EP0799785A2 - Control device for the pile lifting drive of a sheet processing machine - Google Patents

Abstract

The motor (6) and adjacent control (7) in front of it, which moves the stack support plate (1). A meter in the form of an angle transmitter (9) is connected to the stack lifting drive mechanism and has a rotor emitting a signal corresponding to the position of the stack support plate. The signal is conveyed to the control for moving the stack support plate to the pre-set desired position. The control has an input appliance (11) giving the actual position of the stack support plate after the measurement has been taken. The meter has a calculator (10) to which the measurement is conveyed.

Description

The invention relates to a control for the stacking stroke drive of a sheet processing machine according to the preamble of claim 1.

In sheet-fed offset printing machines, the sheets to be printed are removed from the top of a sheet stack, fed to a system via a feed table, and from there to a first printing unit. The printed sheets are deposited in the delivery on the top of a sheet stack in the work cycle of the machine. The stack support plates carrying the feeder or delivery stack are mounted so that they can be moved in height in the feeder or delivery arm by means of assigned stack lifting drives. In particular, touching devices are provided which cooperate with the top of the sheet stack, by means of which the stack support plate is moved in the feeder in such a way that the top of the sheet stack remains in an intended height range. The lowering of the stack support plate of the sheet stack in the delivery takes place analogously, the control assigned to the motor of the stack lifting drive also causing the lowering of the stack support plate here in accordance with the signals of the stack height sensing.

The stack support plates in the feeder and delivery of sheetfed offset presses are not only designed for tracking movements to compensate for sheet removal or sheet storage, but can also be moved over longer, especially programmed, distances for automatic or fully automatic stack changes (non-stop operation). Furthermore, when manually changing the stack in the feeder or delivery, the stack support plate has to be moved all the way down to the bottom of the printing room in order to insert a new sheet stack or to remove the full stack from the stack support plate in the delivery. These movements of the stack support plates are also executed after a command input by an operator. On the one hand, the corresponding movement processes for the stack support plates must be carried out as quickly as possible (minimizing the time for a non-stop stack change), on the other hand, for reasons of personal protection or to avoid malfunctions in certain areas, a predetermined maximum speed must not be exceeded. It must also be ensured that the stack support plate is always moved only in the physically possible area in order to avoid damage to the linear drive or the devices in the feeder or delivery arm.

From DE 4 207 305 A1 a device for controlling the stack carrier in printing machines is known, in which the stack carrier is connected to an electrical path measuring device for the continuous detection of its position and for the transmission of measurement data to a programmable computer. According to an embodiment variant disclosed in this document, the displacement measuring device is designed as a rotary potentiometer, which is connected to the rotating element (rotor) of the stack carrier suspension. A connection to the chain wheel shaft of the stacking stroke drive should preferably be provided. The coupling of potentiometers takes place with the interposition of a reduction gear.

In this prior art, the entire travel of the stack support plate is thus transferred to one or more revolutions of the rotating part (rotor) of the potentiometer, so that a measurement value representing the position of the stack support plate is available depending on the position of the rotor. This measured value can then be used in a control downstream of the measurement detection device for moving to predetermined positions of the stack support plate. A disadvantage of this prior art, however, is that the position of the rotary potentiometer with respect to the sprocket shaft must always be readjusted when changing the transmission, transmission parts or the like and when replacing the chain. This point to be observed is also explicitly emphasized in the script.

The object of the present invention is therefore to further develop a control for the stack lifting drive in accordance with the preamble of claim 1, so that with avoidance of the above-mentioned disadvantages, the measured value device for the stacking stroke drive can be brought into a functional state for moving the stacking support plate without time-consuming operating actions.

This object is achieved by the characterizing features of claim 1. Further developments of the invention result from the subclaims.

According to the invention, it is provided that the signal of the control evaluating the displacement measuring device or an upstream evaluation unit in the present position of the stack support plate with the drive motor switched off, a value corresponding to the position of the stack support plate can be entered, this reference value in connection with the current measured value for the others Traversing processes are saved and evaluated. It can thus be provided in particular that the distance between the upper edge of the stacking support plate and, for example, the lower edge of a device of the delivery arm or the delivery housing can be recorded and fed to the control / evaluation unit via a switchable input device (laptop or hand-held terminal). It can be provided that a predetermined value is subtracted from this value, for example by means of a measuring stick or measuring tape. This entered value is then further processed by the control / evaluation unit in such a way that this value, in conjunction with the measured values acquired via the measured value device, is offset to a reference point for the further travel processes. The advantage of the invention is particularly to be seen in the fact that, for example, after replacing the chains or other interventions in the stacking hoist, the stack support plate does not have to be moved into a predetermined position in order to then adjust and fix the measuring system, which is designed in particular as an angle encoder.

With the design according to the invention, it is only necessary to detect the position of the stacking support plate and to feed it to the control or the evaluation unit of the angle encoder via the connected hand terminal or a connected laptop. From this position of the stack support plate to be entered in 'mm' (measured from the top edge of the stack support plate), the controller or the one connected downstream of the angle encoder then determines Evaluation unit in connection with the parameterization with regard to the maximum travel height of the stack support plate, other equipment features (machine or feeder and / or boom on base etc.) and the angle value currently supplied by the angle encoder in particular at the time of the measured value input the starting point for all further travel processes of the stack support plate. Since it is provided in particular to design the measuring device as an angle encoder providing absolute angle values and to connect it via a reduction gear to the shaft of the drive motor or the gear of the stacking lift drive, any position of the stacking support plate within the boom or the feeder corresponds exactly to a digital angle value . If this angular value of the current position of the stacking support plate is then assigned to the measured value of the stacking support plate to be entered via the hand terminal or laptop, all subsequent travel operations of the stacking support plate can be carried out by the control system, since a corresponding reference has been created.

According to the invention, it is provided that the measured value for creating the above-mentioned reference for the travel processes of the stack support plate is specified via a laptop or hand terminal to be connected. Furthermore, provision can also be made for this measured value to be entered via the control station of the printing press in a separate menu mode or via an input device already available elsewhere in selectable units (for example mm or inches) along with the corresponding conversion. When entering measured values via an already existing input device, a special input menu is then to be provided, the measurement specification for the measured value to be entered being able to be shown on a display. Such a menu can also be used to enter other parameters or settings for the feeder or the delivery arm as well as the corresponding movement processes of the stacking support plate. This applies in particular to an expansion of the travel options if additional devices for in particular an automatic stack change (non-stop operation) are retrofitted.

Fig. 1

prinzipiell die Komponenten eines Stapelhubantriebes im Anleger/Ausleger einer Bogenoffsetdruckmaschine,
und

Fig. 2

die Art und Weise des am Ausleger einer Bogenoffsetdruckmaschine zu erfassenden Meßwertes.

Furthermore, an embodiment of the invention is based on the drawing.
It shows:

Fig. 1

basically the components of a stacking stroke drive in the feeder / delivery of a sheetfed offset printing machine,
and

Fig. 2

the manner of the measured value to be recorded on the delivery of a sheet-fed offset printing press.

A stack 2 of an feeder or delivery arm of a sheet-fed offset printing machine, not shown, located on a stack support plate 1 can be moved vertically via chains 3 connected to the stack support plate 1. The chains 3 are operatively connected to a drivable sprocket shaft 4, which is coupled to a motor 6 via a gear 5. The motor 6 is also assigned an electrically releasable brake, which is not shown in the figure, and in particular manages that when the power is switched off or other emergency or dangerous situations, the stack support plate 1 can be locked in the respective position.

The motor 6, in particular in the form of a brushless DC motor with corresponding electronic commutation, is connected, for example, directly via its shaft and a reduction gear 8 to an angle encoder 9, which supplies absolute values, via a number of lines in the manner of a parallel bus. The reduction of the reduction gear 8 for coupling the angle encoder 9 is such that the entire travel of the stack support plate 1, especially between the floor and a maximum attainable upper position within a feeder or boom, does not quite cause one revolution of the rotor of the angle encoder 9. A movement of the stack support plate 1 between the floor indicated in the figure and a maximum attainable upper position means that the digital values of the angle encoder always assume different values and the positions of the stack support plate 1 clearly represent values. In this embodiment, the angle encoder 9 is direct via the reduction gear connected to the shaft of the motor 6. As already indicated above, the reduction gear 8 can also be attached to the gear 5 of the sprocket shaft 4 or to the sprocket shaft 4. It is decisive according to the invention that the entire travel path of the stack support plate 1 produces less than one revolution of the angle encoder 9 or that the entire travel path of the stack support plate 1 is mapped to an area <360 ° of the rotor of the angle transmitter 9.

According to the invention, the angle encoder 9 is designed as an absolute angle encoder, ie corresponding digital signals can be taken from it on a number of lines supplying binary signals or in the form of a serial data stream directly after switching on the devices, the rotor position (encoder disk) of the latter. The angle transmitter 9 is connected to a downstream evaluation unit 10, via which the current vertical position of the stack support plate 1 within the feeder or delivery arm can be determined after input of a reference value. The input reference value is assigned to the digital angle value currently present when the input is made, so that all positions (positions) of the stack support plate 1 in the feeder / delivery arm can now be determined and approached by specifying a digital angle value. The evaluation unit 10, by means of which the digital signals of the angle encoder 9 are converted in accordance with the information given above, is operatively connected to a controller 7, by means of which the energization of the motor 6 is in accordance with the signals of the angle encoder 9 or its values converted via the evaluation unit 10 to move to predetermined positions of the stack support plate 1. As already indicated above, these traversing processes can be carried out by manual operating commands or also programmed. Furthermore, the controller 7 is not only able to carry out a position control for moving to predetermined positions, but also to control the speed of the travel process, which can be determined from a signal of the angle encoder 9, in order to maintain predetermined speed values. The controller 7 is in operative connection with a controller, not shown, of the printing press, which is indicated in FIG. 1 (arrow). The control 7 of the motor 6 can also be used to control other drive elements of the feeder or boom, which are not yet shown.

According to FIG. 1, an input device 11 in the form of a handheld terminal or laptop with keyboard 12 and a display device 13 (display) can be connected to the evaluation unit 10 connected downstream of the angle encoder 9. This is done via a standardized interface, which is accessible in the area of the feeder or the delivery arm. This interface (plug connection) can also be attached to a bus belonging to the control of the printing press, the evaluation unit 10 of the angle transmitter 9 being connected to this bus system (not shown in FIG. 1).

erhalten wird. In Fig. 2 stellt das Maß A den Abstand von der Unterkante 15 des Auslegers 14 zu der obersten und in Fig. 2 gestrichelt dargestellten Position der Stapeltragplatte 1' dar. Die Größe $\text{x=X-A}$

ist somit der Abstand der aktuellen Position der Stapeltragplatte 1 von der maximal oberen Position innerhalb des Auslegers 14. Der gemäß den voranstehend gemachten Angaben erhaltene Wert x wird sodann über die Eingabevorrichtung 11 der Auswerteeinheit 10 zugeführt, woraufhin diese den eingegebenen Meßwert der aktuellen erfaßbaren Winkelposition des Winkelgebers 9 zuordnet und für die weiteren Positioniervorgänge entsprechend umrechnet.Fig. 2 shows in principle a cantilever 14 of an offset printing machine, not shown. In this exemplary embodiment, it is assumed that after an intervention in the stack lifting mechanism (for example, the chains of the stack support plates 1 have been changed), the stack support plate 1 rests on the floor 16. Then the distance X between the upper edge of the stacking support plate 1 and the lower edge of the cantilever 14 marked with the reference mark 15 is measured by means of a measuring tape or a scale. A predetermined value A is then subtracted from this measured value X, so that the size $\text{x = XA}$

is obtained. In FIG. 2, dimension A represents the distance from the lower edge 15 of the boom 14 to the uppermost position of the stacking support plate 1 ′, shown in broken lines in FIG. 2. The size $\text{x = XA}$

is thus the distance of the current position of the stack support plate 1 from the maximum upper position within the boom 14. The value x obtained in accordance with the information given above is then fed via the input device 11 to the evaluation unit 10, whereupon the latter enters the measured value of the current detectable angular position of the Assigned angle encoder 9 and converted accordingly for the further positioning processes.

Reference list

1

Stack support plate

1'

Stack support plate 1 in the top position

2nd

stack

3rd

Chain

4th

Sprocket shaft

5

Gear (sprocket shaft 4)

6

engine

7

control

8th

Reduction gear

9

Angle encoder

10th

Evaluation unit

11

Input device

12th

keyboard

13

Display device

14

boom

15

Lower edge (extension 14)

16

ground

Claims (5)

Control for the stacking stroke drive of a sheet-processing machine, in particular for the feeder and / or delivery of a sheetfed offset printing machine, with a motor causing the movement of the stacking support plate together with an upstream control and a measuring device coupled to the stacking stroke drive, the measuring device having a rotatable part through which one of the Position of the stack support plate corresponding signal can be formed and the control for moving the stack support plate can be supplied to predetermined target positions,
characterized by
that the controller (7) receives the signal from the measuring device (angle transmitter 9) in connection with a measurement value (X;) which can be entered once via an input device (11) and which shows the position of the stack support plate (1) once. $\text{x = XA}$

) can be fed, and that the control (7) via the motor (6), the stack support plate (1) by means of the input with the measured value (X; $\text{x = XA}$

) calculated signals can be moved according to the specified target positions. Control according to claim 1,
characterized by
that the measuring device (angle transmitter 9) is followed by an evaluation unit (10), which is the measured value (X;) representing the position of the stack support plate (1) via the input device (11). $\text{x = XA}$

) can be entered, and which the signals of the measuring device (angle encoder 9) in connection with the measured value (X; $\text{x = XA}$

) for the further positioning processes converted to the controller (7). Control according to claim 2,
characterized by
that the input device (11) is designed as a handheld terminal or laptop and can be temporarily connected to the evaluation unit (10) via an intended interface. Control according to one of the preceding claims,
characterized by
that as the position of the stack support plate (1) reproducing measured value (X; $\text{x = XA}$

) the distance (x = $\text{XA}$

) the actual position (X) of the stack support plate (1) to the uppermost position of the stack support plate (1 ') in the hoist can be input and further processed via the input device (11). Control according to one of the preceding claims,
characterized by
that the measuring device is designed as an angle encoder (9) which is connected via a reduction gear to the motor (6) of the stacking stroke drive, the reduction of the reduction gear (8) being chosen such that the total maximum travel path of the stack support plate (1) causes less than one revolution of the rotor of the angle encoder (9).

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