Apparatus for influencing a running material web

Abstract

An apparatus (1) serves to influence a running material web (2). To this end, the apparatus (1) has at least one adjustable roller (4), which deflects the material web (2). In order to improve the web running characteristics of the material web (2), the at least one roller (4) is adjustable by at least two degrees of freedom. Moreover, the at least one roller (4) is operatively connected to at least two actuators (17) such that at least one of the actuators (17) is assigned to each of the degrees of freedom.

Claims

1. Apparatus for influencing a running material web, wherein said apparatus comprising: at least one sensor, determining position or tension of said material web, at least one adjustable roller, which deflects said material web, wherein said at least one roller is adjustable by at least two degrees of freedom, at least one controller, being operatively connected with said at least one sensor, said at least one controller outputting a first signal representing a pivot angle α, at least two transmitters producing second signals, at least two actuators; at least one computation circuit receiving said first signal representing said pivot angle α and said second signals being proportional to X- and Y-coordinates of an imaginary pivot axis, said at least one roller is operatively connected to said at least two actuators such that at least one of said actuators is assigned to each of said degrees of freedom, wherein at least one of said actuators is a linearly adjustable drive, having a first and a second end, being spaced apart from each other by an actuator length L said first end being pivotably held in a first pivot mounting and said second end being pivotably held in a second pivot mounting connected to said at least one roller said first pivot mounting in its unpivoted position having a relative vectorial distance {right arrow over (A)} from said pivot axis, and said second pivot mounting in its unpivoted position having a relative vectorial distance {right arrow over (B)} from said pivot axis, wherein said at least one actuator is operatively connected to said at least one computation circuit, said at least one computation circuit calculating said actuator length L from said relative, vectorial distances {right arrow over (A)},{right arrow over (B)} from said pivot axis and from said pivot angle α of said at least one roller as follows $\left(\alpha =0°\right)\text{:}L=\sqrt{{\stackrel{.fwdarw.}{A}}^2+{\stackrel{.fwdarw.}{B}}^2+\stackrel{.fwdarw.}{B}\left[{\stackrel{.fwdarw.}{A}}^t\left(\begin{array}{cc}-\cos \left(\alpha \right)& \sin \left(\alpha \right)\\ -\sin \left(\alpha \right)& \cos \left(\alpha \right)\end{array}\right)\right]}$ wherein said at least one computation circuit acts on said at least one of said actuators to set the actuator length L to the calculated actuator length L provided by said computation circuit in order to control the running characteristics of the material web including the web run and/or the web tension.

2. Apparatus according to claim 1, wherein said at least one roller is held in at least one guide.

3. Apparatus according to claim 1, wherein said at least one controller is a material web controller, which is operatively connected to said at least one roller.

4. Apparatus according to claim 3, wherein said material web has a web edge having a position and said at least one sensor is a web edge sensor, which registers said position of said web edge and influences said at least one material web controller.

5. Apparatus according to claim 1, wherein said material web having a width and a tensioning force differential across said width of said material web, wherein said at least sensor comprises at least two force sensors, which register said tensioning force and influence said at least one material web controller.

6. Apparatus according to claim 3, wherein said material web having a width and a tensioning force differential across said width of said material web, wherein said at least one sensor comprises at least two force sensors, which register said tensioning force and influence said at least one material web controller.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF DRAWINGS

(1) Other advantages and characteristics of this invention will be explained in the detailed description below with reference to the associated figures that contain several embodiments of this invention. It should however be understood, that the figure is just used to illustrate the invention and does not limit the scope of protection of the invention.

(2) Wherein:

(3) FIG. 1 shows an apparatus for influencing a running material web in an initial setting of a roller,

(4) FIG. 2 shows the apparatus according to FIG. 1 in the pivoted position of the roller,

(5) FIG. 3 shows an alternative embodiment of the apparatus according to FIG. 1, and

(6) FIG. 4 shows a preferred embodiment of a computation circuit for the driving of actuators.

DETAILED DESCRIPTION OF THE INVENTION

(7) FIG. 1 shows a three-dimensional representation of an apparatus 1 for influencing a material web 2. The material web 2 possesses a running direction 3 and is deflected around at least one roller 4. In the illustrative embodiment according to FIG. 1, the rear one of the two rollers 4 is necessarily provided, whilst the front roller 4, drawn in dashed representation, is merely optional. According to the type of material web and the geometrical infeed and outfeed conditions of the material web 2, a single roller 4 can also suffice, so that the roller 4 shown in dashed representation can also be dispensed with.

(8) The two rollers 4 are rotatably supported at the ends in roller bearings 5. It is here immaterial whether the rollers 4 are freely rotatably or are motor-driven. This choice is essentially dependent on the friction losses of the material web 2 as it is deflected around the roller 4.

(9) Held on the rollers 4 by further roller bearings are rolls 6, which are guided in rolling arrangement on a guide 7. In principle, the rolls 6 can also be supported on the roller bearings 5, which leads, in particular, to reduced load upon the bearings. Moreover, instead of the rolls 6, slide shoes can also be attached directly to the roller bearings 5, which slide shoes slide along the guide 7. If the material web 2, in accordance with the representation in FIG. 1, is fed from below to the apparatus 1 and is led away downwards from this, then the tensile force of the material web 2 exerts solely a downwardly directed force component on the rollers 4. In this case, it is wholly sufficient to provide an appropriate guide 7 only beneath the rollers 6 or the alternative slide shoes. In particular, if alternative web courses are also intended to be allowed, it is necessary, where appropriate, to make the guide 7 double-sided, so that the rolls 6 reach into an appropriate free space of the guide 7 provided on the top side and bottom side of the rolls 6.

(10) Although the material web 2 moves basically in the direction of the running direction 3, owing to external influences or inaccuracies in the alignments of rollers in upstream processing equipment, a slight transverse course 8 of the material web 2 is also obtained. In the absence of further measures, the material web 2 would be displaced beyond the roller ends, which would make further processing of the material web 2 impossible. For this purpose, the rollers 4 of the apparatus 1 are made adjustable. The adjustment of the rollers 4 is here realized such that a web edge 9 is held in a preset desired position. For this purpose, the apparatus 1 has a web edge sensor 10, which registers the position of the web edge 9 permanently or cylindrically and feeds it via a signal path 11 to an actual value input 12 of a material web controller 13. The material web controller 13 preferably has a P, PI or PID behaviour. The material web controller 13 additionally possesses a desired value input 14, which is operatively connected to a desired value transmitter 15.

(11) In order to form a closed control loop, the material web controller 13 must be operatively connected to the rollers 4 such that the output signal of the material web controller 13 provokes an adjustment of the roller 4. It is known to connect the material web controller directly to an actuator which pivots the roller 4. In this case, however, the roller 4 would have to have a fixed pivot axis, thereby considerably restricting the applicability of the apparatus 1.

(12) In order to enable not only the roller 4 to be pivotable, but also a pivot axis 16 to be variably adjustable, the roller 4 is adjustable by three degrees of freedom—two translatory and one pivotal degree of freedom. The roller is acted on by three actuators 17, which are configured, for example, in the form of hydraulic cylinders, pneumatic cylinders or electric servo drives. These actuators 17 respectively have a first pivot mounting 18 and a second pivot mounting 19. The first pivot mounting 18 is here configured fixed to a machine frame (not represented) and is therefore, in terms of its position, independent of the setting of the actuator 17. By contrast, the second pivot mounting 19 is connected to the roller bearings 5 of the roller 4 and is thus dependent, in terms of its position, on the actuator setting. By adjustment of the actuators 17, the distance of the first pivot mounting 18 from the second pivot mounting 19 changes, whereby the roller bearing 5 adjusts itself in accordance with the roller 4.

(13) On each actuator 17 there is additionally provided a displacement transducer 20, which registers the respective setting of the actuator 17 and delivers this via a signal path 21.

(14) To each actuator 17 is assigned a computation circuit 22. This computation circuit 22 is operatively connected via a signal path 23 to an X-value transmitter 24, which adjustably sets the X-coordinate of the pivot axis 16. Via a further signal path 25, the computation circuit 22 is operatively connected to a Y-value transmitter 26, which sets the Y-coordinate of the pivot axis 16. Via a further signal path 27, the computation circuit 22 receives the output signal of the material web controller 13. The signal paths 23, 25 and 27 are identical for all computation circuits 22, so that these are mutually connected in accordance with a parallel circuit. By contrast, the signal path 21 transmits the momentary position of the respective actuator 17 and is individual to each of the computation circuits 22. The computation circuits 22 respectively possess an output 28, which is connected to respectively one of the actuators 17 via, in each case, a signal path 29. The driving of the individual actuators 17 is thus calculated independently from one another in accordance with the presets of the material web controller 13 and of the X-value transmitter 24, as well as of the Y-value transmitter 26.

(15) FIG. 2 shows the apparatus 1 according to FIG. 1 in the adjusted position of the rollers 4. The pivot axis 16 has here been used as a virtual axis, which is defined in terms of its position by no mechanics whatsoever. The pivoting of the roller 4 about the pivot axis 16 is realized only by appropriately coordinated driving of the actuators 17.

(16) It is pointed out that the application of the apparatus 1 for regulating the web edge 9 of the material web 2 should be construed as merely illustrative. In principle, the apparatus 1 can influence the material web 2 in any chosen manner, insofar as this is possible by adjustment of at least one of the rollers 4. FIG. 3 shows an alternative embodiment of the apparatus 1 according to FIG. 1, wherein the same reference symbols denote the same parts. Instead of the web edge sensor 10, force sensors 30, which measure the bearing force of the roller 4, are provided in the roller bearings 5. Both force sensors 30 are operatively connected to a differential amplifier 31, which calculates the differential of the bearing forces at both roller ends and feeds this to the actual value input 12 of the material web controller 13. In this case, the apparatus 1 operates as a tension equalizing device in order to equalize tensions of the material web 2 which are formed transversely to its running direction 3. The web run of the material web 2 is chosen such that it has a greatest possible change in length upon adjustment of the roller 4. This is achieved by the material web departing from the horizontal direction, being deflected through 180° and being led off again in the horizontal direction. One roller 4 is here sufficient to regulate the tensioning force.

(17) The computation circuits 22 are constructed identically to one another and are described by way of example with reference to the basic circuit diagram according to FIG. 4. The same reference symbols here denote the sane parts. The computation circuit 22 receives via the signal path 23 a signal proportional to the X-coordinate of the imaginary pivot axis 16. Via the signal path 25, it receives a signal proportional to the Y-coordinate of the pivot axis 16. The output signal of the material web controller 13 represents the necessary pivot angle of the rollers 4 and is fed to the computation circuit 22 via the signal path 27. Finally, the computation circuit 22 receives the signal of the displacement transducer 20 via the signal path 29. The computation circuit 22 calculates an output signal, which is fed via the signal path 21 to the actuators 17.

(18) The computation circuit 22 has four value transmitters 40-43, the output signals of which represent the X- and Y-coordinates of the rest positions of the pivot mountings 18, 19. The value transmitter 40 here delivers the X-coordinate and the value transmitter 41 the Y-coordinate of the first pivot mounting 18, which is fixedly provided in the frame of the apparatus 1. By contrast, the value transmitter 42 delivers the X-coordinate and the value transmitter 43 the Y-coordinate of the rest position of the second pivot mounting 19, which is connected to the roller bearing 5 of the roller 4. As the rest position should here be understood that non-pivoted position of the roller 4 which is assumed by the at least one roller 4 when the signal at the signal path 27 is equal to zero. The roller 4 will assume this position only when no correction of the web run of the material web 2 is necessary.

(19) Each of the value transmitters 40-43 is operatively connected to a non-inverting input of a differential amplifier 44-47. Inverting inputs of the differential amplifiers 44, 45 are operatively connected via the signal path 23 to the X-value transmitter 24 for determination of the X-coordinate of the pivot axis 16. By contrast, inverting inputs of the differential amplifiers 46, 47 are operatively connected via the signal path 25 to the Y-value transmitter 26 for determination of the Y-coordinate of the pivot axis 16. The differential amplifier 44 thus calculates the X-coordinate of the distance vector of the first pivot mounting 18 from the pivot axis 16. By contrast, the differential amplifier 45 determines the X-coordinate of the distance vector of the second pivot mounting 19 in the rest position of the roller 4 from the pivot axis 16. The differential amplifiers 46, 47 calculate the corresponding Y-coordinates of the two said vectors. An angle signal, which is fed from the material web controller 13 via the signal path 27 to the computation circuit 22, is fed, on the one hand, to a cosine generator 48 and, on the other hand, to a sine generator 49, which calculate from the signal arriving via the signal path 27 the cosine value and the sine value respectively.

(20) The differential amplifiers 44, 46, which represent the X- and Y-coordinate of the first pivot mounting 18, are operatively connected, together with the output signals of the cosine generator 48 and sine generator 49, to multipliers 51-54. These multipliers 51-54 are here wired up such that any combination of output signals of the differential amplifiers 44, 46, on the one hand, and cosine generators 48 and sine generators 49, on the other hand, is multiplied. These multipliers 51-54 are operatively connected on the output side to two summing units 55, 56, the summing unit 55 being inverting and the summing unit 56 being non-inverting. These summing units 55, 56 determine the X-coordinate and the Y-coordinate of the product of the distance vector of the first pivot mounting 18 from the pivot axis 16 with a modified rotation matrix in the form:

(21) $\hspace{1em}\left(\begin{array}{cc}-\cos \left(\alpha \right)& \sin \left(\alpha \right)\\ -\sin \left(\alpha \right)& \cos \left(\alpha \right)\end{array}\right)$

(22) The said distance vector should here be regarded as a line vector and not as a column vector.

(23) In a following step 60, multipliers 61-64 determine squares of the output signals of the differential amplifiers 44-47. Further multipliers 65, 66 determine a scalar product between the distance vector of the second pivot mounting 19 from the pivot axis 16 and the vector which is represented by output signals of the summing units 55, 56.

(24) The output signals of all multipliers 61, 66 are next added in a summing unit 67 and fed to an operational amplifier 68. This operational amplifier 68 is linked back via a squarer 69, so that it calculates the square root of the output signal of the summing unit 67 and delivers it to a signal path 70. The signal at the signal path 70 here represents the required length of the associated actuator 17, i.e. the required distance of its first pivot mounting 18 from the second pivot mounting 19.

(25) An output signal of the operational amplifier 68 is fed to a non-inverting input of a differential amplifier 80, the inverting input of which is connected via the signal path 29 to the displacement transducer 20 of the actuator 17. The differential amplifier 80 calculates an actual-desired value comparison and is operatively connected on the output side to a servo controller 81. This servo controller 81 preferably has a P, PI or PID behaviour and ensures that the position of the actuator 17 is regulated, so that this, regardless of generated forces, assumes a length as is preset as a signal on the signal path 70.

(26) The described computation circuit 22 is relatively complex and is generally realized as a program of a microcontroller, thereby considerably reducing the wiring complexity. The description of this computation circuit as an analogue circuit makes understanding easier, however, since it can be effected, in particular, independently of program language. Each of the three computation circuits 22 is of basically identical construction, the signal paths 23, 25 and 27 of all computation circuits 22 additionally being connected to one another and having the same signals. The individual computation circuits 22 differ only by dint of the signal path 29 individually led up from the associated displacement transducer 20 and by dint of the adjustments of the value transmitters 40-43. On the output side, each computation circuit 22 is individually connected to a selected actuator 17.

(27) As a result of these computation circuits 22, it is possible to drive each actuator 17 individually in such a way that the roller 4 assumes a pivot angle preset by the material web controller 13, the position of the pivot axis 16 being optionally presettable by the X-value transmitters 24 and Y-value transmitters 26. The position of the pivot axis 16 can here be changed even during current control operation.

(28) Since some of the embodiments of this invention are not shown or described, it should be understood that a great number of changes and modifications of these embodiments is conceivable without departing from the rationale and scope of protection of the invention as defined by the claims.

REFERENCE SYMBOL LIST

(29) TABLE-US-00001 1 apparatus 2 material web 3 running direction 4 roller 5 roller bearing 6 roll 7 guide 8 transverse course 9 web edge 10 web edge sensor 11 signal path 12 actual value input 13 material web controller 14 desired value input 15 desired value transmitter 16 pivot axis 17 actuator 18 first pivot mounting 19 second pivot mounting 20 displacement transducer 21 signal path 22 computation circuit 23 signal path 24 X-value transmitter 25 signal path 26 Y-value transmitter 27 signal path 28 output 29 signal path 30 force sensor 31 differential amplifier 40-43 value transmitters 44-47 differential amplifiers 48 cosine generator 49 sine generator 51-54 multipliers 55-56 summing unit 60 step 61-66 multipliers 67 summing unit 68 operational amplifier 69 squarer 70 signal path 80 differential amplifier 81 servo controller