removal of the web from the processing machine and 10 are suitable for winding on a roll. In the figures, the same or the same elements are provided with the same reference numerals and will not be described repeatedly.

For reasons of simplification, the figures will be explained with reference to an unwinding process.

However, this is purely illustrative and not restrictive. 15

FIG. 1 shows a first embodiment of a winding device 100 suitable for the invention. It is a very simple embodiment, in which a web 101 is unwound from a web winding 102 and fed to a collection process 110 as a transport device of the processing machine. The winding 102 is located on a roller 103, which is driven by a drive (usually an electric motor, not shown). In the same way, the feed train 110 is driven (usually also by an electric motor, not shown). In this way, the infeed system specifies a web transport speed V2 and the reel a winding speed vj (the velocities v describe tangential velocities with which the web 25 is moved, the conversion to a rotational speed is of course). From the speeds vj and v2, a web tension Fn is produced in the web 101 between the reel 103 and the infeed 110. In the illustrated embodiment, the web tension Fi2 is regulated in the open loop without feedback as a controlled variable by the winding speed of a computing unit 150 as the manipulated variable V | is specified or influenced. The 30 relevant to the invention change in the controlled variable "web tension". can be determined indirectly via a change of the actual drive torque of the drive of the roller 103 here. The actual drive torque can be determined, for example, via the current consumption, as is known in the prior art. 6M4

A further improved embodiment is shown in Figure 2, in which the winding device 200 has a return of the web tension Fn, so that a closed-loop control is realized. For measuring the web tension Fl2, a so-called load cell 210 is provided, as is known in the art. 5

An embodiment 200 comparable embodiment includes a control of the drive torque of the drive of the roller 103. In this case, an upper torque threshold value of the drive is usually specified. A control of the drive torque corresponds in principle to a regulation of the web tension force. Another comparable embodiment of FIG. 10 holds the control of a tangential velocity v * of the roller 103 (or the associated rotational speed).

A further improved embodiment is shown in FIG. 3, in which the winding device 300 has a dancer position control. For this purpose, a so-called dancer 310 is provided, in which a dancer roller 311 can be moved in a direction x. The actual dancer position: ¾ is transmitted to the arithmetic unit 1 SO, which is influenced by the speed V | the actual dancer position jcjst on a target dancer position xsou regulates.

The illustrated embodiment also has a draft control, which in this case, however, is not relevant to the invention. The measured by the load cell 210 tensile force F12 is transmitted to a computing unit 160, which adjusts, for example, the dancer pressure P of a pneumatic cylinder according to a control deviation.

As long as the described arrangements are active, the diameter of the winding 102 can be calculated 25 of the roller 102 by comparing the speeds v, and v2, since the

Diameter of the driven roller of the intake is known. The winding speed is then usually composed of a portion of the machine control (usually corresponding to a master axis) and a portion of the control (usually an additive set speed). The proportion of the machine control is changed depending on the current 30 winding diameter, usually by a so-called. Feinab equal (corresponds to a gear ratio). During the roll change, however, the diameter calculation for the roll to be changed is deactivated and for the new roll / winding, the diameter calculation can not yet be carried out in the usual way. In order to be able to specify a meaningful angular velocity vi during this, it is customary in the prior art to have the starting diameter of the new winding entered by the operator into the arithmetic unit or to be measured by elaborate measuring devices. 5

In the context of the invention, which is explained below with reference to a preferred Ausführungsbei-game, the output diameter can now be calculated on the basis of already known sizes. FIG. 4 shows only the elements of FIG. 3 which are relevant for the following considerations. Ln describes the length between the roller 103 in the drafting unit 110, Dx the output diameter of the winding 102, D2 the diameter of the driven cylinder of the infeed 110, Dt the diameter of the dancer roller and the actual dancer position. In the present embodiment, the total length lges of the web 101 between the reel 103 and the infeed 110 is to be determined, which depends on the dancer position (the lower the dancer roller 311 in Figure 4, the longer the web). An optionally non-rectangular geometry will be considered by the skilled person in the calculation of the total length lges. 20

From the comparison of the two velocities vi and v2, knowing the diameter Di, knowing the actual dancer position (which is the controlled variable here) and taking into account the geometric relationships, the diameters Di of the winding 102 can be calculated according to: 25 = ^ 2 " * "2 * * ώί + 0, i-iT-Dj. - £) 7. ü) L [m], x [m], D [m]

When viewed during a period of time T, a change Δχ &amp; the actual dancer position and it results from the velocities V | and v2 each rotation of the rollers by an angle Δφι or Δφ2 and therefrom: (2) 2 Αχ ^ = Δφ1 · ^ - Αφ2 · ψ • • «---8Π4- · A <p [rad], D [m], x [m] from (1) and (2) follows: _ 4 · Δχ., + Δ ©, · £),

Dl = -sa-23-2. (3) Δψι 5

Thus, the initial diameter D \ of the winding 102 can be calculated from the change Axüi the actual dancer position (= controlled variable) during the period T taking into account the winding speed vi and web transport speed v2 during this period. 10

At standstill of the web with v2 = 0 or Δφ2 = 0, the following simplification results: A = 4-4 ^ - (4) Δ <p,

In this case, the diameter can be determined by rotating the roller 103 and observing the effect on the controlled variable. Alternatively, it is also possible to change the nominal value for the controlled variable (here dancer position) at standstill and to determine the change of Δφι after the compensating process of the controller has taken place.

An analogous simplification for vi = 0 or Δφι = 0 and v2> 0 or Δφ2> 0 (roll 103 at standstill and infeed 110 in motion) can also be derived and used. 20

The following explains how the output diameter Di of the winding 102 is determined in the case of an embodiment according to FIGS. 1 and 2.

From the Hooke's law a change AF of the web tensile force results from a change Δε of the web elongation: AF = E-εε (5) F [N] j modulus E [N / m2], cross-sectional area A [m2], e [%]

E-modulus and cross-sectional area can be determined and assumed to be constant. 30 The following applies to the change in the aether extension: • m * · • · • -9Π4- * *

a A A A (6) Δψ ^ -γ-Δψι'γ l, tot F [rad], r [m], 1 [m], x [m] 5

With (5) and (6): A = (jrj * + δ ^ 2 · A] Ap, (7) 10

Thus, the output diameter Di of the winding 102 can be calculated from the variation AF of the traction force (= controlled variable) during the period T taking into account the winding speed V] and the web transport speed v? be calculated during this period.

At standstill of the web with V2 = 0 or Δφ2 = 0, the following simplification results: 2-AF CA = '(8) 15 EA Δφ} In this case, the diameter can be adjusted by turning the roller 103 and observing the effect on the controlled variable be determined. Alternatively, it is also possible to change the setpoint value for the controlled variable (here, for example, tractive force, drive torque or speed) at standstill and to determine the change in A <p [p] after the compensating process has taken place. 20

An analogous simplification for vi = 0 or Δφι = 0 and v2> 0 or Δφ2> 0 (roll 103 at standstill and infeed 110 in motion) can also be derived and used.

In a sensorless winding device, for example according to FIG. 1, AF can be derived indirectly from the change ΔΜ [of the actual drive torque of the roller 103 during the time period T according to:

The result is then: (9) 25

(10) and

(11) 5 It is appropriate to choose the angular changes (and thus the change in length) relatively small in order not to damage the web and / or to drive the dancer roll or a load cell into a stop. On the other hand, the larger the angular change, the more accurate the calculation result becomes, because then errors (e.g., measurement error, noise) will be less. One way of solving this problem is to determine the starting diameter with only a small change in diameter. The only small change in angle results, for example, from a maximum permissible change in length (this can be determined since the structure of the machine is known) and the assumption that the output diameter corresponds to the largest possible diameter. In an advantageous development, a maximum permissible change in angle can be determined from the output diameter determined with only a small angular change. In a second step, the starting diameter is then more accurately determined by a larger angle change, which corresponds at most to the maximum permissible angle change.

Claims (13)

Claims 1. Method for calculating the starting diameter (A) of a fabric winding (102) on a roll (103) after a roll change, wherein the fabric (101) is unwound from the roll (103) and a roll (103) Transport device (110) of the processing machine with a web transport speed (v2) fed or a transport device (110) of the processing machine with a Bahntransportge-10 speed (¾) and wound on the roll (103), wherein the roller (103) with a variable Winding speed (vj) rotates, which is specified as a control variable in the context of a control of a controlled variable (.xFl2), wherein the output diameter (D |) of the web winding (102) on the roller (103) after the roll change is calculated from a change in the controlled variable (xü "F | 2) during a given period taking into account winding speed (vi) and web transport speed (v2) w During this period of time. 2. The method of claim 1, wherein the controlled variable a dancer position (xto), a drive torque of a drive of the roller (103), a tangential speed or a Rotationsge- 20 speed of the winding (102) or a tensile force (F | 2) in the web (101) between roller (103) and transport means (110). 3. The method of claim 1 or 2, wherein an angular change of the roller (103) and / or an angle change of the transport device (110) in the calculation of the output gear 25 diameter (D i) are taken into account. 4. The method of claim 3, wherein the setpoint for the controlled variable is changed and the output diameter (Di) is calculated from the resulting change in the control variable (xit /, F, 2) during the predetermined time period taking into account the 30 angle change of Roller (103) and / or the transport device (110) during the pre-given period of time. 5. The method of claim 3 or 4, wherein a first angular change is performed, resulting from a maximum allowable change in length of the web (101) between V · · · · · 12714'- roller (103) and transport device (110) and a maximum possible exit diameter results. 6. The method according to claim 5, wherein a first initial diameter is calculated taking into account the first angular change, a second angle change is carried out, resulting from the maximum permissible change in length of the web (101) between the roller (103) and the transport device ( 110) and the first exit diameter and a second exit diameter is calculated taking into account the second angle change. 10 7. The method according to any one of the preceding claims, wherein the length of the web (101) between the roller (103) and transport means (110) in the calculation of the output diameter (Di) is taken into account. 8. The method according to any one of the preceding claims, wherein a modulus of elasticity and a cross-sectional area of the web (101) between the roller (103) and transport means (110) in the calculation of the output diameter (DQ be considered. 9. The method according to any one of the preceding claims, wherein the roll change in Still-20 stood the processing machine is performed. 10. The method according to any one of the preceding claims, wherein during the predetermined period of time, the winding speed (vi) is zero and the web transport speed (v2) is greater than zero. 25 11. The method according to any one of claims 1 to 9, wherein during the predetermined period of time, the winding speed (vi) is greater than zero and the web transport speed (v2) is zero. 12. The method according to any one of the preceding claims, wherein the processing machine is a printing press, a web press, newspaper printing press, a commercial printing press, a gravure printing machine, a packaging printing machine, a digital printing press, a securities printing machine, a bag machine, an envelope machine or a packaging machine. • * • Μ • · * • • 137 137 137 137 137 137 13714 · - * 13. Arithmetic unit which is adapted to perform a method according to any one of the preceding claims. Oct 5, 2012