EP2583924B1 - Sheet processing machine with sheet feeder with suction belt module - Google Patents

Description

The invention relates to a sheet processing machine with sheet feeder with Saugbandmodul according to claim 1.

State of the art

A transport device for conveying and simultaneously aligning sheet material is from the DE 34 10 029 known. The slightly slanted against the straightedge conveyor belt is provided with a plurality of openings, which are arranged above a suction opening open to the openings. The sheet-shaped material placed on the conveyor belt is held on the conveyor belt by the generated suction effect and transported to the leveling bar in order to precisely align it for the subsequent further processing steps.

Another generic device is from the DE 44 21 918 known. There it is envisaged that the conveyor belt has on its bow-carrying upper side at least on the straight edge facing the transverse groove open, that the upper run of the conveyor belt runs in an open-topped guide channel whose top is at the same height as the top of the conveyor belt, and the open side of the transverse grooves is in fluid communication with the air intake device.

The DE 10 2004 022 141 A1 describes a device for conveying and simultaneously aligning sheets, with a straightedge and at least one in the sheet running direction slightly obliquely to the directional ruler facing arranged conveyor belt and an air intake, wherein the conveyor belt has open transverse grooves on its top carrying the sheet. The upper run of the conveyor belt runs in an open-top guide channel and the transverse grooves are with the air intake in Flow connection, wherein control means are provided, for controlling the air supply in the region of the transverse grooves.

In the known from the prior art folding machines (eg see DE 10 2008 048 287 ), the speeds of circulating belts of a feed table and first folding rollers or upstream cutter shafts are in a fixed relationship to one another. This is due to a constant mechanical coupling of the respective units with a common drive. In order to achieve a good folding quality of the products, it is important that when transferring the sheet from the alignment table to the first pocket folder or its upstream cutter shafts, the speed of the sheet is equal to the rotational speed of the rotary tools, ie the folding rollers or the upstream cutter shafts. This is achieved according to the prior art so that the running speed of the conveyor belts of the alignment table due to a corresponding gear ratio is always greater than the rotational speed of the rotary tools. In order to match the actual speed of the sheets on the conveyor belts to the rotational speed of the rotary tools, the slip between the sheets and the conveyor belts is varied. The slip is dependent on the frictional force between the conveyor belt and the sheet and results inter alia from the sheet format, the weight of the sheet, the nature of the surface, the normal force on the sheet, etc. To the effective slip and thus the actual Adjusting the speed of the sheet on the conveyor belts usually changes the normal force by varying the number of hold-down balls or, in the case of suction belts, by varying the suction force of the air intake device. These settings require a great deal of experience of the machine operator, as he experiences no support from the machine or the machine control during the adjustment work.

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task

The object of the present invention is therefore to further develop a sheet processing machine with a sheet feeder with suction belt module so that the adaptation of the sheet-actual speed in the area of the sheet feeder is substantially simplified. This object is achieved by a sheet processing machine having the features of claim 1.

The sheet processing machine according to the invention has a sheet feeder with an alignment table and further at least one processing station, wherein the sheet feeder is used for separating sheets. Singling means that the sheets are unstacked in order to be able to be transported at a distance or in a scale flow. The alignment table has at least one Saugbandmodul with at least one circulating suction belt for transporting the sheet at a bow-actual speed. The processing station has at least one rotary tool for processing the sheets. If the sheet processing machine is a sheet folding machine, the rotary tools are preferably designed as folding rollers or upstream cutter shafts.

According to the invention, the alignment table has a first measuring device for determining the sheet-actual speed (or in alternative notation: actual arc speed) and the processing station a second measuring device for determining the circumferential or rotational speed of the at least one rotary tool. If the rotational speed or a rotational speed is determined by the second measuring device, then the peripheral speed of the rotary tool is calculated on its effective surface. Both the first measuring device and the second measuring device and the suction belt module are connected to a computer, which comprises an evaluation unit and the machine control. It is advantageous that here the actual sheet speed, the actual sheet speed is measured and not the known speed of the suction belt is used. Due to slippage between the suction belt and the bow, their speeds differ. According to the invention, a more precise speed control is thus made possible.

According to a first variant of the sheet processing machine according to the invention, the result of the speed measurements is shown: the sheet processing machine has for this purpose connected to the control computer display / display either for Display of actual bow speed and circumferential or rotational speed or to display the difference between actual bow speed and circumferential or rotational speed. Based on this display, the machine operator can vary the actual bow speed by means of an operating element of the sheet processing machine in such a way that the speed difference is corrected, for example by varying the suction force of the suction belt module.

Advantageously, according to a second variant of the invention, the suction belt module is controlled by the computer such that the actual arc speed and the peripheral speed of the at least one rotary tool are approximately equal. This is achieved by changing the suction force of the suction belt module and thus the effective slip between the suction belt and a respective sheet. For this purpose, the computer has a program for adjusting the speed and the suction power of the suction belt can be changed. Such a sheet processing machine has the advantage that the adjustment of the sheet speed can be performed automatically without adding to the machine operator. If the running speed of the sheet processing machine changes, the suction force of the suction belt module is automatically readjusted. The control loop comprises the activation of the suction belt module (control computer) and the two measuring devices.

In an advantageous embodiment of the sheet processing machine according to the invention, the second measuring device is designed as a rotary encoder and the first measuring device is arranged only in the outlet region of the alignment table. Outlet area of the alignment table means the downstream area of the alignment table, so that the actual speed of a sheet can be measured just before the sheet is transferred from the alignment table to the processing station. The actual sheet speed is therefore determined in the outlet region of the alignment table, since the speed changes only insignificantly until the transfer to the rotary tool.

In a particularly advantageous and therefore preferred embodiment, the first measuring device has at least one optical sensor. This is suitable, the actual arc speed capture. In one embodiment, the first measuring device has two sensors, which are arranged on an axis parallel to the transport direction at a distance of 200 to 300 mm, in particular of about 250 mm to each other. The sensors have the ability to detect the passage of sheet edges. Due to the time span between the detection of a sheet edge by the upstream sensor and the downstream sensor and the known distance between the two sensors, the actual sheet speed can be determined directly.

In an advantageous development of the sheet-processing machine, the latter has a data memory for order-related storage of operating parameters of the suction belt, wherein in particular the effective suction force or the activation parameters can be stored to achieve a required suction force. The values stored in the data memory can be retrieved for repeat jobs, so that the last empirical values are taken into account at startup.

In order to ensure a simple construction of the sheet processing machine, the alignment table and the processing unit each have a drive unit, which is in each case mechanically coupled to a main drive of the sheet processing machine.

The described invention and the described advantageous developments of the invention are also in any combination with each other advantageous developments of the invention.

With regard to further advantages and advantageous embodiments of the invention, reference is made to the dependent claims and the description of an embodiment with reference to the accompanying drawings.

embodiment

Fig. 1a und b

eine Bogenfalzmaschine gemäß dem Stand der Technik

Fig. 2a

eine Ansicht einer erfindungsgemäßen Falzmaschine

Fig. 2b

eine Draufsicht auf die erfindungsgemäße Falzmaschine von Fig. 2a

The invention will be explained in more detail with reference to an embodiment. It show in a schematic representation

Fig. 1a and b

a sheet folding machine according to the prior art

Fig. 2a

a view of a folding machine according to the invention

Fig. 2b

a plan view of the folding machine according to the invention of Fig. 2a

The FIGS. 1a and 1b show a folding machine 100, as known from the prior art. The folding machine 100 has a sheet feeder 1, an alignment table 2, a processing station 3 and a machine control with computer 4. The sheet feeder 1 causes a separation of sheet B from a sheet pile S, including a separating sucker 11 (Tremat) at the trailing edge of the stack S by means of blowing air and lifting sucker a sheet B from the stack separates and lifts, which then by a suction 10 to the alignment table. 2 can be handed over. The alignment table 2 has a plurality of guide rails 23 on which a respective sheet B rests during its transport in the sheet transport direction T. During transport via the alignment table 2, a respective sheet B is transported by the conveyor belt 20, which is slightly oblique to the sheet transport direction T, against an alignment ruler 21 and aligned. In order to prevent lifting of a respective sheet B and to ensure that a respective sheet B remains in contact with the conveyor belt 20, a plurality of hold-down balls 22 are provided. An aligned sheet B is subsequently transferred to the processing station 3, shown here as the first folding station. The folding station 3 has upstream cutter shafts 30, first folding rollers 31, second folding rollers 32 and folding pockets 33. In the illustration of FIGS. 1a and 1b If the folding station 3 does not have any upstream cutter shafts 30, the first rotary tool of the processing station 3 is formed by the folding rollers 31.

In the FIGS. 2a and 2 B an inventive sheet processing machine is shown, which is designed here as a folding machine. The folding machine 100 also includes a sheet feeder 1, an alignment table 2, a processing station 3 - designed as a first folding station - and a machine control with computer 4. The separated by the sheet feeder 1 of a sheet stack S sheet B are via an alignment table 2 of the folding station. 3 fed. The alignment table 2 has a Saugbandmodul 24, which includes a vacuum pump 25 and a suction belt 20. A respective sheet B is sucked during its transport in the sheet transport direction T by the suction belt 20 and thus moved against an alignment ruler 21 and aligned therewith. In the outlet region of the alignment table 2, two sensors 51 and 52 are arranged, which together form the first measuring device 50. The downstream sensor 52 is arranged at a distance from the upstream sensor 51, wherein the distance d is. The sensors 51 and 52 are connected to the machine control 4, which controls the feeder 1, the alignment table 2 and the processing station 3. By the first measuring device 50, the actual speed v of each sheet B is determined in the outlet region of the alignment table. A second measuring device 60 is provided in the processing station 3 and serves to determine the peripheral speed of the first rotary tool 30 or 31. The second measuring device 60 is also linked to the machine control 4. If the peripheral speed on the active element of a respective rotary tool 30 or 31 is not directly measured by the second measuring device 60, then this is calculated by the machine control 4 based on the measured rotational speed ω or the rotational speed. In the machine control 4, a comparison is then made of the measured actual speed v and the peripheral speed ω. If the two velocities v, ω do not match, the actual sheet speed v is changed by the machine control by adjusting the effective normal force to an arc B in the region of the suction belt 20. In other words, by adjusting the suction force of the suction belt module 24, the slip between the suction belt 20 and the sheet B is adjusted. If there is too little actual arc speed v, the suction force is increased, if too high actual arc speed v is present, the suction force is reduced. If the running speed of the sheet folding machine 100 is changed, the sheet actual velocity v is automatically adapted to the changed rotation speed ω of the rotary tools 30, 31. The parameters for controlling the suction belt module 24 can be stored in a data memory 40 of the machine control 4.

LIST OF REFERENCE NUMBERS

1

sheet feeder

2

alignment table

3

processing station

4

Machine control with computer

10

suction wheel

11

Vacuum cleaner (Tremat)

12

vacuum pump

13

compressor

14

page blowers

20

conveyor belt

21

aligning gauge

22

Hold balls

23

guide rails

24

Saugbandmodul

25

vacuum pump

30

Rotary tool (upstream cutter shafts)

31

Rotary tool (folding rollers)

32

folding rollers

33

folding pocket

40

data storage

50

1st measuring device

51

upstream sensor

52

downstream sensor

60

2. Measuring device / rotary encoder

100

Sheet processing machine (folding machine)

B

single sheet

S

sheet pile

T

transport direction

d

distance

v

bow speed

ω

Rotational speed / peripheral speed

Claims (10)

1. Machine (100) for processing sheets comprising a sheet feeder (1), an alignment table (2) and at least one processing station (3), wherein the sheet feeder (1) is used to separate sheets (B), wherein the alignment table (2) has a suction belt module (24) having at least one revolving suction belt (20) for transporting the sheets (B) at an actual sheet speed (v), and wherein the processing station (3) has at least one rotary tool (31, 32) for processing the sheets (B),
   characterized in
   that the alignment table (2) includes a first measuring device (50) for determining the actual sheet speed (v) and the processing station (3) includes a second measuring device (60) for measuring the circumferential and/or rotary speed (ω) of the at least one rotary tool (31, 32) and that the at least first and second measuring device (50, 60) and the suction belt module (24) are connected to a control unit (4).
2. Machine for processing sheets according to claim 1,
   characterized in
   that the machine (100) for processing sheets has a display device connected to the control unit (4) to display the actual sheet speed (v) and the circumferential and/or rotary speed (ω) or to display the difference between the actual speed (v) and the circumferential and/or rotary speed (ω)and that the machine (100) for processing sheets has an operating element for varying the actual sheet speed (v).
3. Machine for processing sheets according to claim 1,
   characterized in
   that the suction belt module (24) is controlled by the control unit (4) in such a way that the actual sheet speed (v) and the circumferential speed (ω) of the at least one rotary tool (30, 31) are approximately equal.
4. Machine for processing sheets according to claim 3,
   characterized in
   that the suction force of the suction belt module (24) is modified, modifying the slip between the suction belt (20) and a respective sheet (B).
5. Machine for processing sheets according to any one of the preceding claims,
   characterized in
   that the first measuring device (50) is disposed in the exit region of the alignment table (2) and/or that the second measuring device (60) is embodied as a rotary encoder.
6. Machine for processing sheets according to any one of the preceding claims,
   characterized in
   that the first measuring device (50) includes at least one optical sensor (51, 52).
7. Machine for processing sheets according to any one of the preceding claims,
   
   characterized in
   that the first measuring device (50) has two sensors (51, 52) that are disposed on an axis parallel to the direction of transport (T) and at a distance (d) of 200 to 300 mm, in particular of 250 mm, from each other.
8. Machine for processing sheets according to any one of the preceding claims, characterized in
   that the machine (100) for processing sheets has a data memory (40) for saving operating parameters of the suction module (24), in particular the suction force, in a job-related way.
9. Machine for processing sheets according to any one of the preceding claims,
   characterized in
   that the alignment table (2) and the processing unit (3) are provided with a respective drive unit that is mechanically coupled to a main drive of the machine (100) for processing sheets.
10. Machine for processing sheets according to any one of the preceding claims,
    characterized in
    that the machine (100) for processing sheets is a sheet folding machine and/or that the at least one rotary tool consists of folding rollers (31) or upstream knife shafts (30).

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