CN110667247B

CN110667247B - Method for operating a turning device of a printing press

Info

Publication number: CN110667247B
Application number: CN201910596663.7A
Authority: CN
Inventors: A·云格尔; T·格贝尔; S·埃克哈特; R·施罗德
Original assignee: Heidelberger Druckmaschinen AG
Current assignee: Heidelberger Druckmaschinen AG
Priority date: 2018-07-03
Filing date: 2019-07-02
Publication date: 2022-10-28
Anticipated expiration: 2039-07-02
Also published as: CN110667247A; DE102019207708A1

Abstract

The invention relates to a method for operating a turning device (1) of a printing press, wherein a sheet (4) is transferred from a storage cylinder (2) having a tensioning suction (5) to a turning cylinder (3) having a gripper (10) and the tensioning suction (5) is ventilated. The ventilation time of the tensioned suction device (5) is controlled by a valve, which is set according to at least one parameter. The valve may be a switching valve (18) or a rotating valve (19). The valve can be controlled by an electronic controller (17) to set the ventilation time.

Description

Method for operating a turning device of a printing press

Technical Field

The invention relates to a method for operating a turning device of a printing press, wherein a sheet is transferred from a storage cylinder with tensioned suction devices to a turning cylinder with gripper suction devices, and the tensioned suction devices are ventilated.

Background

In the turning device, the sheet is held at its rear edge by means of tensioning suction, which in this case performs a tensioning movement (Spannbewegung) in order to tension the sheet.

DE 10 2007 049 643 B4 describes a turning device in which the underpressure at the so-called suction grippers of the storage drum is switched off and these suction grippers are ventilated when the angle of rotation is 350 °. When the angle of rotation is 360 °, the trailing edge of the sheet reaches the transfer center between the storage drum and the reversing drum and is taken over by the gripper system of the reversing drum.

DE 10 2015 209 692 A1 describes a turning device in which the storage drum has a so-called suction path for tensioning the sheets longitudinally or transversely. An air control device is provided, by means of which the suction air applied to the suction devices can be influenced.

Disclosure of Invention

The object of the invention is to provide a method with better flip register retention (wendepassserhalitgkeit).

The object is achieved by a method for operating a turning device of a printing press, in which a sheet is transferred from a storage cylinder with a tensioned suction to a turning cylinder with a gripper, and the tensioned suction is ventilated, characterized in that the ventilation times of the tensioned suction are controlled by valves, which are set as a function of at least one parameter.

In the method according to the invention, the effective holding force of the tensioning suctions during sheet transfer is optimally adapted to the effective holding force of the gripper grippers, so that good turnover register retention is ensured.

There are many possible modifications of the method according to the invention:

the parameters may be printing material-specific parameters, such as: thickness of the sheet, or permeability of the sheet.

The above-mentioned or another parameter according to which the valve is adjusted may be a machine-specific parameter, such as: the presence of suction cups on the tensioning suction can be attached to these tensioning suction as required, or for example the machine speed.

The valve can be driven and controlled by an electronic controller to adjust the ventilation time.

The valve may be a rotary valve or a switching valve.

These tensioning suctions may be rotary suctions, wherein the tensioning movement is a rotation. Alternatively, the tensioning suctions may be glide suctions, wherein the tensioning movement is a translation. This translation or a component thereof may be oriented parallel to the axis of rotation of the storage drum.

These gripper grippers may be pincer grippers each having two pivotable gripping jaws. The gripper jaws can execute an oscillating movement with respect to the reversing cylinder together with the sheet clamped therein. Each of the two clamping jaws can be mounted so as to be pivotable relative to the base body of the reversing drum.

The suction cups already mentioned may consist of rubber. These suction cups can each be configured as a rubber suction collar (Manschette). Such rubber may be a rubber elastic plastic.

Drawings

The improvement also results from the following description of two exemplary embodiments and from the drawings, in which:

FIG. 1: the sheet is transferred from the storage cylinder to the turning cylinder at its rear edge; and

FIG. 2: the trailing edge of the sheet is held simultaneously by a tensioning suction of the storage cylinder and a gripper of the reversing cylinder.

Detailed Description

Fig. 1 shows a reversing device 1 of a sheet-fed printing press, which reversing device 1 comprises a storage cylinder 2 and a reversing cylinder 3. The sheet printing press is operated in a front-side and a rear-side printing mode, in which the sheet 4 is turned over by the turning device 1. The turning device 1 can be switched to the front side printing mode without turning the sheet 4. The storage drum 2 has tensioned suction devices 5, which tensioned suction devices 5 are arranged in a parallel arrangement with respect to the axis of rotation of the storage drum 2.

Fig. 2 shows the tensioning suction 5 and the gripper 10 in detail. The figures show: these tensioning suctions 5 are designed as rotary suctions which carry out a tensioning movement 6 in order to tension the sheets 4. This tensioning movement is a rotation about the axis of rotation 7 of the tensioning suction 5. These tensioning suctions 5 are each equipped with a suction cup 8 made of rubber, which suction cup 8 is configured as a collar. One or more suction openings 9 of each tensioned suction means 5 are arranged eccentrically with respect to the axis of rotation 7.

The convertible cylinder 3 has gripper grippers 10, which grippers 10 are arranged in a parallel alignment with respect to the axis of rotation of the convertible cylinder 3. These gripper grippers 10 are configured as pincer grippers having a first jaw 11 and a second jaw 12, respectively. The two clamping jaws 11,12 are mounted so as to be pivotable relative to a base body 13 of the tumble cylinder 3.

The tensioning suctions 5 are attached by a guide system 14 to a suction air generator 15, which suction air generator 15 loads the tensioning suctions 5 with a vacuum applied on the suction openings 9. A rotary valve 19 controlled by the electronic controller 17 is integrated in the pilot system 14. The rotary valve 19 controls the cyclic vacuum application of the tensioning suction devices 5 in the sheet 4 transport cycle (Transporttakt). The rotary valve 19 comprises an adjusting device 20, by means of which adjusting device 20: in which angle of rotation of the storage drum 2 a so-called suction air cut-off (sauglufibris) is performed. That is to say, the control device 20 can be used to calibrate the ventilation times of the tensioning suction 5 with reference to the phase of the storage drum 2. For this purpose, the regulating device 20 is driven by an electric motor connected to the control unit 17.

If an electrically actuable switching valve 18 is provided, via which the guide system 14 and thus the tensioning suction 5 are periodically connected to the ambient air at the delivery rate of the sheets 4, the regulating device 20 can be dispensed with. Accordingly, a switching valve 18 is actuated by the controller 17, which switching valve 18 can be, for example, a magnetic valve.

In both alternatives or variants (adjusting device 20 or switching valve 18) which are shown together in the same figure, the operator can carry out the setting required for the ventilation time of the tensioning suction device 5 at the control unit 17 (for example, the control console of the control unit 17) as a function of one or more parameters or influencing factors. Such parameters may be, for example: whether these suction cups 8 are fitted on the tensioned suction apparatus 5 or not (and in the latter case it should be unnecessary to operate these suction cups 8). Other parameters may be: the composition of the sheet 4, i.e. how air-permeable the paper or cardboard is, is the so-called suction tendency of the printing material (Bedruckstoff-durchsingeigung), and the surface roughness of the sheet 4. The setting of the ventilation time required for tensioning the suction device 5 can also be carried out automatically or on a programmed basis by a program running in the control device 17.

These tensioning suction devices 5 tension the sheet 4 before the sheet 4 is transferred to the gripper 10. When tensioned, these tensioning suction devices 5 hold the sheet 4 stationary at a point close to the sheet trailing edge. The tensioning suctions 5 are subjected to vacuum by the suction air generator 15, so that the tensioning suctions 5 suck the sheet 4 during the tensioning movement 6, and the tensioning suctions 5 each carry out the tensioning movement 6 about the axis of rotation 7.

Fig. 1 and 2 show the situation at the point in time at which the trailing edge of the sheet 4 is held stationary by the gripper grippers 10 and at the same time by the tensioning suctions 5 during its transfer from the storage cylinder 2 to the reversing cylinder 3. These gripper grippers 10 sink into the cylinder channel 16 of the storage cylinder 2 and hold the trailing edge of the sheet 4 clamped between the first and second clamping jaws 11, 12.

After the moment shown in the figure, these rollers 2,3 continue to rotate in the direction of rotation indicated by the arrow. In this case, the gripper grippers 10 are pivoted relative to the substrate 13 from a position in which the gripper jaws 11,12 (viewed in the direction of rotation of the tumble cylinder 3) point forward to a position in which the gripper jaws 11,12 point in the opposite direction (that is to say rearward with reference to the direction of rotation of the tumble cylinder 3).

After the point in time shown in the drawing, the sheet 4 is removed from the tensioned suction elements 5 by the gripper grippers 10. The sheet edge which is the trailing edge before the sheet 4 is transferred from the tensioning suctions 5 to the gripper jaws 10 is located in front in the sheet transport direction after the sheet 4 is transferred. That is, the turnover device 1 operates according to the principle of so-called rear edge turnover (hinderkantenwendung). The tensioning movement 6 and the vacuum application to the tensioning suction 5 take place in the manner described above for each sheet 4 to be turned over one after the other.

The invention is advantageous in that the adjustable ventilation times of the tensioning suction devices 5 or their suction air lines enable the removal forces acting between the sheet 4 and the tensioning suction devices 5 to be reduced so strongly during the transfer of the sheet 4 from the storage cylinder 2 to the reversing cylinder 3 that they do not lead to the sheet 4 slipping into the gripper jaws 10 and to a reversal register error. Here, the operator can adjust the ventilation timing to an optimum value by checking the flip register.

List of reference numerals

1. Turning device

2. Storage drum

3. Turnover drum

4. Sheet of paper

5. Tensioning aspirator

6. Tensioning movement

7. Axis of rotation

8. Suction cup

9. Suction opening

10. Clamping gripper

11. First clamping jaw

12. Second clamping jaw

13. Substrate

14. Guidance system

15. Suction air generator

16. Roller channel

17. Controller for controlling a motor

18. Switching valve

19. Rotary valve

20. Adjusting device

Claims

1. Method for operating a turning device (1) of a printing press, wherein a sheet (4) is transferred from a storage cylinder (2) having a tensioned suction means (5) to a turning cylinder (3) having a gripper (10), and wherein the tensioned suction means (5) is ventilated, characterized in that the tensioned suction means (5) is attached to a suction air generator (15) by means of a guide system (14), wherein a valve is provided in the guide system (14), by means of which valve the ventilation time of the tensioned suction means (5) is controlled in such a way that the suction air is periodically switched off or is periodically connected to ambient air in the guide system (14), wherein the valve is set as a function of at least one parameter of the printing press and/or of the sheet (4).

2. The method of claim 1, wherein the parameter is a substrate-specific parameter.

3. Method according to claim 2, characterized in that the parameter is the thickness of the sheet (4).

4. Method according to claim 2, characterized in that the parameter is the air permeability of the sheet (4).

5. The method of claim 1, wherein the parameter is a machine specific parameter.

6. The method of claim 5, wherein the parameters are: whether or not a suction cup (8) is present on the tensioning suction device (5) which can be placed on the tensioning suction device (5) as required.

7. The method of claim 5, wherein the parameter is a machine speed of the printing press.

8. Method according to any one of claims 1 to 7, characterized in that said valve is actuated by an electronic controller (17) to set said ventilation time.

9. The method according to any of claims 1 to 7, characterized in that the valve is a rotary valve (19).

10. The method according to any one of claims 1 to 7, characterized in that the valve is a switching valve (18).