DE102008054814A1 - Device for detecting position of printing plate on cylinder of printing machine, has register measuring system for detecting position of printing plate in axial and peripheral direction on cover of cylinder by registration marks - Google Patents

Abstract

The device has a register measuring system (11) for detecting the position of a printing plate (4) in axial and peripheral direction on a cover of a cylinder (1) by registration marks (15,16). The registration marks are provided in an area of a printing plate front edge (12), where the register measuring system detects the position of a printing plate rear edge (24) of the printing plate at the cylinder. The register measuring system register has two register measuring elements (20,21).

Description

The The invention relates to a device for detecting the position of a Pressure plate on a cylinder of a printing press with a die Position of the pressure plate in the axial and circumferential direction on the jacket of the cylinder by means provided in the region of a printing plate leading edge Registering registration register system.

In Printing presses it is to increase productivity common practice to work with automatic plate changers. In the plate changing machines are provided for printing Positioned printing plates and after discharging a printed Pressure plate from the pressure plate during the printing process carrying cylinder supplied to this. For clamping and clamping the printing plates on the cylinder's mantle are the printing plate leading edge receiving and fixing clamping unit and a pressure plate trailing edge receiving and fixing and subsequently exciting the printing plate Clamping / clamping unit provided. The clamping unit are spaced from each other arranged arranged dowel pins, with in the pressure plate leading edge Corresponding punched passages correspond. When feeding a pressure plate are the clamping unit and the clamping / clamping unit opened and the pressure plate is punched with the pass created on the dowel pins. After clamping the pressure plate is the cylinder is twisted against the printing direction and the printing plate trailing edge brought to the clamping / clamping unit, wherein means are provided, which approximate the pressure plate to the shell of the cylinder and the Position the free pressure plate trailing edge in the clamping / clamping unit. Thereafter, the clamping / clamping unit is closed and by moving stretched in the circumferential direction, the pressure plate on the cylinder.

adversely is that the concern of the pressure plate with the punch punches on Although the dowel pins signalable, a metrological detection of Position of the trailing edge in the clamping / clamping unit usually is not provided. This can cause the pressure plate trailing edge is not fixed, which when starting the printing machine to machine damage can lead. It is also known, the clamping / clamping unit to provide with the pressure plate trailing edge sensing sensors what to increased costs and to a larger space requirement leads.

at Printing presses are used to produce multicolored print images made for the individual color separations and clamped on designated cylinders of the printing machine. During printing, the drawing files become one after the other transferred from the printing plates on the processed material. For the quality of the processed goods Applied multicolour printing is the accuracy of the overprinting the individual partial images crucial. To create a flawless multicolor print image To obtain, the individual printing plates must respectively applied in an exact predetermined target position on the cylinders be, with the pressure plates both in the axial direction as well in the circumferential direction with an accuracy of about 10 microns be positioned and fixed.

These are, as in the DE 103 452 90 A1 described, associated with each printing plate registration marks. The registration marks may be formed as data codes which contain information about dimensions, orientation, format and / or color of the printing plate, wherein it is also possible to provide position marks in addition to these data codes. Each pass punching is assigned a registration mark, so that when applying the pressure plate on the cylinder, the registration marks are positioned in the immediate vicinity of a dowel pin. The dowel pins are assigned a register measuring system, which usually consists of two register measuring elements which each have a field of view in which a dowel pin and a dowel mark are located.

The Register measuring elements or the register measuring system are exactly in one fixed distance to the cylinder and thus to the on the mantle of the cylinder provided printing plate and in a fixed position target relative arranged to the cylinder. Through the calibrated register measurement / register measurement system and an optionally associated therewith evaluation unit can at a Positioning the pressure plate adjacent to the dowel pins the registration marks and an identification of the printing plate done. If the registration marks lie in a specified desired position, then a quality is more appropriate Pressure possible. Dodges the actual position of the registration marks from the desired position is, by an adjusting movement in the axial and / or circumferential direction, initiates register units assigned to the cylinder, the actual position spent in the desired position. Capturing the distance the pressure plate from the jacket of the cylinder or the pressure plate of The register measuring elements / register measuring system is not provided.

task The invention is the functionality of the generic To expand the device so that a register-correct and trouble-free application a pressure plate on a cylinder is possible.

According to the invention the object by a device according to the features of the claim 1 solved.

With the solution according to the invention it is possible with a register measuring system, which the Position of the printing plate leading edge on dowel pins determined to also check the position of the printing plate trailing edge in an automatic or semi-automatic plate change.

The Invention will be closer to an embodiment explained. In the drawings show:

1 a pressure plate applied to dowel pins in plan view,

2 the pressure plate after 1 in the side view,

3 the representation after 2 with the applied pressure plate on the cylinder and

4 the position of the cylinder in a control position.

In 1 is a cylinder 1 with one at a first dowel pin 2 and a second dowel pin 3 adjacent pressure plate shown in plan view. The cylinder 1 has a cylinder channel 5 in which a plate mounting unit 6 is provided, from which a front clamping unit 7 and a rear clamping / tensioning unit 8th are shown. From the front clamping unit 7 is a terminal block 9 and from the rear clamping / clamping unit 8th a clamping / tensioning tray 10 shown. The terminal block 9 the front clamping unit 7 can be performed in a known manner against an abutment, not shown, or removed therefrom, whereby the pressure plate 4 clamped or released while the clamp / tensioner 10 the rear clamping / clamping unit 8th for clamping against a likewise not shown counter led strip or to release it is removed. In addition, the rear clamping / clamping unit 8th for tensioning the printing plate 4 on a coat 27 of the cylinder 1 in the circumferential direction within the cylinder channel 5 be moved.

In 1 is further shown that a printing plate leading edge 12 the printing plate 4 a first pass hole 13 and a second pass hole 14 assigned. With the first pass hole 13 lies the pressure plate 4 at the first dowel pin 2 and the second fitting hole 14 at the second dowel pin 3 at. But it is z. B. also possible, only a first fitting hole 13 provide and the second dowel pin 3 arrange so that the pressure plate 4 with the printing plate leading edge 12 directly at the second dowel pin 3 is applied. In the immediate vicinity of the first passport 2 are on the printing plate 4 a first pass mark 15 and at the second dowel pin 3 a second pass mark 16 applied. In the exemplary embodiment, the registration marks exist 15 . 16 each from a data code 17 and two position marks 18 , But it is also possible, just a data code 17 to provide and in this the position marks 18 to integrate. The dowel pins 2 . 3 is also a reference position mark 19 assigned.

The first pass mark 14 as well as the first passport 2 lie in the field of view of a first register measuring element 20 and the second registration mark 15 as well as the second dowel pin 3 in the field of view of a second register measuring element 21 when the pressure plate 4 with the passport holes 13 . 14 at the dowel pins 2 . 3 is applied, wherein the register measuring elements 20 . 21 a register measurement system 11 form ( 1 and 2 ). The register measurement elements 20 . 21 are at a fixed distance X to the mantle 27 or to the surface of the cylinder 1 applied pressure plate 4 positioned so that the registration marks 15 . 16 in the focus of the register measurement elements 20 . 21 lie while the reference position marks 19 usually for calibration of the measuring elements 20 . 21 or the register measuring system 11 serve.

When feeding the printing plate 4 to the cylinder 1 this will be with the registration holes 13 . 14 at the dowel pins 2 . 3 applied and the front clamping unit 7 closed by the terminal block 9 is guided against the clamping bearing, not shown. This will be the printing plate 4 in the area of the printing plate leading edge 12 against the coat 27 guided and then the cylinder 1 in the direction of the arrow 28 turned. This will be the position marks 18 / Data codes 17 the registration marks 15 . 16 from the register measurement elements 20 . 21 recorded and compared the actual position with the desired position. In case of deviations of the actual position of the desired position actuating signals are generated and the cylinder 1 assigned actuating units supplied for the realization of travel ranges in the circumferential direction and / or axial direction. After the front clamping unit 7 one to the cylinder 1 assigned plate guide unit 22 in the embodiment as a pressure roller 23 is executed, this is activated and thus to the cylinder 1 employed, so the pressure plate 4 in operative connection with the jacket 27 held until a pressure plate trailing edge 24 into the open rear clamping / clamping unit 8th arrives. After closing and moving the rear clamping / clamping unit 8th in the circumferential direction is the pressure plate 4 on the cylinder 1 curious; excited ( 3 ). This is followed by a reversal of the direction of rotation and the area of the printing plate trailing edge 24 will be at the register measurement elements 20 . 21 , which are additionally activated by a control unit, past and from this the distance to the surface of the printing plate 4 detected as the actual value and compared with the distance X stored as a setpoint value ( 4 ). If the values agree, the printing plate trailing edge became 24 from the rear clamping / clamping unit 8th properly recorded as well as clamped and cocked. Thus, further process steps can be initiated. A not Matching the values signals that the printing plate trailing edge 24 not in the open rear clamping / clamping unit 8th was performed and after their closing z. B. on the clamp / tensioner 10 rests (dashed line in 4 ). In this case, the plate change must be repeated. For detecting the distance of the area of the printing plate trailing edge 24 to the register measuring system 11 it suffices if a register measuring element 20 . 21 is activated while passing the rear clamping / clamping unit 8th after the movement reversal of the cylinder 1 ,

For reliable detection of the position of the area of the printing plate trailing edge 24 in the plate change, it is also possible, as in 1 shown, in this area a first rear registration mark 25 and a second rear registration mark 26 provided. The rear registration marks 25 . 26 can with the in the area of the printing plate leading edge 12 provided pass marks 15 . 16 match and be arranged in mirror image to these. With the rear registration marks 25 . 26 is it possible to change the surface of the printing plate 4 to mark and thus an error-free recognition by the register measuring elements 20 . 21 to realize. It is also possible if the rear registration marks 25 . 26 with the pass marks 15 . 16 match and are arranged in mirror image to that when scanning the passport systems 15 . 16 and the measurements underlying measurements in the circumferential or axial direction must be compared with the values obtained when detecting the rear registration marks 25 . 26 through the register measurement elements 20 . 21 to be generated. If these values agree, the printing plate trailing edge became 24 from the rear clamping / clamping unit 8th captured and the pressure plate 4 Precise on the cylinder 1 applied. If the values do not match, the printing plate trailing edge became 24 not detected and the plate changing process must be repeated.

Become the printing plate trailing edge 24 rear registration marks 25 . 26 is also possible to change the position of the printing plate 4 only one of the rear registration marks 25 . 26 provide and only one of the register measuring elements 20 . 21 to activate.

1

cylinder

2

first dowel

3

second dowel

4

printing plate

5

cylinder gap

6

Plate fixing unit

7

Front terminal unit

8th

Rear Clamping / clamping unit

9

terminal block

10

Clamping / clamping load

11

Register measuring system

12

Printing plate front edge

13

first fitting hole

14

second fitting hole

15

First pass mark

16

Second pass mark

17

data code

18

bookmark

19

Reference position mark

20

first Register measuring element

21

second Register measuring element

22

Plate guide unit

23

pressure roller

24

Printing plate trailing edge

25

First rear registration mark

26

Second rear registration mark

27

coat

28

arrow

X

distance

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 10345290 A1 [0005]

Claims (9)

Device for detecting the position of a printing plate ( 4 ) on a cylinder ( 1 ) of a printing press with a position of the printing plate ( 4 ) in the axial and circumferential direction on the jacket ( 27 ) of the cylinder ( 1 ) by means of in the region of a printing plate leading edge ( 12 ) provided pass marks ( 15 . 16 ) register measuring system ( 11 ), characterized in that the register measuring system ( 11 ) additionally the position of a printing plate trailing edge ( 24 ) of the printing plate ( 4 ) on the cylinder ( 1 ) detected. Device according to claim 1, characterized in that the register measuring system ( 11 ) the distance to the surface of the printing plate ( 4 ) in the area of the printing plate trailing edge ( 24 ) detected. Device according to claim 2, characterized in that the register measuring system ( 11 ) from a first register measuring element ( 20 ) and a second register measuring element ( 21 ) and at least one register measuring element ( 20 . 21 ) for detecting the distance in the region of the printing plate trailing edge ( 24 ) is activated. Apparatus according to claim 2, characterized in that in the region of the printing plate trailing edge ( 24 ) a the detection of the surface of the printing plate ( 4 ) supporting mark is provided. Apparatus according to claim 1, characterized in that in the region of the pressure plate trailing edge ( 24 ) a first rear registration mark ( 25 ) and a second rear registration mark ( 26 ) are provided. Device according to claim 5, characterized in that the rear registration marks ( 25 . 26 ) with the registration marks ( 15 . 16 ) are formed consistently and arranged in mirror image to it. Device according to claim 6, characterized in that in the register measuring system ( 11 ) or an associated evaluation unit a comparison of the from the register measuring system ( 11 ), the position of the printing plate leading edge ( 12 ) characterizing measurements with the by the register measuring system ( 11 ), the position of the printing plate trailing edge ( 24 ) characterizing measured values. Apparatus according to claim 7, characterized in that in a correspondence of the measured values, the pressure plate ( 4 ) on the coat ( 27 ) of the cylinder ( 1 ) is tense. Apparatus according to claim 5, characterized in that in the region of the printing plate trailing edge ( 24 ) at least one rear registration mark ( 25 . 26 ) and the register measuring element ( 20 . 21 ) can be activated in its field of view, the rear registration mark ( 25 . 26 ).