DE102011117358A1 - Method for computing output diameter of material web winding on roller of e.g. printing machine, involves computing output diameter of web winding on roller according to roller change from change in controlled variable - Google Patents

Abstract

The method involves rolling up material web (101) by roller (103). The transport device (110) of processing machine is fed with rail transport velocity (v2) or transport device of processing machine with rail transport velocity (v2) is removed. The roller is rotated with variable winding speed (v1) based on input of control variable. The output diameter of web winding (102) on roller is calculated according to roller change from change in controlled variable for predetermined time in consideration of winding velocity and web transport speed during time period. An independent claim is included for computing unit for computing output diameter of material web winding on roller.

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 in web-fed printing machines, such. As newspaper printing machines, commercial printing machines, gravure printing machines, packaging printing machines, digital printing machines or security printing machines, and other web-processing machines, such. As bag 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 are web-processing machines such. As printing machines, known in which a winding device (up or Abwickler) has a reel changer to replace outgoing material (ie, a wound web) on a first roll during operation by a roll with new material 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 pivot arms can be freely pivotable about the pivot axis by means of an electric drive to allow the roll change. Such a roll changer is in the 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.

A role change takes place either "flying", d. H. rotate 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 at a standstill, d. H. first and second roles stand 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 outfeed at a web transport speed and wound on the roll or unwound from the roll and fed into the infeed ") Is supplied to the machine at a web transport speed. The role is driven by a drive, usually a center drive, peripheral drive o. Ä., With a winding speed.

The diameter of the wound web on the roll constantly changes during the winding process 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 decreased at a reference axis, in particular a web transport axis, wherein the reference axis defines 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 as part of a scheme (ie in the closed loop) or a control (ie in the open loop) specified as a manipulated variable, eg. As part of a dancer position control, a drive torque control, a speed or speed control, a traction control or a Traction control, as explained below on the basis of 1 - 3 is explained. It should be emphasized that in the context of this invention both a control (ie in the closed loop) and a control (ie in the open control loop) are referred to as "control" and both the control variable of a control and the control variable of a control as " Controlled variable ".

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 customary in the prior art to manually input the output diameter of the new roll into the arithmetic unit, which is error-prone, or to have it measured by expensive equipment (eg photoelectric sensors), which is expensive. The knowledge of However, output diameter is necessary to be able to set 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, for. As a control device of a winding device (eg. A printing machine) is, in particular programmatically, adapted to perform a method according to the invention.

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 the provision of the computer program are in particular floppy disks, hard disks, flash memories, EEPROMs, CD-ROMs, DVDs and the like. a. m. 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.

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.

The invention is illustrated schematically by means of exemplary embodiments in the drawing and will be described in detail below with reference to the drawing.

figure description

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

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

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

4 shows a schematic representation of a winding device with sizes that are relevant for the determination of the output diameter according to a preferred embodiment of the invention.

In the 1 to 3 are first described in the prior art ways to operate a winding device, which is as it were for unwinding a web from a roll and feeding the unwound web into a processing machine or for removing the web from the processing machine and winding on a roll suitable. 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.

In 1 is a first embodiment of a winding device suitable for the invention 100 shown. It is a very simple embodiment in which a web 101 from a web winding 102 unwound and a catchment 110 is supplied as a transport device of the processing machine. The winding 102 is on a roll 103 which is driven by a drive (usually an electric motor, not shown). In the same way, the feed mechanism 110 (usually also powered by an electric motor, not shown). In this way, the infeed system specifies a web transport speed ν ₂ and the reel a winding speed ν ₁ (the velocities ν describe tangential velocities with which the web is moved, the conversion into a rotational speed is of course). From the velocities ν ₁ and ν ₂ results in the web 101 between the role 103 and the infeed plant 110 a web tension F ₁₂ . In the illustrated embodiment, the web tension F _{12 is} controlled in the open loop without feedback as a controlled variable by a computing unit 150 as a manipulated variable, the winding speed ν _{1 is} specified or influenced. The relevant for the invention change in the controlled variable "web tension" can here indirectly via a change in the actual drive torque of the drive of the role 103 be determined. The actual drive torque can be determined, for example, via the current consumption, as is known in the prior art.

A further improved embodiment is in 2 shown in which the winding device 200 via a return of the web tension F ₁₂ has, so that a closed-loop control is realized. To measure the web tension F ₁₂ is a so-called load cell 210 provided, as is known in the art.

One of the 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. Another comparable embodiment involves the control of a tangential velocity ν _{1 of} the roll 103 (or the associated speed).

A further improved embodiment is in 3 shown in which the winding device 300 has a dancer position control. This is a so-called dancer 310 provided in which a dancer roll 311 is movable in one direction x. The actual dancer position x _is to the arithmetic unit 150 By influencing the speed ν _1, the actual dancer position x _{is set} to a desired dancer position x _soll .

The illustrated embodiment also has a draft control, which in this case, however, is not relevant to the invention. The of the load cell 210 measured tensile force F ₁₂ is sent to a computing unit 160 transmitted, which sets according to a control deviation, for example, the dancer pressure P of a pneumatic cylinder.

As long as the described regulations are active, the diameter of the winding can 102 on the roll 102 be calculated by comparing the velocities ν ₁ and ν ₂ , since the diameter of the driven roller of the feed train 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 machine control is changed depending on the current winding diameter, usually by a so-called. Fine balance (corresponds to a transmission 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 winding speed ν ₁ 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.

In the context of the invention, which is explained below with reference to a preferred embodiment, the output diameter can now be calculated on the basis of already known sizes.

In 4 are just the elements relevant to the following considerations 3 shown. L ₁₂ describes the length between the roll 103 in the infeed plant 110 , D ₁ the output diameter of the winding 102 , D ₂ the diameter of the driven cylinder of the intake 110 , D _{T is} the diameter of the dancer roll and x _is the actual dancer position.

In the present embodiment, the total length l _ges the web 101 between the role 103 and the infeed plant 110 to determine which of the dancer position x _is dependent (the deeper the dancer roll 311 in 4 is, the longer the web is). An optionally non-rectangular geometry will be taken into account by the person skilled in the art in the calculation of the total length l _ges .

From the comparison of the two speeds ν ₁ and ν ₂ may with knowledge of the diameter D _2, with knowledge of the actual dancer position _x (which here is the controlled variable) and consideration of the geometric relationships of the diameter D of the winding ₁ 102 calculated according to: l _ges = L ₁₂ + 2 x _is + 0.5 · π · D _T - D _T (1) L [m], x [m], D [m]

Δφ [rad], D [m], x [m]
aus (1) und (2) folgt:

When viewing during a period of time T, there is a change Δx _is the actual dancer position and it results from the velocities ν ₁ and ν ₂ respectively rotations of the rollers by an angle Δφ ₁ or Δφ ₂ and from this:

Δφ [rad], D [m], x [m]
from (1) and (2) follows:

Thus, the output diameter D _{1 of} the winding 102 Ax from the change of the actual dancer position (= controlled variable) during the time period T _is under consideration of winding speed ν ₁ and web transport speed ν ₂ are calculated during this period.

At standstill of the web with ν ₂ = 0 or Δφ ₂ = 0 results in the following simplification:

In this case, the diameter can be changed by turning the roller 103 and observing the effect on the controlled variable. Alternatively, it is also possible to change the setpoint value for the controlled variable (here dancer position) at standstill and to determine the change in Δφ ₁ after the compensating process of the controller has taken place.

An analogous simplification for ν ₁ = 0 or Δφ ₁ = 0 and ν ₂ > 0 or Δφ ₂ > 0 (Role 103 at a standstill and infeed 110 in motion) can also be derived and used.

The following explains how the output diameter D _{1 of} the winding 102 in an embodiment according to the 1 and 2 is determined.

From Hooke's law a change ΔF of the web tensile force results from a change Δε of the web elongation: ΔF = E · A · Δ∈ (5) F [N], modulus E [N / m ² ], cross-sectional area A [m ² ], e [%]

E-modulus and cross-sectional area can be determined and assumed to be constant.

F [rad], r [m], l [m], x [m]For the change Δε of the web elongation applies:

F [rad], r [m], l [m], x [m]

With (5) and (6):

Thus, the output diameter D _{1 of} the winding 102 from the change .DELTA.F of the tensile force (= controlled variable) during the period T, taking into account the winding speed v ₁ and the web transport speed v ₂ during this time period.

At standstill of the web with ν ₂ = 0 or Δφ ₂ = 0, the following simplification results:

In this case, the diameter can be changed by turning the roller 103 and observing the effect on the controlled variable. Alternatively, it is also possible to change the setpoint value for the controlled variable (in this case, for example, tensile force, drive torque or speed) at standstill and to determine the change in Δφ ₁ after the compensating process has taken place.

An analogous simplification for ν ₁ = 0 or Δφ ₁ = 0 and ν ₂ > 0 or Δφ ₂ > 0 (Role 103 at a standstill and infeed 110 in motion) can also be derived and used.

In a sensorless winding device, eg. According to 1 , ΔF can indirectly from the change ΔM _{1 of} the actual drive torque of the role 103 during the time period T are derived according to:

undIt then follows:

and

It is expedient to choose the angle 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 angle change, the more accurate the calculation result becomes. because then then errors (eg, measurement errors, noise) lower impact. One way to solve this problem is to determine the exit diameter with only a small angle change. 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.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 2050699 A2 [0003]

Claims (13)

Method for calculating the initial diameter (D ₁ ) of a web winding ( 102 ) on a roll ( 103 ) after a roll change, wherein the web ( 101 ) of the role ( 103 ) and a transport device ( 110 ) of the processing machine with a web transport speed (ν ₂ ) or a transport device ( 110 ) of the processing machine with a web transport speed (v ₂ ) and taken on the roll ( 103 ), the roll ( 103 ) is rotated at a variable winding speed (ν ₁ ), which _is given as a manipulated variable in the context of a control of a controlled variable (x, F ₁₂ ), wherein the output diameter (D ₁ ) of the web winding ( 102 ) on the roll ( 103 ) after the roll change is calculated from a change in the controlled variable (x _ist , F ₁₂ ) during a predetermined time span taking into account the winding speed (v ₁ ) and the web transport speed (v ₂ ) during this period. The method of claim 1, wherein the controlled variable _(x) is a dancer position (a drive torque of a drive of the roller 103 ), a tangential velocity or a rotation speed of the winding ( 102 ) or a tensile force (F ₁₂ ) in the web ( 101 ) between role ( 103 ) and transport device ( 110 ). Method according to claim 1 or 2, wherein an angular change of the roll ( 103 ) and / or an angular change of the transport device ( 110 ) are taken into account in the calculation of the initial diameter (D ₁ ). Method according to claim 3, wherein the setpoint value for the controlled variable is changed and the output diameter (D ₁ ) is calculated from the resulting change in the controlled variable (x _ist , F ₁₂ ) during the predetermined time period taking into account the angular change of the roll ( 103 ) and / or the transport device ( 110 ) during the predetermined period of time. A method according to claim 3 or 4, wherein a first angular change is performed, which consists of a maximum allowable change in length of the web ( 101 ) between role ( 103 ) and transport device ( 110 ) and a maximum possible exit diameter. A method according to claim 5, wherein a first output diameter is calculated taking into account the first angular change, a second angle change is carried out, which results from the maximum permissible change in length of the material web ( 101 ) between role ( 103 ) and transport device ( 110 ) and the first output diameter and a second output diameter is calculated taking into account the second angular change. Method according to one of the preceding claims, wherein the length of the web ( 101 ) between role ( 103 ) and transport device ( 110 ) is taken into account in the calculation of the output diameter (D ₁ ). Method according to one of the preceding claims, wherein a modulus of elasticity and a cross-sectional area of the web ( 101 ) between role ( 103 ) and transport device ( 110 ) are taken into account in the calculation of the initial diameter (D ₁ ). Method according to one of the preceding claims, wherein the roll change is performed at standstill of the processing machine. Method according to one of the preceding claims, wherein during the predetermined time period, the winding speed (ν ₁ ) is zero and the web transport speed (ν ₂ ) is greater than zero. Method according to one of claims 1 to 9, wherein during the predetermined period of time, the winding speed (ν ₁ ) is greater than zero and the web transport speed (ν ₂ ) is zero. Method according to one of the preceding claims, wherein the processing machine is a printing machine, a web-fed printing press, a newspaper printing press, a commercial printing press, a gravure printing machine, a packaging printing press, a digital printing press, a securities printing press, a bag machine, an envelope or a packaging machine. Arithmetic unit which is adapted to carry out a method according to one of the preceding claims.

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