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DE-102019127358-B4 - Method for depositing sheets in a delivery tray of a sheet-processing machine

DE102019127358B4DE 102019127358 B4DE102019127358 B4DE 102019127358B4DE-102019127358-B4

Abstract

A method for depositing sheets in a delivery tray (1) of a sheet-processing machine with a non-stop device (11), wherein sheets are grasped at the leading edge by a conveying system (2) in a sheet conveying direction (BFR) via a sheet brake (7) to a stacking area and released above the stacking area, wherein the released sheets are decelerated by discontinuously rotating brake elements (8) of the sheet brake (7), wherein for non-stop stack removal at least one support element (18) is first moved into the stacking area depending on the angle and subsequently, to form an auxiliary stack, an auxiliary stack carrier (12) is moved by the non-stop device (11) into the stacking area in the sheet conveying direction (BFR), characterized in that the at least one support element (18) is moved into the stacking area in such a controlled manner that it reaches its working position at a machine angle (W1) at which a sheet trailing edge is in a determined desired position (P1) with respect to the brake elements (8) of the bow brake (7), wherein the bow trailing edge leaving the brake elements (8) is the first bow trailing edge to be supported by the at least one support element (18).

Inventors

  • Martin Riese
  • Stephan Weisheit
  • Volker Kessler
  • Heinz Michael Koch
  • André Rossa
  • Volker Taschenberger

Assignees

  • KOENIG & BAUER AG

Dates

Publication Date
20260513
Application Date
20191010

Claims (10)

  1. A method for depositing sheets in a delivery (1) of a sheet-processing machine with a non-stop device (11), wherein sheets are grasped at the leading edge by a conveying system (2) in a sheet conveying direction (BFR) via a sheet brake (7) to a stacking area and released above the stacking area, wherein the released sheets are decelerated by discontinuously rotating brake elements (8) of the sheet brake (7), wherein for non-stop stack removal at least one support element (18) is first moved into the stacking area depending on the angle and subsequently, to form an auxiliary stack, an auxiliary stack carrier (12) is moved by the non-stop device (11) into the stacking area in the sheet conveying direction (BFR), characterized in that the at least one support element (18) is moved into the stacking area in such a controlled manner that it reaches its working position at a machine angle (W1) at which a sheet trailing edge is in a determined desired position (P1) with respect to the brake elements (8) of the bow brake (7), wherein the bow trailing edge leaving the brake elements (8) is the first bow trailing edge to be supported by the at least one support element (18).
  2. Procedure according to Claim 1 , wherein the trailing edge of the arc begins to leave the braking elements (8) of the arc brake (7) in the determined desired position (P1).
  3. Procedure according to Claim 1 or 2 , where the determined desired position (P1) has a machine angle-related tolerance of ± 50°.
  4. Procedure according to Claim 1 , 2 or 3 , wherein the determination of the machine angle (W1) is based on a characteristic reference angle (W0) which results from the control of the dynamic movement of the brake elements (8) of the arc brake (7) or is obtained by a brake end sensor.
  5. Procedure according to Claim 1 , 2 , 3 or 4 , wherein the determination of the machine angle (W1) is based on a characteristic reference angle (W0) obtained by a brake end sensor located at the braking end point (P0).
  6. Procedure according to Claim 1 , 2 , 3 , 4 or 5 , wherein the trailing edge of the arc has reached exactly one braking endpoint (P0) at the braking elements (8) of the arc brake (7) at one or the characteristic reference angle (W0).
  7. Procedure according to Claim 1 , 2 , 3 , 4 , 5 or 6 , wherein a start angle (W_Start) is calculated for a control signal of at least one control valve for the at least one support element (18).
  8. Procedure according to Claim 1 , 2 , 3 , 4 , 5 , 6 or 7 , where a start angle (W_Start) for a control signal of at least one control valve for the at least one support element (18) is calculated from the formula: W_Start = W0 + ( Δ s vAblage − t_Tot t_Takt ) ∗ 360 ° , where W0 is the machine angle at which the trailing edge of the sheet is located at the braking end point (P0), where Δs = (P1) - (P0) is the difference between the determined desired position (P1) and the braking end point (P0), where vAblage is the constant residual velocity after the sheet braking has ended at the braking end point (P0), where t_Tot is the reaction time of the support element (18) from the electrical signal until the working position is reached, and where t_Takt is the cycle time of the machine.
  9. Procedure according to Claim 1 , 2 , 3 , 4 , 5 , 6 , 7 or 8 , wherein a control device is provided for determining one or the starting angle (W_Start) and outputs a control signal to a control valve or quick control valve for the at least one support element (18).
  10. Procedure according to Claim 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 or 9 , wherein a control device is provided is which controls the braking elements (8) of the arc brake (7) to decelerate the arcs, in particular according to sensor values, via a servo motor (24).

Description

The invention relates to a method for depositing sheets in a delivery of a sheet-processing machine with a non-stop device. In printing, it is helpful to be able to produce uninterrupted over a longer period. To continue printing even with a full delivery stack, so-called nonstop systems are common. Here, auxiliary stack supports or support elements such as rollers, boards, rods, etc., are inserted into the flow of falling sheets to form a temporary stack, while the pallet change can take place underneath. To allow these support elements to be inserted into the sheet flow without collision, support elements, such as nonstop fingers, with a defined control mechanism are provided at the trailing edge. The system can incorporate one or more nonstop fingers, which are inserted into the arched drop from behind to hold up one arched section upon which the other arched sections then rest. Meanwhile, the stack of arched sections can be lowered until a sufficiently large gap is created into which a roller blind can enter without collision. The problem is that the nonstop fingers, which shoot undefined into the stack area when a nonstop process is triggered, can hit a gap in the arc or the trailing edge of the arc in the arc case. From the DE 10 2005 014 296 A1 A bow trailing edge support is known, wherein at least one separating device is inserted centrally into the stacking area in the bow conveying direction and thereby forms a support area that tapers outwards. The control of the separating elements can be random, time- or angle-controlled, or sensor-controlled. This means that the control of the separating elements is practically arbitrary. The machine angle that can be used is also not disclosed. From the DE 10 2005 058 197 A1 A known arch support structure includes support elements that hold up a trailing edge of an arch while an auxiliary stacking carrier is inserted underneath. The control of the support elements can be random, time-controlled, angle-controlled, or sensor-controlled. This allows for virtually arbitrary control of the separating elements. The specific machine angle that can be used is also not disclosed. From the DE 10 2008 018 315 A1 A device for supporting at least one sheet trailing edge in a delivery of a sheet-processing machine and a method for this purpose are known, wherein, upon a signal from the printer, a specific machine angle is awaited before the delivery stack is lowered. When the delivery stack has reached a certain degree of lowering, the non-stop roller blind is retracted above the delivery stack. Support fingers can be actuated shortly before the non-stop roller blind is retracted, following the signal to change the stack, so that a sheet is supported at the trailing edge before the non-stop roller blind is retracted. From the DE 10 2012 206 929 A1 A method for setting a gripper opening point on a sheet brake is known, wherein brake elements of the sheet brake are driven dynamically and periodically between machine speed and deposit speed. The DE 196 34 910 A1 shows a method for placing sheets onto a stack, whereby the speed of sheets released from grippers in the conveying direction is continuously measured. The invention is based on the objective of creating an alternative method for depositing sheets in the delivery unit of a sheet-processing machine. In particular, it aims to create an improved non-stop operation in the delivery unit of a sheet-processing machine, for example, a printing press. According to the invention, the problem is solved by a method with the features of the independent method claim. Advantageous embodiments are described in the dependent claims, the description, and the drawings. The invention has the advantage of providing an alternative method for depositing sheets into the delivery tray of a sheet-processing machine. In particular, it also enables improved non-stop operation. A suitable sheet-processing machine could, for example, be a printing press, especially an offset rotary printing press, with a delivery tray. This approach offers a particularly advantageous way to trigger the nonstop process at any angle within a clock cycle, whereby the actual start of a nonstop operation, to avoid a collision with a floating bow trailing edge, occurs or is implemented within only a narrow angular interval of a clock cycle. This makes the entire nonstop process reproducible. For temporary intermediate support of the sheet trailing edges during the initiation of a non-stop process, support elements, in particular non-stop fingers, can be provided, which are, for example, part of a pneumatic cylinder piston. The pneumatic cylinder is pneumatically connected to a switching valve, which, when actuated, retracts the support rod or non-stop finger into the stack plan. The electrical control for the switching valve is designed such that the non-stop fingers reach their working position at the machine angle at which the sheet trailing edge is in a predetermined