EP0503623A1 - Device for regulating the air blast demand of the air nozzles of a sheet feeder in a rotary printing machine - Google Patents

Abstract

In a device for regulating the compressed air demand of the air nozzles (7, 8) of a sheet feeder (38) in a rotary printing machine (37), the object is to make available the required quantity of compressed air in accordance with a central input. According to the invention, this is achieved in that a regulating valve (3) is arranged between the compressed air generator (1) and the compressed air user (7, 8), which control valve is connected to a computer (10) of the machine control panel, in that the computer is connected to sensors (5, 15) for pressure and rotational speed of the machine and to a keyboard (47), in that production data can be entered into the computer which, via characteristic curves (43, 44, 46) for type and weight per unit area of the printing carrier, influence a setting device (16, 29) of the regulating valve (3). <IMAGE>

Description

Device for regulating the blowing air requirement of the separating nozzles in a sheet feeder of a sheet-fed rotary printing machine

The invention relates to a device for regulating the blown air requirement of the separating nozzles in a sheet feeder of a sheet-fed rotary printing press according to the preamble of patent claim 1.

For the supply of blown air for sheet feeders in sheet-fed rotary printing presses, it is known to use pressure regulators which keep the air pressure for the blown air nozzles, such as loosening blowers and separating blowers, at a preset value. The preset value depends on the type and nature of the fabric to be printed.

Such a type of pressure regulator is described, for example, in DE-GM 77 11 340, where a quantity of air that is temporarily not required is released to the environment through a valve. A valve disk is lifted against the adjustable force of a spring by an increased air pressure from the valve seat and this amount of air, which is temporarily not required, is released into the environment.

With such a pressure regulator, however, it is not possible to regulate such a changed air requirement, which arises whenever the operating speed of the printing press and thus of the sheet feeder is changed, since there is no coupling to the machine speed.

It is therefore customary in rotary printing machines to connect throttle valves to the pressure regulator mentioned in order to meet a changed requirement for blown air at a changed speed of the sheet-fed rotary printing machine.

This is according to DE-PS 26 43 381 via a valve for metering the start-up blown air supplied to a sheet separating device of a sheet feeder, with a control slide connected via an air inlet opening to a pressure source, which has an air outlet opening leading to the sheet separating device and an air outlet opening leading to the outside when starting up or stopping the sheet feeder by means of a control element which can be actuated as a function of the machine speed, can be reversed up or down, achieved in that the control element is designed as a rotatably mounted cock plug which is diametrically penetrated by a through hole which is reached when the set value is reached Final speed coaxially to the air inlet opening and the diametrically opposite air outlet opening leading to the sheet separation device is aligned.

However, this metering valve has the disadvantage that it has to be constantly adjusted, since the volume flow depends on the cross sections of the other consumers. This cross-section changes because loosening and separating blowers are acted on intermittently, ie alternatively with blown air, which leads to a changing or pulsating air consumption. This has an unfavorable effect on the loosening blower, which is sometimes subjected to too little and once too much blowing air, which is either not for proper loosening or leads to blowing. In addition, a change in the cross section of a single blowing nozzle affects the other nozzles, which requires manual readjustment.

The invention has for its object to provide a device for controlling the blown air requirement for separating nozzles for a sheet feeder of a rotary printing press, with which the required amount of blown air is automatically made available after a central input to the selected properties of the print carrier, for example the grammage of the print carrier.

According to the invention this object is achieved by the characterizing part of claim 1.

As a result of the creation of a device according to the invention for regulating the amount of air or the air pressure, it is achieved that both the basic requirement of the required amount of air with the required air pressure for supplying the blowing nozzles can be regulated in accordance with the type and nature of the material to be printed, and also a speed-dependent regulation of the requirement for blowing air for the blow nozzles. Here, the control effect of the device according to the invention ensures that both pulsating air flows on the blowers and manual readjustment when individual valves are adjusted are avoided. Rather, it is only necessary to enter the required production data, such as the grammage and type of substrate and the machine speed, on the keyboard of the computer in the machine control center.

Fig. 1

die Prinzipdarstellung der erfindungsgemäßen Einrichtung zum Regeln des Blasluftbedarfes;

Fig. 2

die schematische Darstellung eines Regelventils im Schnitt;

Fig. 3

die schematische Darstellung einer weiteren Ausführungsform eines Regelventils im Schnitt;

Fig. 4

die schematische Seitenansicht einer Bogenrotationsdruckmaschine mit der Darstellung eines Saugkopfes im Bogenanleger;

Fig. 5

die Ansicht A nach Fig. 4;

Fig. 6

eine schaubildliche Darstellung von verschiedenen Ventilkennlinien in Abhängigkeit des Bedruckstoffes zur Regelung des Ventils nach Fig. 3.

Fig. 7

eine schaubildliche Darstellung eines Funktionsdiagrammes der Arbeitsweise des Maschinenleitstandes

The invention is intended to several Embodiments are shown. The associated drawings show:

Fig. 1

the schematic diagram of the device according to the invention for regulating the blown air requirement;

Fig. 2

the schematic representation of a control valve in section;

Fig. 3

the schematic representation of another embodiment of a control valve in section;

Fig. 4

the schematic side view of a sheet-fed rotary printing press with the representation of a suction head in the sheet feeder;

Fig. 5

the view A of FIG. 4;

Fig. 6

3 shows a graphical representation of various valve characteristics as a function of the printing material for regulating the valve according to FIG. 3.

Fig. 7

a graphical representation of a functional diagram of the operation of the machine control center

1, the basic illustration shows a compressed air generator 1 which is connected to a control valve 3 via a line 2. The control valve 3 is connected via further lines 4 and throttles 6 both to separating blowers 7 and to loosening blowers 8 of a sheet feeder 38 of a sheet-fed rotary printing press 37.
In front of the separating blowers 7 and loosening blowers 8, a control valve 9 is arranged, which the separating blowers 7 and Loosening blower 8 is supplied with blowing air in cycles. 1 shows a machine control station 10 with an integrated computer, which is connected on the one hand to an input device or keyboard 47 and on the other hand to a pressure sensor 5 located in line 4. The machine control station 10 is also connected to the valve 3 via an amplifier 45, wherein the valve 3 can be designed in the manner shown in FIG. 2 or 3. The amplifier 45 can be designed, for example, as a bipolar amplifier with reversal of the direction of rotation.

2, a control valve 3 is shown, which is housed in a housing 11. A cylindrical shaft 12 protrudes from the cover part of the housing 11 into the housing interior, which is provided centrally in the interior with a threaded bore 13 through which a threaded spindle 14 is guided, which has a handwheel 16 at its end. Two exhaust air openings 17 are provided on the side parts of the housing 11. The bottom part of the housing 11 has an inlet opening 18 which is connected to a blown air duct 19 which is guided on the underside of the housing 11. The inlet opening 18 has a beveled valve seat 21 which can be closed by a valve plate 22 and can be opened against the force of a coil spring 23. The coil spring 23 is arranged between the valve plate 22 and a spring seat 24 fastened to the threaded spindle 14. The shaft 12 of the housing 11 has a thread 26 on its outside, on which a toothed wheel 27 is guided.

The gear 27 meshes with a further gear 28 which can be driven by a motor 29. The gear 27 is adjustable via the motor-driven gear 28 on the thread of the shaft 12 via a helical spring 31 also against the valve plate 22 in the direction of arrow H.

3 shows a schematic sectional illustration of a further embodiment of a control valve 3, in which the cover part of the housing 11 has a threaded bore 31, in which a threaded bushing 32 is guided, for receiving the threaded spindle 14. Between the spring seat 24 of the threaded spindle 14 and the spring seat 24 of the threaded spindle 14 and the valve plate 22, a coil spring 33 is arranged. The threaded bush 32 has at its end located in the housing 11 a gear 34 which can be driven via the motor-driven gear 28.

The motor 29 according to FIGS. 2 and 3 receives its manipulated variable via the machine control station 10 according to FIG. 1. According to FIG. 4, the schematic side view of a sheet-fed rotary printing press 37 is shown with a sheet feeder 38 and a suction head 39 located thereon.
4 and 5, the separating blower 7 and loosening blower 8 are fastened to a first cross member 41, which is connected to the suction head 39 via a second cross member 42. 1, the separating blowers 7 and loosening blowers 8 are connected via lines not shown in FIG. 5. The separation and loosening blower 7; 8 act laterally on the upper edge of a sheet stack 40.

6 shows a graphical representation of various characteristic curves for the control valve 3, the characteristic curve 43 for cardboard (larger than 150 g / m²), the characteristic curve 44 for sheets of medium grammage (approx. 70 to 90 g / m²) and the characteristic curve 46 for thin printing paper (less than 40 g / m²) is shown as a representative. There are many more characteristic curves, but they are not shown here.

The operation of the device according to the invention is as described below.

The blown air duct 19 of the control valve 3 receives blown air from the compressed air generator 1 via the line 2, which blown air is supplied by the blown air consumers, namely the separating blowers 7 and the loosening blowers 8 in accordance with the production conditions. According to FIG. 2, the coil spring 23 is first pressed against the valve plate 22 with valve seat 21 using a first adjusting device via the handwheel 16. The handwheel 16 can be moved in the direction of the arrow K. In the direction of arrow I, the blown air is guided into the blown air duct 19. The preset force of the coil spring 23 is dimensioned so that it corresponds to the air requirement of the separating blower 7 and the loosening blower 8 when starting. If the air pressure is too high, the valve plate 22 is lifted out of the valve seat 21 against the force of the coil spring 23 and part of the air quantity I escapes at J through the inlet opening 18 and the exhaust air openings 17 into the open. The exhaust air openings 17 can be connected to damping devices in order to discharge those that are no longer required Blowing air not to exceed a certain noise level.

As a result of the changing air requirement of the separating blowers 7, which are alternatively supplied with blown air via the control valve 9, and the increasing air requirement when the printing machine rotates at an increased speed, the second actuating device, consisting of a gear with the components thread 26 on the shaft 12, becomes the gear wheels 27 , 28 and the motor 29, with a manipulated variable L.

This manipulated variable, represented by L in FIG. 1, comes from the computer of the machine control center of the rotary printing press and the gear can alternatively adjust the coil spring 30 in the direction of arrow H. 1, the production data are entered into the computer of the machine control center 10 via a keyboard 47. Such data are, for example, the production speed in sheets / hour and the type and grammage of the printing material. The grammage of the printing material or of the printing medium, for example paper, is given in grams per square meter. The motor 29 according to FIG. 2 receives a manipulated variable L. The actual state is given to the computer of the machine control center 10 via the pressure sensor 5. This in turn compares the actual state with your target state and regulates with the aid of a characteristic curve 43 to 46 until the actual state corresponds to the target state. In the same way, the computer of the machine control center 10 also evaluates the actual state, which is determined by a speed sensor 15 machine drive, not shown, is reported. This signal is designated M in FIG. 1.

As a result, a second force against the valve plate 22 is adjustable, i. H. when there is a high demand for air, the valve plate 22 is pressed against the valve seat 21 and, when the demand for air is low, the additional force is kept low or not effective via the spring 30, so that unneeded air can escape to the outside in the direction of the arrow J.

A pneumatic cylinder with a proportional valve can also be used as the actuating device instead of the gearbox mentioned.

3, the valve plate 22 is preset via the handwheel 16 against the force of the spring 33 in accordance with the type and nature of the materials to be printed. Thus, the first actuating device consists of the handwheel 16 with the threaded spindle 14, which is held in the threaded bush 32 of the housing 11.

The increased blown air requirement due to the increase in the speed and the changing air requirement of the separating blower 7 via the control valve 9 is set via a signal which the motor 29 receives. The signal comes from the computer of the machine control center 10 of the rotary printing press. The motor 29 thus alternatively moves the spring 33 via the gear 28, 34, 14 in the direction of the arrow H in accordance with the requirements.

Pneumatic cylinders with a proportional valve can also be used as actuators.

However, it is also possible to omit the first actuating device shown in FIG. 3 and to transmit the signals K, L to the spring 33 through the second actuating device. The signals L, K in turn come from the computer of the machine control center 10 of the rotary printing press. For example, cardboard could be driven, which is entered via the keyboard 47. Characteristic curve 44 can be considered, for example. With a possible production speed of 14,000 sheets / hour, 72 percent of the total volume flow of blowing air generated by the blowing air system is required. The production speed is also entered using the keyboard or manually controlled by the printer. The keyboard 47 or input device can also be designed, for example, as a reader for a magnetic card to be inserted. Other automatic value recording devices can also be used.

7, the automatic operation of the machine control station 10 will be discussed again in connection with FIGS. 1 and 6.

The software of the machine control center 10 works according to a function diagram (FIG. 7) according to which all steps 51-76 are carried out automatically.

(n) oder in diskreten Stützstellen vorliegen kann.By entering z. B. the grammage of the printing material in step 51, the input is classified in steps 52 and 53 and the characteristic 44, 43 or 46 is accordingly selected in the corresponding steps 54, 56 or 57. This characteristic curve is read in step 58, this in the form of a function

(n) or in discrete support points.

_soll berechnet. Der Schritt 63 dient zur Bestimmung des notwendigen Druckes p_soll in Abhängigkeit des Volumenstromes

_soll. Der Vergleich der SOLL- und IST-Werte des Druckes erfolgt in den Schritten 67 und 68. Anschließend wird eine Motorbewegung (Schritt 69 oder 71) zur Veränderung der Federkraft ausgelöst, woraufhin nochmals der momentane Druck p_ist im Schritt 66 ermittelt wird. Diese Schleife 66 bis 72 wird durchlaufen bis der Istwert dem Sollwert des Druckes entspricht. Ist der Abgleich des Druckes abgeschlossen, wird in den Schritten 73 und 74 die derzeitige Maschinengeschwindigkeit n_ist2 überprüft. Ist die Maschinengeschwindigkeit unverändert, d. h. n_ist1 = n_ist2, dann wird die Routine bzw. der Ablauf des Druckabgleiches (Schritt 66 - 72) durchlaufen, andernfalls wird die Routine bzw. der Ablauf der Berechnung des notwendigen Volumenstromes und entsprechenden Druckabgleiches wiederholt (Schritt 61 - 72).In step 59, the sensor 15 delivers signals, from which the machine speed is determined in step 61. In step 62, the necessary volume flow is determined using this machine _speed n _ist1

_{should be} calculated. Step 63 serves to determine the necessary pressure p _target as a function of the volume flow

_should . The SET and ACTUAL values of the pressure are compared in steps 67 and 68. A motor movement (step 69 or 71) is then triggered to change the spring force, whereupon the instantaneous pressure p _{ist is} determined again in step 66. This loop 66 to 72 is run through until the actual value corresponds to the nominal value of the pressure. If the adjustment of the pressure is completed, the current machine _speed n _{actual2 is} checked in steps 73 and 74. If the machine speed is unchanged, ie n _ist1 = n _ist2 , the routine or the sequence of the pressure adjustment (steps 66 - 72) is run through, otherwise the routine or the sequence of the calculation of the necessary volume flow and corresponding pressure adjustment is repeated (step 61 - 72).

Parts list

1

Compressed air generator

2nd

management

3rd

Control valve

4th

management

5

Pressure sensor

6

throttle

7

Separator

8th

Loosening blower

9

Control valve

10th

Machine control center

11

casing

12

shaft

13

Tapped hole

14

Threaded spindle

15

sensor

16

Handwheel

17th

Exhaust vent

18th

Inlet opening

19th

Blow air duct

20th

-

21

Valve seat

22

Valve plate

23

Coil spring

24th

Feather seat

25th

-

26

thread

27th

gear

28

gear

29

engine

30th

feather

31

Tapped hole

32

Threaded bush

33

Coil spring

34

gear

35

-

36

Tapped hole

37

Sheet-fed rotary printing machine

38

Sheet feeder

39

Suction head

40

Sheet stack

41

traverse

42

traverse

43

curve

44

curve

45

amplifier

46

curve

47

Keyboard / input device

48

-

49

-

50

-

51

Process steps, functional diagram

52

Process steps, functional diagram

53

Process steps, functional diagram

54

Process steps, functional diagram

55

Process steps, functional diagram

56

Process steps, functional diagram

57

Process steps, functional diagram

58

Process steps, functional diagram

59

Process steps, functional diagram

60

Process steps, functional diagram

61

Process steps, functional diagram

62

Process steps, functional diagram

63

Process steps, functional diagram

64

Process steps, functional diagram

65

Process steps, functional diagram

66

Process steps, functional diagram

67

Process steps, functional diagram

68

Process steps, functional diagram

69

Process steps, functional diagram

70

Process steps, functional diagram

71

Process steps, functional diagram

72

Process steps, functional diagram

73

Process steps, functional diagram

74

Process steps, functional diagram

75

Process steps, functional diagram

76

Process steps, functional diagram

H

Arrow direction

I.

Arrow direction

J

Arrow direction

K

Impulse f. Basic setting

L

Manipulated variable / signal

Claims (13)

Device for regulating the blown air requirement of the separating nozzles (7; 8) in a sheet feeder (38) of a sheet-fed rotary printing machine (37) via control valves (9), characterized in that in the line (2; 4) between a blown air generator (1) and the blown air consumers (7; 8) with the upstream control valves (9) a control valve (3) is arranged, which is connected to a computer of the machine control center (10) via an amplifier (45) that the computer with sensors (5; 15) for pressure and machine speed and an input device (47) is connected that the computer can be supplied with production data which, via characteristic curves (43; 44; 46) for grammage and / or type of the print medium, an adjusting device (16; 29) of the control valve (3) influence. Device according to claim 1, characterized in that a first adjusting device is arranged in a housing (11) of the valve (3), which acts by means of the force of the spring (23) against the valve disk (22), which acts in the presence of an overpressure in the Blown air duct (19) an inlet opening (18) releases to discharge the unneeded blown air that a second actuating device is present, which is independent of the first actuating device (13; 14; 16; 24) also with the force of a spring (30) against the valve disk (22) works. Device according to claim 1 and 2, characterized in that the first actuating device in the valve (3) consists of a threaded spindle (14) with a handwheel (16) which is guided in a threaded bore (13) of the housing (11) and on its ins Inside the housing (11) projecting end has a spring seat (24) for receiving the spring (23). Device according to claims 1 to 3, characterized in that the second adjusting device in the valve (3) for adjusting the force of the spring (30) against the valve disk (22) consists of a gear (26; 27; 28; 29). Device according to claims 1 to 3, characterized in that the second adjusting device for adjusting the force of the spring (30) against the valve disk (22) consists of a pneumatic cylinder with a proportional valve. Device according to claims 1 and 2, characterized in that the first and the second adjusting device have a common spring (33) which can be acted upon by the two adjusting devices. Device according to claim 1, 2 and 6, characterized in that the first adjusting device consists of a threaded spindle (14) with a handwheel (16) which is in a threaded bush (32) of the housing (11) held and at its end projecting into the interior of the housing (11) has a spring seat (24) for receiving the spring (33). Device according to claim 1, 2, 6 and 7, characterized in that the second actuating device consists of a gear (14; 34; 28; 29) for adjusting the force of the spring (33) against the valve plate (22). Device according to claim 1, 2, 6 and 7, characterized in that the second adjusting device for adjusting the force of the spring (33) against the valve plate (22) consists of a pneumatic cylinder with a proportional valve. Device according to claims 1 to 3, 6 and 7, characterized in that the first adjusting device for regulating the air flow for the blowing nozzles (7; 8) is adjusted by hand in accordance with the type and nature of the printed material. Device according to claim 1, 2, 4, 5, 6, 8 and 9, characterized in that the second actuating device for regulating the air flow for the blower nozzles (7; 8) receives a signal from the computer of the machine control station according to the speed of the sheet feeder ( 10). Device according to claim 1, 9 and 10, characterized in that the first and second actuating device for regulating the air flows for the blowing nozzles (7; 8) receive signals from the computer of the machine control center (10). Device according to claim 1, 2 and 10 to 12, characterized in that the first and second adjusting devices for regulating the air flows are combined in one adjusting direction.

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