EP0311805B1 - Device for the controlled conveyance of a web to a printing machine - Google Patents

Description

The invention relates to a device for the controlled feeding of strip material to printing machines according to the preamble of claim 1.

From DE-PS 23 05 249 a device is known in which the web tension of a paper web is kept constant by means of a tensioning roller designed as a dancer roller. In order to return the dancer roller into a predetermined starting position after a deflection (paper web tension change) caused by a fault, a pull roller with a shaft gear arranged upstream of the dancer roller is provided. In addition to the main drive of the printing press, the shaft gear is driven by a second reversible control motor, which is connected to the dancer roller via a control circuit. The speeds of the main drive and the control motor are additively superimposed by means of the shaft gear. The control device used receives from a strain gauge measuring element a voltage signal proportional to the deflection of the tensioning roller and combines this multiplicatively with a signal proportional to the tension roller speed (proportional gain), here the speed-dependent proportional portion of the controller is placed in the measuring element.

In the device shown in DE-PS 23 05 249, it is disadvantageous to use a precisely speed-controlled motor which is fed separately from the main drive of the printing press and which is connected directly upstream of the addition gear. On the one hand, this motor and its speed controller must have a performance level due to their function, which represent a considerable cost in terms of acquisition and operation. On the other hand, a motor in the size required for this purpose has the disadvantage that its rotating parts are also of large mass, which are difficult to reverse due to their physical inertia.

DE-A1 25 49 762 shows a drive for a pair of pull rollers. The machine is driven by a gearbox, the transmission ratio of which can be changed by means of an electric drive. The change and thus the setting of the gear ratio occurs depending on the position of a pendulum roller.

Another disadvantage can be seen in the use of the controller, to which a signal proportional to the pulling roll speed is assigned, but which does not correspond to the deflection speed of the tensioning roll to be controlled. The decisive disadvantage of this device is, however, that in the event of failure of the engine, its speed controller or the controller, the pull roller can only be operated at a speed proportional to the printing unit speed, i. H. the infeed unit only runs with a single defined web stretch, which, depending on the type of paper, may exceed or fall below the necessary input tension of the printing machine (for thin papers) (for thick papers).

The invention has for its object an improved device for the return of a deflectable, wrapped by a paper web tension roller in a to create a preselectable starting point.

The object is achieved by the characterizing part of claim 1.

The advantages of the invention are that the feed device can be adjusted manually to different paper web tensions which are required for different types of paper even if the control motor or the controller fails.

In particular, the control device is driven by the main drive of the printing press, so that expensive additional units can be dispensed with. This measure not only reduces the manufacturing costs, but also reduces the susceptibility to failure of the entire device. In addition, the control device ensures a robust, stable system, i. H. a statically and dynamically uniform web tension. The particular advantage of the device is that if the controller or servomotor fails, the device can be operated with a manually selectable constant extension (lag) to the printing unit. In this case, the compensation of the dynamic disturbances by the dancer roller is omitted, but in the long run a web tension can still be selected manually for the different papers, so in general an emergency production is possible.

Fig. 1

Eine schematischen Darstellung eines Einzugwerks mit der erfindungsgemäßen Vorrichtung,

Fig. 2

ein Blockschaltbild von Regelstrecke und Regler mit Übergangsfunktionen der verwendeten Regelkreisglieder,

Fig. 3

eine Seitenansicht der Verstellmechanik.

An embodiment is shown in the drawings and is described below. Show it:

Fig. 1

A schematic representation of a feed mechanism with the device according to the invention,

Fig. 2

a block diagram of the controlled system and controller with transition functions of the control loop elements used,

Fig. 3

a side view of the adjustment mechanism.

A feed mechanism 1 of a printing press has a device for the controlled feeding of strip material 7 (eg paper web) between two cooperating pick-up rollers 2, 3 and a paper roll 4 of a roll changer 6. The device 6 has u. a. a pull roller 8, which cooperates with a pressure roller 9.

The pressure roller 9 is rotatably mounted in the center on two levers 12 which are pivoted with a first end 11 and are laterally symmetrical on side frames 10 of the feed mechanism 1. A second end 13 of the levers 12 is each articulated to a piston 14 of an impression roller (pressure device) 17. The impression rollers 17 consisting of cylinders 16 and pistons 14 are fastened to the side frames 10 of the feed mechanism 1.

The pull roller 8 is rotatably mounted in side frames 10 of the feed mechanism 1 and projects through the side frame 10 with a shaft journal 19 on the drive side. On the shaft journal 19 sits a gear 21, which with a gear 22 arranged vertically below is in meshing engagement. The gear 22 is firmly connected to an output part 23 of an addition gear 24 (e.g. harmonic drive, differential gear, planetary gear). A drive part 26 of the addition gear 24 has a gear 27 which meshes with a gear 28 that can be engaged or disengaged. The coupling for the gear 28 serves to separate the feed mechanism drive from the main drive of the printing press (for example, for cleaning the cylinders) and, since it is not part of the inventive concept, is not further described. The gear wheel 28 meshes with a gear wheel 29 of a shaft 31, which is in drive connection via a bevel gear 32 with a longitudinal shaft 33 driven by the main drive of the printing press.

A control part 34 (wave generator) of the addition gear 24 is firmly connected to a gear 36. The gearwheel 36 meshes with a gearwheel 37, which is firmly seated on an output shaft 38 of a continuously variable adjustment disk transmission 39 (PIV transmission). A drive shaft 42 of the adjusting disk gear 39 rotatably carries a gear 43, which is also in mesh with the gear 22 of the driven part 23 of the addition gear 24. Of course, it is also possible to arrange the gear 43 in meshing engagement with the gear 27 of the drive part 26 of the addition gear 24. The adjusting disk gear 39 has an actuating device which can be driven by means of an actuating motor 46.

The servomotor is powered by a power driver 47 Regulator 48 fed. In addition to the servomotor 46, a handwheel 40 is provided for manual adjustment.

Seen in the web transport direction, a first paper web guide roller 51 is provided behind the pulling roller 8, which deflects the horizontal paper web 7 vertically downwards. The paper web 7 wraps around a tensioning roller 52 designed as a dancer roller and is guided vertically upwards. At about the same height next to the paper web guide roller 51, a second paper web guide roller 53 is arranged, which deflects the paper web 17 horizontally to the right in the direction of the take-up rollers 2, 3.

The dancer roller 52 is rotatably mounted on a left end 57 of two horizontally arranged pivot levers 56. A right end 54 of the pivot lever 56 is pivotally mounted on the side frames 10 of the feed mechanism 1 so as to be pivotable by an angle φ. A piston rod 58 is articulated with its first end 59 to the pivot lever 56 in the middle of the pivot lever 56. A second end 60 is fixedly connected to a membrane 61, which is attached with its circumference 62 in a sealing manner to an inner wall 63 of a cylinder 64. A space 66 formed from cylinder 64 and membrane 61 is connected to a pressure vessel 68 via a pressure line 67. The pressure vessel 68 acts on the space 66 with a constant pressure p _O. In order to be able to adjust the pressure p _O to different tensile stresses, the pressure vessel 68 is connected to a pressure source 70 via an adjustable digital valve 69.

To determine the swivel angle φ with the dancer roller 52 connected pivot lever 56, a cover plate 71 is fastened to the pivot levers 56 and can be inserted into the receiving area of an analog light barrier 72. Depending on the degree of coverage, the light barrier 72 generates an electrical voltage signal U φ which is proportional to the swivel angle φ. The voltage signal U φ is fed to the control device 48.

The control device 48 has a number of control systems which are combined in five blocks A, B, C, D, E. Blocks A, B, C are connected in parallel. The block D is connected in series with the two blocks B, C. The outputs of block A, D are multiplicatively linked in block E. An output signal U _E of block E is fed to the power driver 47 of the control motor 46.

The uniformity of the web tension is determined exclusively by the tensioning roller 52 designed as a dancer roller. Here, the control device 48 takes on the task of quickly returning the dancer roller 52 deflected to compensate for a web tension disturbance to a predetermined target position. The target position is defined as the position which the swivel lever (56) assumes when the web tension is undisturbed. In the exemplary embodiment shown (FIG. 1), this is a horizontal position at a swivel angle φ = 0. Of course, the desired position of the swivel lever 56 can also be arranged in any other position (eg vertically). The dancer roller 52 wrapped in the paper web is returned to a desired position by a corresponding change in the speed of the pull roller 8. A fault in the Paper web tension, the z. B. would cause a voltage drop in the reel changer, has to result in a deflection of the dancer roller 52 from the desired position downward to maintain the web tension. So that the dancer roller 52 is returned to the desired position (horizontal position), the speed of the pull roller 8 must be reduced. The regulating device 48 first determines the setting direction for the stepless adjusting disk gear 39 from the dancer position and generates an output voltage U _E from a voltage U _φ proportional to the dancer roller position.

The voltage U _φ is also rated with a large factor K₁ (z. B. = 1) when the dancer roller 52 shows the tendency to move away from the target position and with a small factor K₂ (z. B. = 0 , 2) rated if the dancer shows a tendency to move towards the desired position. This different evaluation means that the dancer roller 52 strives for its target position asymptotically stable with the same disturbance.

Block A contains three control loop elements 76, 77, 78. The control loop elements 76, 77 are connected in parallel to one another and positively linked to one another by means of an addition point 79. The control loop element 78 is a P system and is connected in series with the control loop elements 76, 77 after the addition point 79. The control circuit element 76 is a PT 1 system and has the function of filtering out an adjustable frequency spectrum, ie to evaluate low-frequency components of long-term disturbances more strongly in the longer term. The control loop element 77 is a P system with an amplifier function. Block A thus generates a low-frequency voltage signal U _{A which is} proportional to the deviation of the dancer position from a predetermined desired position.

The block B contains four control circuit elements 81 to 84. The control circuit element 81 is a PT 1 system for suppressing high-frequency interference, which, after an addition point 86, is followed by the control circuit element 82 designed as a P system with the control circuit element 83 designed as an I system in a negative feedback loop . The control loop elements 82, 83 are used to determine the derivative, which is required to recognize the speed of the dancer roller 52. The control loop element 84 is arranged behind the control loop element 82 and has the function of a non-linear two-point controller which evaluates an output signal of the control loop element 82 with a positive or negative factor depending on the direction of movement of the dancer roller 52. The evaluation with a positive factor takes place with a direction of movement of the dancer roller 52 upwards with a negative factor with a direction of movement downward, the direction of movement being seen absolutely, regardless of the desired position.

The block C contains two series-connected control circuit elements 88, 89. The control circuit element 88 is a PT 1 system for suppressing high-frequency interference. The control circuit element 89 is a non-linear two-point controller for sign recognition, ie for determining the actual position of the dancer roller 52 and a consequent evaluation of the voltage signal U _φ with a positive (e.g. +1) or negative (e.g. -1) Factor. The evaluation with a positive factor takes place e.g. B. when the dancer roller 52 is deflected upward, with a negative factor when the dancer roller 52 is deflected downward.

The block D contains a detection logic consisting of the elements 93, 94, 96, which links the output signals U _B and U _{C of} the blocks C, D together. The link 93 is a decision gate (and gate) with "and" characteristics, ie if both input signals U _B and U _{C are} positive, the linked output signal U₉₃ is positive. Is one or both input signals U _B , U _C negative, the linked output signal U₉₃ is negative. The link 94 is a decision gate with the following "negative and" characteristic: If one or both input signals U _B , U _{C are} positive, the output signal U ist is negative. Are both input signals U _B ; U _C negative, the output signal U₉₄ is positive. The element 96 is a decision gate (or gate) with "or" characteristic, ie if one of the two output signals U₉₃; U₉₄, which are at the same time the input signals for the element 96, are positive, the linked output signal U₉₆ is also positive. Are both signals U₉₃, U₉₄ negative, the output signal U₉₆ is negative.

The output signal U₉₆ is the input signal for a control circuit element 98. The control circuit element 98 regulates the return speed of the dancer roller 52. It consists of a non-linear two-point controller and evaluates the input signal U₉₆ with a factor K₁ (z. B. = 1) when the dancer roller 52 moves from their target position and with a factor K₂ (z. B. = 0.2) when moving the dancer roller 52 in its target position.

The block E forms from the outputs U _{A of} the block A and U _{D of} the block D a multiplicative voltage signal U _E , which is fed to a controlled system 99, consisting of a power driver 47, reversibly drivable motor 46, dancer roller 52 and light barrier 72. In its mode of operation, this controlled system 99 represents a double integrator system.

Parts list

1

Infeed

2nd

Take-up roller

3rd

Take-up roller

4th

Paper roll

5

-

6

Reel changer

7

Tape material, paper web

8th

Pull roller

9

Pressure roller

10th

Side frame

11

End (12)

12

lever

13

End (12)

14

piston

15

-

16

cylinder

17th

Impressionist

18th

-

19th

Shaft journal

20th

-

21

Gear (19)

22

Gear (23)

23

Stripping section (24)

24th

Addition gear (differential gear)

25th

-

26

Drive part (24)

27th

Gear (24)

28

gear

29

Gear (31)

30th

-

31

wave

32

Bevel gear

33

Longitudinal shaft

34

Control unit (24)

35

-

36

Gear (24)

37

Gear (38)

38

Output shaft (39)

39

Variable speed gear

40

Handwheel

41

-

42

Drive shaft (39)

43

Gear (42)

44

-

45

-

46

Servomotor

47

Performance drivers

48

Regulator

49

-

50

-

51

Paper web guide roller

52

Tension roller, dancer roller

53

Paper web guide roller

54

End (56)

55

-

56

Swivel lever

57

End (56)

58

Piston rod

59

End (58)

60

End (58)

61

membrane

62

Scope (61)

63

Interior wall

64

cylinder

65

-

66

room

67

Pressure line

68

pressure vessel

69

Digital valve

70

Pressure source

71

Cover plate

72

Analog light barrier

73

-

74

-

75

-

76

Control loop element

77

Control loop element

78

Control loop element

79

Addition point

80

-

81

Control loop element

82

Control loop element

83

Control loop element

84

Control loop element

85

-

86

Addition point

87

Branch point

88

Control loop element

89

Control loop element

90

-

91

-

92

Controlled system

93

Decision gate

94

Decision gate

95

-

96

Decision gate

97

-

98

Control loop element

99

Controlled system

A

block

B

block

C.

block

D

block

E

block

U _φ

Voltage signal

U _A

Voltage signal

U _B

Voltage signal

U _C

Voltage signal

U _D

Voltage signal

U _E

Voltage signal

φ

Swivel angle

U₉₃

Exit / entrance

U₉₄

Exit / entrance

U₉₅

-

U₉₆

Exit / entrance

Claims (4)

1. Device for the regulated infeed of a material web (7) to printing machines, having a motorised material web drive formed by rollers (8, 9) and wrapped around by a material web, having a tensioning roller (52) constructed as a compensating roller disposed downstream of the material web drive, and having a regulating arrangement (48) using actual and nominal value signals (U_φ) in dependence on the material web tension for the compensating drive of the material web drive roller (8) wrapped around by a material web, and having a differential gear (24) disposed upstream of the material web drive roller (8) and having at least one drive, output and control component (26, 23, 34), characterised in that a drive (22, 21, 19) of the draw roller (8) is connected non-positively to a drive component (43, 42) of a servo gear (39), in that an output component (38) of the servo gear (39) is non-positively connected to the control component (34) of the differential gear (24), in that the servo gear (39) is provided with an apparatus for adjusting its transmission ratio (46), in that the apparatus for adjusting its transmission ratio (46) is connected by way of a regulating apparatus (48) to an apparatus for establishing an actual position (71, 72), a compensating roller (52) and an apparatus for generating a nominal position (57, 56, 54, 10, 58, 60, 61, 63, 64, 66, 67, 68, 69, 70), and in that the control component (34) is arranged to be variably drivable in dependence on the speed of rotation of the main drive of the printing machine.
2. Regulating arrangement (48) in an apparatus according to Claim 1, characterised in that for regulating the return of a deflectable tensioning roller (52), wrapped around by material web, into a precalculated nominal position, in dependence on a tensioning signal (U_φ) generated by a deflection (φ) of the tensioning roller, three regulating blocks (A, B, C) are arranged parallel, in that the regulating blocks (A, B, C) each have a PT₁ system (76; 81; 88), in that the PT₁ system (76) of the regulating block (A) is switched parallel with a P system (77), in that a summing point (79) is provided which positively links the output signals of the regulating circuit elements (76, 77), in that behind the summing point (79) a further P system (78) is disposed, in that behind the PT₁ system (81) of the regulating block B a summing point (86) is disposed, in that behind the summing point (86) a P system is provided, whereof the output signals are routed at a branch point (87) to the summing point (86) via a negative feedback loop, in that the negative feedback loop has an I system, in that behind the summing point (87) a non-linear regulator circuit element (84) is disposed, in that behind the PT₁ system (88) of the block (C) a non-linear regulator circuit element (89) is disposed, in that the output signal: (U_B, U_C) of the regulating blocks (B, C) are linked by means of a recognition logic circuit (93, 94, 96), in that behind the recognition logic circuit (93, 94, 96) a non-linear regulator circuit element (98) is disposed, in that an output signal (U_D) of the regulating block (D) which contains the recognition logic circuit (93, 94, 96) is multiplicatively linked with an output signal (U_A) of the regulating block (A), in that the voltage signals (U_A, U_D) linked to one another are routed to a servo component (47, 46) for a servo gear (39), in that the servo gear (39) controls a control component (34) of a differential gear (24) driving the draw roller (8).
3. Apparatus according to Claim 1, characterized in that the gear (39) is manually adjustable by means of a handwheel (40).
4. Apparatus according to Claim 1 to 3, characterized in that for the adjustment of the gear (39) a continuously adjustable and reversible servo motor (46) is provided.

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