DD278250A3 - ARRANGEMENT FOR ACCELERATING A REPLACEMENT WRAPPING ROLLER - Google Patents

Abstract

The invention relates to an arrangement for accelerating a replacement winding roll in unwinding devices for railway good and is particularly applicable in printing press construction. The replacement winding roll has a drive control, which is connected to a setpoint generator for acceleration, a measured value of the peripheral speed differentiator and a computing and storage unit, the transmitters for the peripheral speed, speed and path speed, the setpoint generator and a current transformer are connected in the current path of the actuator of the drive. As a result, the replacement bobbins are accelerated regardless of the moment of inertia with always the same, vorwaehlbarer, kept constant tangential acceleration. Thus, the acceleration time and the moment of inertia can be calculated in good time. Fig. 1

Description

Explanation of the essence of the invention

The invention is based on the object einfi arrangement for accelerating a replacement winding roll in unwinding devices for sheet material with a regulated drive for the spare winding roll, a transducer for the peripheral speed and a computing and storage unit of the transducers for the peripheral speed and speed the replacement winding roll and a transmitter for the web speed is fed, and a control device with a downstream speed controller, which is in communication with the actuator of the drive, which ensures the timely determination of the acceleration time of the replacement winding roll and its mass moment of inertia and the glue tip is gentle.

According to the invention, the object is achieved in that the transmitter, "r feeds the peripheral speed of the spare reel a Difforenzierglied, the output side of the actual value input of a Vergleichsg .. jdes jdes in connection, the setpoint input with a setpoint generator for the tangential acceleration and its output with the Control device is connected, and a current transformer in the current path of the actuator of the drive and the setpoint generator for acceleration to the pitch and storage unit are connected.

As a result, all replacement winding rollers regardless of their size or their mass moment of inertia with always the same, preselectable, held constant tangential acceleration accelerated. This makes it possible to accurately calculate the required acceleration time of the replacement winding roll at any time at the existing web speed of the processing machine according to a very simple mathematical relationship. The thus determined in time acceleration time makes it possible to set the acceleration start of the replacement winding roll optimally, so that prevents the accelerated role to bond unnecessary rotations performs or the role reaches the web speed too late and the old role is used up before the execution of the bond , As a result, adhesive bonds with a waste of paper and machine downtimes are avoided.

The arrangement according to the invention also makes it possible, at the beginning of the acceleration process, to determine the Mas's moment of inertia of the replacement winding roll. Thus, in the case of a stop braking during startup, the braking torque can be metered as a function of the mass-carrier torque. In the case of a small winding roll, the adhesive tip is protected in the peripheral drive and the winding tube is spared in the case of center drive, and the risk of false gluing, machine downtimes, reduced printing speed or roller separation is reduced. From the moment of inertia, the roll mass can also be determined easily and stands, for example. for process data acquisition of the processing machine.

Finally, the acceleration of all replacement winding rolls with the same tangential acceleration has the advantage that even with small bobbins, the adhesive tip is not exposed to increased inertial force and thus the risk of lifting.

embodiment

The invention will be explained in more detail below on some embodiments.

The accompanying drawings show the block diagrams of arrangements for accelerating replacement winding rolls

Fig. 1: an arrangement with belt drive Fig. 2: an arrangement with center drive.

The acceleration assembly shown in Fig. 1 includes a two-armed roller stand 1, which carries the old winding roll 2 and the spare winding roll 3. From the old winding roll 2, the material web 4 is unwound and the processing machine, for example, a printing press supplied. The web drives a web guide roll 5 with a web pulse generator 6, which is connected to a computing and storage unit 7 not. Each arm of the roll stand 1 carries a revolution pulser 8; 9, which emits a pulse per roller revolution. By means of a switching device 10 respectively belonging to the replacement winding roller revolution pulse, in the drawing so the revolution pulse generator 8, connected to the Rechon- and memory unit 7. At the replacement winding roll '- is a drive belt 11, which is in drive connection with a DC motor 12. With the latter, a tachogenerator 13 and a circumferential encoder 14 are further coupled. While the circumferential pulse generator 14 is connected to the arithmetic and memory unit 7, the tachogenerator 13 feeds a differentiating element 15, which is connected on the output side to the actual value input of a comparison element 16. The setpoint input of the comparison element 16 st.aht with the arithmetic and memory unit 7, the output with a control device 17 in connection. The latter is followed by a speed controller 18 whose output is passed to the DC motor 12 as an actuator. In the armature circuit of the DC motor 12 is a current transformer 19, which is connected with the interposition of a current-voltage converter 20 to the computing and storage unit 7. The latter is still connected to the control device 17

 In the further explanations, the symbols used have the following meaning:

a, tangential acceleration

a, o, tangential delay

D Diameter of the spare roll

f function

In the armature current of the acceleration motor

J ₂ mass-inert mol. »Ent of the center drive

Jg Mass moment of inertia of the belt drive

Jk Moment of inertia of roller bearing (cone)

Jh Mass moment of inertia of the spare winding roll

KibifKg constant

M _A f .. Drive torque with belt drive

Μ " Drive torque at center drive M _B , G Braking torque for belt braking Μ _Β , ζ Braking torque for center braking mr Frictional torque of the roller bearing M "g Frictional torque of the belt drive m Mass of replacement winding roll N Circumferential path per perimeter pulse η Speed of the acceleration motor S Pathway per path impulse tv time interval ta acceleration time V ₈ web speed Vu circumferential speed zb Number of path pulses Zd Number of revolution pulses To Number of circumferential pulses ω Angular velocity of the acceleration motor

In the course of a role change process not to be described in more detail, the replacement winding roll 3 is to be adhered to the material web 4 of the old wound roll 2 that is going to end. For this purpose, the replacement winding roller 3 is accelerated by means of the DC motor 12 in its peripheral speed V ₁₁ from zero to the web speed V ₈ . This is done with a constant tangential acceleration a "which is specified in the embodiment of a voltage at the comparator 16. This setpoint is stored in the arithmetic and memory unit 7. It can also be another setpoint generator, such as a potentiometer, are used, which is connected to the arithmetic and memory unit 7 and the comparator 16. The actual value of the tangential acceleration is obtained as a voltage value by differentiating the voltage of the tachogenerator 13 after time in the differentiator 15 and fed to the comparator 16. With the setpoint deviation determined there, a control variable is derived in the control device 17. The thus instructed speed controller 18 causes a corresponding change in the speed of the DC motor 12 brought about.

Due to the linear increase in circumferential speed increase per unit time, which is linear with constant tangential acceleration, the required acceleration time t "of the replacement winding reel 3 results from the relationship

a

 or.

t _a = K ₁ · v _B (2)

K, = - (3)

a _t

as a constant.

The web speed V ₈ is calculated in the arithmetic and storage unit 7 from the number of path pulses Z _{8 of} the track pulse generator 6 over a predetermined time interval T _v and the path S per track pulse according to the equation

(4)

determined.

For the drive torque Mag of the acceleration motor for belt drive applies

with K ₀ = HL ₌ 2Tt- η _

^{2 v} u ^v u

From equation (6) results in the moment of inertia Jr of the set winding roll 3 to

M ₁

RG

D ² -K ₂ D ₆ -D ²

M ₁ .

^D (7)

4 a,

4 a.

t ^r "t '~" t

In this case, the drive torque Mag is a known function of the armature current I _{M of} the DC motor 12,

The value of the armature current I _M is supplied by the current transformer 19 and converted by means of the current-Spbnnungs converter 20 into a voltage of the arithmetic and memory unit 7 is supplied

 With equation (8) and the constants

K ₂

4 K ₂ mrg 4 kl JG

(9) (10) (11)

mr

Equation (7) can be transformed

f (i _M )

D ² -

(12) (13)

(14)

The constants are specific to the roll-off, as well as the function of the armature current is fixed, and the tangential acceleration a, is given. The initial diameter D of the spare reel 3 at its first rotation is calculated from the number of circumferential pulses of the circumferential encoder 14 between 2 pulses Z _{D of} the rotary encoder 8 and the circumferential path N per circumferential pulse according to the equation

(15)

determined in the arithmetic and memory unit 7. Thus, the mass moment of inertia Jr can now be calculated by means of the latter.

At the same time, the mass m of the replacement winding roll is calculated too

8J ₅ D ²

(16)

and can be utilized, for example, for process data of the processing machine.

With the presence of the mass moment of inertia Jr, the braking torque M ₈ , _G for belt braking of the replacement winding roller is calculated to be analogous to the components acting during acceleration

RG

tBr

^K

tBr

D - K ₂ (17),

wherein the tangential delay a, _B , is specified. In the case of a stop braking, the braking torque Mb ₍ q) calculated by the computing and storage unit 7 is supplied to the control device 17. The latter then aborts the acceleration control of the replacement winding reel 3 and controls the speed controller 18 in such a way that it operates in four-quadrant operation operating DC motor 12 generates the braking torque.

In the exemplary embodiment, the acceleration of the replacement winding roll takes place by means of a motor. The invention can also be applied, for example, when the drive of the replacement winding roll from the main drive of the processing machine z. B. via an electric clutch as an actuator. It is then the corresponding dependence of the transmitted torque of the clutch from the excitation current and the proportion of the clutch on the moment of inertia Jg changed constant K ₅ entered into the computing and storage unit.

In Fig. 2, an accelerator assembly is shown, which includes a two-armed roller stand 21. The latter carries the old winding roll 22 and the replacement winding roll 23. From the old winding roll 22, the web 24 is unwound and u. a. guided over the web guide roller 25, which carries a connected to a computing and storage unit 26 track pulse generator 27. At the Wickelrollenspinde! 28 of the replacement winding roller 23 engages a DC motor 29, to the winding roller spindle 30 of the old winding roller 22, a DC motor 31 at. Each arm of the roller stand 21 carries a revolution pulser 32; 33, which emits a pulse per roller revolution. By means of Umschalieinrichtungen 34; Each of the equivalent to the spare winding roll DC motor and revolution pulse are effective. In this case, in FIG. 2, the revolution pulse generator 32 is connected to the computing and storage unit 26 and the DC motor 29 to the output of a speed controller 36. On the shell of the replacement winding roll 23 is located on a roll 37, with a connected to the computing and storage unit 26 peripheral encoder 38 and a tachometer generator 39 are gek gekippelt. The latter feeds a differentiating element 40. Its output is fed to the actual value input of a comparison element 41, whose setpoint input is connected to the arithmetic and memory unit 26 and whose output is connected to a control device 42. The output of the latter is guided on the speed controller 36. In the armature current path for the DC motors 29; 31 is a current transformer 43, which is connected with the interposition of a current-voltage converter 44 to the computing and storage unit 26. With the latter is still the controller 42 in conjunction.

In the course of the role change operation, the replacement winding roll 23 is to be adhered to the material web 24 of the ending old winding roll 22. For this purpose, the replacement winding roller 23 is accelerated by means of the DC motor 29 in its peripheral speed v _y from zero to the web speed v _B. This is done with a constant tangential acceleration a, which is specified in the embodiment of a voltage at the comparison element 41. The setpoint generator is the arithmetic and memory unit 26, in which the desired value of the tangential acceleration a, is stored. The actual value of the tangential acceleration is obtained as the voltage value by differentiating the voltage of the tachogenerator 39 with respect to time in the differentiating element 40 and supplied to the comparison element 41. With the setpoint deviation determined there, a control variable is derived in the control device 42. The thus instructed speed controller 36 performs a corresponding Ä ^r . «Jbrurig the speed of the DC motor 29 brought about.

For the determination of the acceleration time t _{a of} the replacement winding roll 23, the equation 2 applies analogously to the first embodiment

ta = K, V ₈ (2)

K ₁ = - (3)

as a constant.

Similarly, the web velocity v _B according to equation (4)

from the number of path pulses Z _{B of} the web pulse generator 27 over a predetermined time interval T _v and the path S determined per path pulse.

For the drive torque Maz of the acceleration motor with center drive applies

2 ü · a 2 3 + 3 · a

μ = ^{R t} + ^{z K t} + μ (18)

"AZ D ⁺ D ^{+ n} R.

From equation (19), the mass moment of inertia .i J _{R of} the replacement winding roll 23 is increased

M-D M-D

^ R = "Tap - ³ Z- ⁰ K- -2-57. < ¹ 9,

The drive torque Maz is a known function of the armature current Im of the DC motor 29,

The value of the armature current Im is supplied by the current transformer 43 and converted by means of the current-voltage converter 44 into a voltage supplied to the arithmetic and storage unit 26

 With equation (20) and the constants

K ₈ = J ^ - (21)

K ₉ = J _z + J _K (22)

Equation (19) can be transformed

- K

0_ a

(23)

The constants K ₈ and K ₉ are specific to the roll-off, as is the function of the armature current, and the tangential acceleration a, is predetermined. The initial diameter D of the spare winding roll 23, as in the belt-driven accelerator, during the first reel rotation according to equation (16)

To-N

(15)

from the number of circumferential pulses to the circumferential encoder 38 between 2 pulses Zd of the rotary pulse generator 32 and the circumferential path N per circumferential pulse in the Rechenurii storage unit 26 determined. Thus, the mass moment of inertia Jr can now be calculated by the latter according to equation (23). At the same time, the mass m of the replacement winding roll 23 can also be calculated according to equation (16).

8JR D ¹

With the presence of the mass moment of inertia Jr, the braking torque M _BrZ for center braking of the replacement _{winding roller} 23 is calculated analogously to the components acting during acceleration

2 D

BrZ

tBr +

t - M

(24)

wherein the tangential _delay a _tB , is specified. In the case of a stop braking, the calculated by the arithmetic and memory unit 26 braking torque M _{f f} z in the form of a voltage of the control device 42 is supplied. The latter then aborts the acceleration control of the replacement winding roll 23 and controls the speed controller 36 so that the operating in four-quadrant DC motor 29 generates the braking torque.

In the embodiments, the roll stand each carry two arms. The invention is also applicable to three-armed roller stands.

Furthermore, using the invention, the arithmetic and memory unit can also be fed by analog transducers. Also, the transmitter for the speed of ErsaU-winding roll deliver one pulse train per revolution, in which case in formula (15) still receives the ratio of the pulses per revolution and the evaluated pulses as a factor. Likewise, a digital encoder can be used to control the differentiating, if necessary, with the interposition of a digital-to-analog converter. Also, the differentiator and the arithmetic and storage unit can be connected to a common peripheral speed sensor of the spare winding roll.

Claims (2)

Arrangement for accelerating a replacement winding roll in unwinding devices for web-shaped goods with a regulated drive for the spare winding roll, a transducer for the peripheral speed and a computing and storage unit consisting of transducers for the peripheral speed and speed of the spare winding roll and a transmitter for the web speed is fed, and a control device with a downstream speed controller, which is in communication with the actuator of the drive, characterized in that the peripheral speed sensor of the replacement winding roller (3; 23) a differentiator {15; 40) which is connected on the output side to the actual value input of a comparison element (16, 41) whose setpoint input is connected to a setpoint generator for the tangential acceleration and whose output is connected to the control device (17, 42), and a current transformer (19, 43 ) in the current path of the actuator of the drive and the setpoint generator for acceleration to the computing and storage unit (7; 26) are connected. For this 2 pages drawings Field of application of the invention Did invention relates to an arrangement for accelerating a replacement winding roll in unwinding devices for web-like material in web-processing machines, in particular flollen rotary printing presses. Characteristic of the known state of the art ! n unwinding devices with automatic reel change is used to define application points of reel change steps u. a. the time required to accelerate the spare reel from zero to web speed. This time is fixed in a known control arrangement (OE-PS 2619236). For the reasons mentioned below, however, the required acceleration time should be as accurate as possible. If the acceleration time is too large, the replacement winding roller accelerated to the web speed of the printing press will perform additional rotations until this time has elapsed. This et increases the risk that solves the prepared for bonding adhesive tip of the winding roll and a Fahlklebung done or aborted the roll change process and the Anklabung must be performed by hand. If, on the other hand, the acceleration time actually required is greater than the intended one, then the gluing process subsequent to the acceleration is initiated late, which may result in the roller grate of the unwinding old winding reel being used up before the gluing and the automatic gluing failing. All folds result in machine downtime and waste. It is also advantageous to unwinding the knowledge of the moment of inertia of the replacement winding roll. According to EP application 185EI5 this is calculated from the measured time for the acceleration of the replacement winding roll to web speed. It is disadvantageous that the moment of inertia for achieving a controlled braking torque of the replacement winding roller in the case of a stop braking during the acceleration process is not yet available. Thus, in the stop braking of a small winding roll with an unnecessarily large braking torque in arrangements with belt drive the adhesive tip and in arrangements with center drive the sleeve on the cone heavily loaded. In the former case, the displacement of the adhesive tip threatens and as a result a Fehlklebung. The second case may require further pressure with reduced web speed due to damage to the winding tube or even lead to the rejection of this role with concomitant pressure interruption. A further disadvantage is that the acceleration of the replacement winding rolls is done with constant torque. In a small replacement winding roll thereby the adhesive tip is heavily loaded, which can lead to their lifting with the consequences mentioned above. Object of the invention The invention aims to provide an arrangement which avoids false bonds and thus reduces the accumulation of waste and machine downtime.