WO1993003990A1

WO1993003990A1 - Device for regulating and/or controlling individual setting elements in the sheet delivery region of a printing machine

Info

Publication number: WO1993003990A1
Application number: PCT/EP1992/001641
Authority: WO
Inventors: Peter Theobald Blaser; Dieter Hauck; Karl-Hermann Miltner; Anton Rodi
Original assignee: Heidelberger Druckmaschinen Ag
Priority date: 1991-08-16
Filing date: 1992-07-18
Publication date: 1993-03-04
Also published as: EP0553321A1; JP3210015B2; EP0553321B1; ATE123471T1; CA2093360A1; CA2093360C; DE59202456D1; JPH06504023A; EP0553321B2

Abstract

A special eye must be kept on the laying of the sheet on the delivery stack, especially in the range of high machine speeds. The purpose of the present invention is to propose a device for controlling and/or regulating the setting elements in the sheet delivery region of a sheet printing machine. The settings of the setting elements of the sheet delivery are calculated with reference to characteristics specific to the paper and printing machine in such a way that the sheet being placed on top of the sheet stack is virtually stationary.

Description

Device for regulating and / or controlling individual control elements 1m from a printing press

The invention relates to a device for regulating and / or controlling individual control elements in the area of the delivery of a sheet-fed printing press, wherein at least one input device for entering sheet-specific and / or printing press-specific characteristic data and at least one computing device for further use of the characteristic data are provided and wherein a control device is also provided _/ which causes a format-dependent setting in accordance with the specified characteristic data for individual position elements.

From DE 34 13 179 A1 a control and regulation device for the sheet feeder of a sheet-fed printing press has already become known. The sheet format, the paper weight and the speed of the machine are entered into a computing device via at least one input device. Format-dependent settings are made according to the input data. In addition, for example, the gripper opening curve is set or the suction roller is set according to setpoints _/ which have been empirically determined for each operating state and are stored in the form of characteristic fields in a storage element.

A disadvantage of this invention can certainly be regarded as _/ that the empirical determinations of the respective setting data depending on the sizes of paper weight and speed are very lengthy. In addition, these characteristic curves must be determined by a qualified specialist. The storage of the key data fields still requires a high storage capacity. Problems are also likely to result from _/ that the characteristic fields contain no continuous curves. Rather, the measurements are carried out with some fixed parameter combinations; the measured values are then interpolated. In addition, it is provided in DE 34 13 179 A1 _/ that for the optimization of the sheet delivery by the printer individual setting values can be corrected _/ th to what Unstetigkei resulting in the characteristic curves.

Based on this prior art, the present invention is based on the object _/ to propose a device for controlling and / or regulating the control elements in the sheet delivery section of a sheet-fed printing press _/ which uses paper-specific and printing-machine-specific characteristic data to set the setting values of the set elements of the sheet Legers determined.

This object is achieved _/ that the computing device calculates the energy of the sheet arriving in the delivery from the characteristic data _/ that the computing device furthermore, according to the calculated energy values, the control variables for the suction roll and / or the gripper opening curve and / or the blowing nozzles via the delivery stack in such a way determines _/ that the energy extraction caused by these elements corresponds essentially to the energy of the sheet arriving at the legeberei ch and that the control device controls the suction roller and / or the gripper opening curve and / or the blowing nozzles via the position stack l in accordance with the calculated values.

According to an advantageous embodiment of the method according to the invention, the computing device calculates the suction force of the suction roll according to the formula

m * v ^:

F =

2 * μ * s wherein the weight of the sheet v, the velocity of the incoming sheet in the delivery _/ μ a friction value and s _/ represents the paper length _/ on which acts the suction force of the suction roll. With a constant paper length s over which the suction force of the suction roller acts _/ ie with a fixed setting of the gripper opening curve _/ the suction force F of the suction roller changes as a function of the square of the speed of the sheet arriving in the sheet delivery.

According to a further development of the invention

Procedure is provided _/ that when the maximum is reached

Suction force F the control device varies the gripper opening curve max in such a way _/ that the length of paper _/ over which the suction force of the suction roller acts _/ according to the formula

m * v ² s =

2 * μ * F max

will be changed.

According to an alternative embodiment of the device according to the invention it is provided _/ that the computing device as a function of the energy _/ with which the sheet arrives in the delivery _/ the paper length s over which the suction force of the suction roller acts _/ according to the formula

m * v ² s =

2 * μ * F

calculated. When the setting limit of the maximum possible paper length s _/ over which the suction force of the max suction roller acts _{/ is} calculated, the computing device calculates the

Suction power of the suction roller according to the formula

m * v ²

F =

2 * μ * s max Typically, the procedure will be such _/ that the suction force according to the aforementioned formula

m * v

F =

2 * μ * s

is calculated, s is initially kept constant. When setting s it is taken into account _/ that the sheet arrives the better the deposit _/ the longer it is passed through the gripper, ie ₇ the shorter s. Only in exceptional cases will the sheet delivery be corrected by changing the paper length s over which the suction force of the suction roller acts _{/ is} carried out.

In a further development of the device according to the invention it is proposed _/ that input devices are provided _/ which supply the computing device with information about the respective dye _/ lacquer, dampening solution and / or powder application on the sheet _/ and that the computing device has this increase in mass when calculating the energy of the sheet arriving in the delivery. For example, information about the amount of ink applied to the sheet can be obtained via the position of the ink slides. The paint _/ dampening agent and / or powder application on the sheet can also be easily determined.

Alternatively or additionally, an input device is provided _/ via which the printer influences the suction force F of the suction roller or the paper length s_ via which the suction force of the suction roller acts _/ by means of a correction factor k. For example, if in the original calculation program of the mass increase is not considered by the dyes _/ paints _/ Feuchtmi ttel- or powder application _/ so the printer is thereby given the opportunity by correcting the Suction power of the suction roller or by correcting the

Gripper opening curve to act on the deposit of the sheet.

In a development is proposed _/ that one of the

Correction factor k entered when calculating the

Suction force F of the suction roller or when calculating the

Paper sheet length s is taken into account and that when the setting limit of the suction force F is reached or when the maximum maximum paper length s is reached, the specified correction factor for the max calculation of the paper length s or for the calculation of the

Suction power F is taken over. The use of a

Correction factor offers the advantage _/ that corrections take effect over the entire speed range _/ whereby there are no discontinuities in the setting values of the setting elements.

It is advantageous in this case _/ if the found correction factor k, which is ok SETTINGS lungs effected in dependence on the predetermined parameters _/ taken at the end of print job in the memory of the computing device. The stored value is then automatically adopted as a default for a follow-up order with the same parameters _/ so that a new correction of the settings of the suction roller or the gripper opening curve is not or only slightly necessary.

In a further embodiment of the inventive method _/ that the control device controls the device in such a powder _/ that the applied depending on the engine speed per unit area quantity of powder is constant. It is further provided _/ that the computing device calculates the load applied to a bow amount of powder depending on the Endstapelhöhe. For example, the amount of powder applied to the sheet can decrease linearly from the bottom edge of the stack to the top edge of the stack. Because the pressure on the lower sheet is significantly higher than on the upper one _/ this prevents the sheets from sticking together in the lower region of the stack.

According to one embodiment of the device according to the invention, it is proposed _/ that the control device can be supplied with data about the mass distribution of a printed sheet via the input device and that the control device controls the blower nozzles _/ that a pressure distribution is generated over the surface of the sheet _/ which with the mass distribution of the Arc correlates.

Since the blowing nozzles are controlled by the control device in such a way _/ that the pressure distribution corresponds to the real areal mass distribution of the sheet _/ the sheet can be deposited on the stack precisely and quickly. Under certain circumstances it may be advantageous _/ tuyeres that due to the pressure distribution of the arc is first placed in the center of the arc so set _/. However, the tray can also be carried out _/ that starting _/ which eccentrically _/ quickly find their way from the first stored location typically If the air under the bow outward. The B las air nozzles acting on the sheet from above can possibly be supported by suction devices arranged on the side of the stack.

The areal mass distribution can use the rect Rechenvorri be accurately determined _/ when this _/ are supplied to the inking _/ Pudei- and / or lacquer application the data on the Papierdickβ. For example, the information about the color distribution can be determined via the position of the ink fountain keys. It is also advantageous _/ if the surface of the sheet is divided into matrix-like F surface elements to determine the mass distribution and for these surface elements the mass of the color _/ lacquer, dampening solution and powder minus the evaporation or powder loss is determined in addition to the paper weight becomes. Devices for measuring the weight of the stack before printing and after printing can be installed as auxiliary devices. The setting of a pressure distribution corresponding to the mass distribution by means of the blowing nozzles can be carried out in a variety of ways, depending on the design. So it is possible _/ to vary the amount of blown air, the number of activated blowing nozzles and the direction of the blowing action depending on the known sheet and machine-specific data.

It is structurally advantageous if a blown air device is provided above the stack, which has air outlet nozzles distributed in matrix form over the surface of a sheet _/ wherein the nozzles are individually supplied with blown air by means of the control device. It is therefore possible _/ at the nozzles _/ which act on an area of the sheet _/ which is to be deposited first _/ to let blow air escape earlier than with the remaining nozzles. For example, the nozzles are switched off in rows starting from the rear edge in the direction of the front edge.

The invention is illustrated by the following drawings.

It shows:

Fig. 1 is a schematic side view of the legeberei chs a sheet-fed rotary printing press and Fig. 2 is a sketched representation of the quantities calculable by means of the method according to the invention.

In Fig. 1, a sheet delivery 1 is a not shown in a schematic side view

Sheet-fed rotary printing machine shown. The chains 2 with the

Gripper bars 3 run over the U steering wheels 4 _/ 5. The Gripper bridges convey the sheets 6 in the direction of the delivery stack 7. The sheets are braked by the suction roller 9 as soon as the sheet 6 is released by the gripper bridges 3 above the delivery stack 7. The Grei bridge 3 are controlled via the Grei opening curve 10. The sheet 6 is pressed down on the delivery stack 7 by means of the blowing nozzles 11.

The tray of the sheet 6 on the delivery stack 7 should take place _/ the braking force F of the suction roll 9 and the effective braking distance s are dimensioned so _/ that upon reaching the trailing edge of the delivery pile 7, the kinetic energy of the sheet 6 is at least very small, ideally in this way. This prevents _/ that the sheet hits the stacking stops 8 too hard _/ which would damage the sheet 6.

According to the invention the setting of the suction roll and / or the Grei feröffnungskurve is controlled so _/ that this condition is always met.

The sizes _/ which are used to calculate the setting of the suction roll 9 or to set the gripper opening curve _/ are shown schematically in FIG. 2.

2 essentially represents the area around the suction roller 9 according to FIG. 1. The sheet 6 is guided by the gripper bridge 3 over the suction roller 9. The suction roller 9 is connected to a vacuum source, not shown in the drawing. The suction force F of the suction roller 9 is adjustable. As long as the sheet 6 is guided by the gripper bridges 3, it moves at machine speed. If the sheet 6 is released from the gripper bridge 3 _/ due to the suction force F of the suction roller 9, the sheet 6 is braked. S denotes the paper length of the sheet 6, over which the suction force F of the suction roller 9 acts. Under Taking into account the coefficient of friction μ, the energy _/ which is applied by the suction roller 9 for braking the sheet 6 and thus for extracting the energy from the sheet 6 _/ according to the formula

E = F * μ * s

to calculate. Ideally, this removal of the energy from the sheet is equal to the kinetic energy 1/2 * m * v ² of the sheet 6 arriving in the outfeed area of a sheet-fed rotary printing press.

As already mentioned _/ characterizes the size s the paper length of the sheet 6 _/ over which the suction force F of the suction roller 9 acts _/ after the sheet 6 is no longer guided by the gripper bridge 3. Please note _/ that the suction roller itself may also turn. Only in the case _/ that the suction roller stands _/ marks the paper length of the sheet 6 behind the suction roller 9. If the suction roller 9 rotates in the direction of paper movement or against the direction of the paper movement _/ then the circumferential distance of the suction roller 9 from the time of opening of the Gripper bridges 3 until the time _/ at which the sheet 6 has passed the suction roller 9 _{/ are} taken into account. By this circumferential distance, the paper length s of the sheet 6 behind the suction roller 9 must be reduced when rotating in the direction of the paper and increased when rotating against the direction of the paper.

In general, it can be said _/ that the sheet 6 is deposited the better _/ the longer the sheet 6 is guided through the gripper bridges 3 _/ ie _/ the shorter the paper length s over which the suction force F of the suction roller 9 acts. The cheapest procedure for calculating the settings of the control elements in the layer range will therefore be _/ that the setting of the gripping opening curve 10 is initially constant. The suction force F of the suction roller 9 can then be according to the formula m * v

F =

2 * μ * s

depending on the square of the speed of the sheet 6 arriving at the printing press. The data required for the calculation _/ such as the mass of the sheet or its length _/ width _/ thickness and density _/ as well as the speed information are fed to a computer 13 via an input device 12. This input is made either by the operating personnel or via appropriate measuring points on the printing press itself. For example, the paper thickness can be determined using the pressure input and the declaring height adjustment. Format-dependent information can be obtained on the basis of the drawing mark position or by means of the ink zone element. The speed of the sheet 6 arriving at legeberei chs is easily determined from the speed of rotation of the printing press. Information about the ink application in the individual printing units _/ which may be taken into account for the correction of the mass m of the sheet 6 _/ can be determined from the position of the ink zone scraps. Similarly, the computer can also be provided with the amount of lacquer, dampening solution or powder applied to the sheet.

Is according to the formula

m *

F =

2 * μ * s

where s is constant, the actuating force F of the suction roller 9 reaches _/ so the computer calculates the necessary correction when setting the gripper opening curve 10 via the form l m * v ² s =

2 * μ * F ma x

If it for some reason occur _/ that beispiels¬, the calculated suction force F of the suction roll 9 feröffnungskurve at a fixed setting of the Grei 10 does not lead _/ so the Bedienperso¬ is given nal via the input device 12, the possibility of an optimum delivery of the sheet 6 _/ the Influence suction force F of the suction roller 9 via a correction factor k. If the setting limit of the suction force F of the suction roller 9 is reached _/ max when the speed v is increased, the computer 13 also takes this correction factor into account when calculating the paper length s. Of course, s can also be influenced directly by the correction factor k.

Is low with this procedure _/ that the correction is effective over the entire speed range, and thus no discontinuities in the adjustment of the suction force or the paper length s, over which the suction force F acts _/ leads.

Provision is also made _/ taken that are the correction factors in dependence on the inputted parameters in a memory device. These corrections are automatically taken into account in subsequent orders with the same parameters for setting the suction force F of the suction roller 9 or for setting the gripper opening curve 10.

Claims

PATENT CLAIMS

Means for regulating and / or controlling individual setting elements in the region of delivery of a sheet printing press _/ wherein at least one input device for inputting sheet and / or printing press-specific characteristic data and at least one computing device are provided for any further use of the characteristic data, and further wherein a control device is provided _/ the at individual adjusting elements, a format-dependent adjustment caused in accordance with the characteristic data input _/ characterized in _/ that the computing means (13) from the characteristic data the energy of the incoming to the display sheet (6) is calculated _/ the computing device (13) further in accordance with the calculated energy values, the control variables for the Suction roller (9) and / or the Grei feröffnungskurve (10) and / or the blow nozzles (11) on the delivery stack (7) determined _/ that the energy extraction caused by these elements essentially the energy of the arriving in the legeberei ch ogens (6) and that the control device (14) controls the suction roller (9) and / or the gripper opening curve (10) and / or the blowing nozzles (11) above the delivery stack (7) in accordance with the calculated values. 2. Device according to claim 1 _/ characterized in _/ that the computing device (14), the suction force (F)

Suction roller (9) according to the formula

m * v

F =

2 * μ * s

calcd _/ where m is the mass of the sheet (6) _/ v is the velocity of in the delivery incoming sheet (6) _/ μ a friction value and s is the length of paper _/ over which the suction force (F) _/ represents the suction roll (9) acts.

3. Device according to claim 2, characterized in _/ that input devices (12) are provided _/ that of

Computing device (13) information about the respective

Dye _/ lacquer _/ dampening solution and / or powder application on the

Feed sheet and that the computing device (13) this increase in mass when calculating the energy of the arriving in the delivery

Arc (6) is taken into account.

Device according to claim 2 or 3 _/ characterized in _/ that when the maximum suction force (F) of the suction roll max (9), the computing device (13)

Length of paper (s) over which the suction force (F) of the

Suction roller (9) acts _/ according to the formula

m * v ^« s =

2 * μ * F max calculated. Device according to claim 1 or 3 _/ characterized in _/ that the computing means (13) depending on the

Energy with which the sheet (6) arrives in the delivery _/ the paper length (s) _/ over which the suction power (F) of the

Suction roller (9) acts _/ according to the formula

m * v s =

2 * μ * F

calculated and that the control device (14) the

Gripper opening curve (10) according to the calculated

Driven values.

6. Device according to claim 5, characterized _/ that when reaching the maximum possible

Paper length (s) the computing device (13) the maximum suction force (F) of the suction roller (9) according to the formula

m * v

F =

2 * μ * s max calculated and that the control device (14) controls the suction roller (9) according to the calculated values.

7. Device according to one or more of the preceding claims _/ characterized in _/ that an input device (12) is provided _/ via which the printer the suction force (F) of the suction roller (9) or the paper length (s) _/ via which the suction force (F) the suction roller (9) acts _{/ influenced} by a correction factor k. 8. Device according to claim 4 and / or 6, characterized in _/ that an input device (12) is provided _/ via which the printer can enter a correction factor k _/ that the computing device (13) this correction factor (k) in the calculation of the suction force (F ) of the suction roller (9) or in the paper sheet length (s) and that when the setting limit of the suction force (F) max is reached or when the maximum paper sheet length (s) max is reached the correction factor (k) for calculating the

Length of paper (s) over which the suction force (F) of the

Suction roller (9) acts _/ or to calculate the

Suction power (F) is taken over.

9. A device according to claim 7 or 8 _/ characterized in _/ that are transferred during printing job end of the correction factors (k) in the memory of the computing device (13).

10. Device according to claim 1 _/ characterized in _/ that the control device (14) controls the powder device in such a way _/ that the amount of powder applied per area is constant depending on the machine speed.

11. The device according to claim 10 characterized _{/ in} that the computing device (13) calculates the amount of powder as a function of the final stack height. 12. The device according to claim 1, characterized _{/ in} that the control device (14) on the

Input device (12) data about the mass distribution of a printed sheet (6) can be supplied and that the control device (14) controls the blowing nozzles _/ that a pressure distribution is generated over the surface of the sheet (6) _/ which is related to the mass distribution of the sheet ( 6) correlated.