CN106166894B

CN106166894B - Plate changer

Info

Publication number: CN106166894B
Application number: CN201610341890.1A
Authority: CN
Inventors: S·巴莱斯; M·祖贝尔; D·舍恩曼; M·格赖弗; G·斯特凡; B·西茨曼
Original assignee: Heidelberger Druckmaschinen AG
Current assignee: Heidelberger Druckmaschinen AG
Priority date: 2015-05-22
Filing date: 2016-05-20
Publication date: 2020-09-01
Anticipated expiration: 2036-05-20
Also published as: DE102016206223A1; CN106166894A

Abstract

The invention relates to a plate changer for a printing press, comprising a clamping device having a first clamping surface (19) and a second clamping surface (20) which are end in the transport direction of a printing plate, wherein the printing plate can be clamped between the first clamping surface (19) and the second clamping surface (20).

Description

Plate changer

Technical Field

The invention relates to a plate changer for a printing press.

Background

EP 0603245B 1 describes a plate changer comprising a carriage for transporting a printing plate. The carriage has a holding device for holding the printing plate, which is designed as a suction element. The plate changer is not suitable for changing flexographic plates. In contrast to flat offset printing plates, flexographic printing plates have a surface relief (flexographic relief) with a defined print image. When the suction member is placed on the relief plate, an airtight connection between the suction member and the printing plate cannot be achieved and erroneous air suction cannot be avoided due to unevenness of the relief plate. It is believed that the false air is in most cases so large that the printing plate cannot be held with the suction member in practice.

DE 102012014806 a1 describes a plate changer having a fixed transport roller arranged on the housing of the plate changer and a pivotable transport roller arranged at the end of a lever. When the printing plate is transported away from the plate cylinder, the pivotable transport roller bears against the fixed transport roller and the printing plate is clamped between the two rotating transport rollers. The circumferential surface of the conveyor roller is endlessly long in accordance with the roller properties and forms a rotating clamping surface. That is, there are two rotating endless clamping surfaces between which the printing plate is clamped. The plate changer is also not suitable for changing flexographic plates. The surface relief of flexographic plates usually has very fine projections or tips so that fine picture elements, such as dots, can be printed. There is a risk of the tip of the flexographic plate being worn by the slipping of the roller. The plate may become unusable due to such damage.

Disclosure of Invention

The object of the invention is to provide a plate changer which is well suited for flexographic plates.

This object is achieved by a plate changer for a printing press, comprising a clamping device having a first clamping surface and a second clamping surface which are terminated in the transport direction of the printing plates, wherein the printing plates can be clamped between the first clamping surface and the second clamping surface.

In the case of the plate changer according to the invention, there is neither the problem of false air suction nor the problem of relief wear. The plate changer is preferably suitable for printing plates with sensitive surface relief, for example flexographic printing plates, which are used as varnishing plates for spot varnishing in varnishing (varnish) units or in flexographic printing units. The plate changer according to the invention is preferably a component of a varnishing unit or a flexographic printing unit. An additional advantage is that the clamping device of the plate changer according to the invention is also suitable for flat offset printing plates, so that the plate changer can also be used as a component of an offset printing unit. Thus, a plate changer of the same design can be used for offset printing units and for varnishing units (flexographic printing units), as a result of which the production costs can be reduced.

Different further variants of the plate changer according to the invention are possible.

In a further development, the clamping device is a component of a transport slide, which can be moved in the transport direction. The clamping device forms a holding device by means of which the transport slide grips the printing plate, while the transport slide transports the printing plate in the transport direction to the plate cylinder. The clamping device is preferably arranged inside the transport slide such that the gripping point (clamping point) of the clamping device is in a section of the printing plate which is the first quarter of the printing plate in the transport direction during transport of the printing plate to the plate cylinder.

In a further development, the clamping device comprises a clamping post on which the first clamping surface is formed. The clamping column is mounted so as to be linearly displaceable in an adjustment direction, which is perpendicular to the transport direction and the transport plane of the printing plate. The clamping cylinder is brought into a clamping position, in which the printing plate is clamped between the first clamping surface and the second clamping surface, by moving the clamping cylinder in the adjustment direction. The clamping post can be moved into the clamping position by a spring during clamping and moved back from the clamping position by an actuator during unclamping, the latter being effected against the action of the spring. The actuator is a working cylinder, preferably a pneumatic cylinder. The second clamping surface can be formed on a flat clamping support, which is arranged aligned with the clamping post in the adjustment direction of the clamping post. The second clamping surface formed on the flat clamping support, like the first clamping surface, is a terminal clamping surface, i.e. not the circumferential surface of the roller.

In a further development, the plate changer has an actuator or a motor, for example an electric motor, and a transmission. The motor drives the transport carriage via a transmission in order to move the transport carriage in the transport direction and back again. The transmission may be a belt transmission, for example a wedge belt transmission, or a transmission having a toothed transmission member, for example a gear transmission or a rack transmission. The transmission is preferably a toothed belt transmission and thus not only a belt transmission but also a transmission having toothed transmission members. The toothed belt transmission includes a toothed belt as a transmission member provided with teeth and a pulley provided with teeth.

Drawings

Further developments also result from the description of the embodiments and the drawings, in which:

figure 1 shows a printing press in which the printing press is shown,

figure 2 shows a varnishing unit of a printing press,

fig. 3 shows the plate cylinder and the plate changer of the varnishing unit, with the plate guides of the plate changer,

figure 4a shows the plate guide from the viewing direction BR (see figure 3),

figure 4b shows a variant of the plate guide,

fig. 5 shows a transport slide of a printing plate guide, with a clamping device of the transport slide,

figure 6 shows a detail of the clamping device of the transport slide,

figure 7 shows a drive arrangement for driving the slide,

figure 8 shows a register for printing plates on a plate changer and a register on a plate cylinder,

FIGS. 9a to 9d show the sequence of adjusting the printing plates with respect to the register device of the plate changer by means of the transport slide, and

fig. 10 shows a multifunctional element with guiding and protecting functions.

Detailed Description

Fig. 1 shows a printing press 1 with an offset printing unit and a flexographic printing unit as a varnishing unit 48. The printing press is a sheet printing press with a feeder and a collector, not shown.

Fig. 2 shows that the varnishing unit 48 has a plate cylinder 2 and a plate changer 5 for changing printing plates 4. The printing plate 4 is a flexible printing plate for spot painting. In a printing operation, a roller 42, which is a coating roller and also a screen roller, rolls over the printing plate 4.

Fig. 3 shows that the plate changer 5 has a plate guide 14 and a plate well 5, which extends vertically. The plate guide 14 is supported in the joint 13 and can be pivoted outwards. The transport carriage 6 is mounted movably in the plate guide 14. The printing plate guide 14 is pivoted about the joint 13 in order to be adjusted into a supply position 46 (see fig. 4). The plate guide 14 has a substantially horizontal position in the feed position 46. The transport slide 6 is moved out of the plate guide 14 in order to bring it into the supply position 46. In this case, the rollers 8, which carry the conveyor slide 6 at their front ends, move on the guide 7. The guide elements 7 each have a rising section (so-called ramp) and are fastened to the plate cylinder 2. The guide elements 7, when positioned, cause the printing plate guide 14 to pivot slightly about the joint 13 together with the transport carriage 6 supported in the printing plate guide.

Fig. 4a shows that the roller 8 rests against a front stop or positive stop 9, which limits the extension travel of the transport slide 6 and is fixed to the forme cylinder 2. The plate cylinder 2 is divided with respect to its geometric cylinder axis of rotation 45 into two imaginary axial sections, one of which is a cylinder half placed towards the operating side of the printing press 1 and the other is a cylinder half placed towards the drive side. One axial section is referred to as an operation side section 10, and the other axial section is referred to as a drive side section 11. One guide 7 and one positive stop 9 are located in the operating-side section 10, and the other guide 7 and the other positive stop 9 are located in the drive-side section 11. The geometric rotation axes of the rollers 8 are centered with respect to each other and parallel to the drum rotation axis 45. When adjusting it into the supply position 46, the plate guide 14 is oriented laterally by means of a lateral or transverse stop 47 and is centered with respect to the plate cylinder 2. The transverse stops 47 are rollers having geometric roller axes of rotation 49 that are parallel to each other and perpendicular to the roller axis of rotation 45. In the supply position 46, the plate guide 14 is located between two lateral stops 47 fixed to the machine frame.

Fig. 4b shows a variant in which the transverse stop 47 is not configured as a roller externally to the drum, but as a measuring ring internally to the drum. Round-headed pins, which are coaxial to the rollers 8 of the transport slide 6 and are fixed to the latter, rest against the sides of the two measuring rings of the forme cylinder 2 facing each other in order to orient the forme guide 14 laterally.

Fig. 5 shows that the transport slide 6 transports the printing plates 4 in the transport direction 16 toward the plate cylinder 2 and grips them here by means of integrated holding devices. The holding means is a clamping means 17 having a first clamping surface 19 and a second clamping surface 20 on a clamping post 18. A clamping device 3 is arranged on the plate cylinder 2, into which the printing plates 4 are guided by means of a plate guide 14. The transport slide 6 moves the leading edge of the printing plate 4 into the clamping device 3 of the plate cylinder 2. The plate cylinder 2 has a further clamping device, not shown, to fix the trailing edge of the printing plate 4.

Fig. 6 shows that, when the printing plate 4 is clamped between the two clamping

surfaces

19, 20, the first clamping surface 19 is loaded by a spring 21 which generates a clamping force. The clamping post 18 is urged towards the second clamping surface 20 by a spring when clamping and is retracted against the action of the spring 21 by an actuator 22 when unclamping. The actuator 22 is a pneumatic cylinder. The two

clamping surfaces

19, 20 each have an extension which, viewed in the conveying direction 16, is terminated, which is indicated by an arrow in fig. 5.

Fig. 7 shows that the displacement movement of the transport slide 6 in the transport direction 16 and in the opposite direction is driven by an electric motor 23 via a transmission 24. A motor 23 and a transmission 24 are arranged in the plate guide 14. The transmission 24 is a traction mechanism transmission and has a toothed belt 26 as a transmission member and a pulley 25 around which the toothed belt is wound. The motor 23 may be driven indirectly through an intermediate member or, as shown, directly through one of the pulleys 25. The conveyor slide 6 is fixed to the toothed belt 26 and guided in a linear guide, not shown.

Fig. 8 shows that the printing plate 4 has two register punches (so-called mating holes) 28 in its front edge, into which a set of first register pins (so-called mating pegs) 29 can be inserted. A first registration pin 29 is fixed in plate well 12 (see fig. 3). A set of second registration pins 30 is fixed to the clamping devices 3 of the plate cylinder 2 and is inserted into the registration punches 28 when the printing plates 4 are clamped in the clamping devices 3. The diameter of the second registration pin 30 is slightly smaller than the diameter of the first registration pin 29. For example, the diameter of the first registration pin 29 is ten centimeters and the diameter of the second registration pin 30 is nine centimeters, wherein the difference in diameter is 1 centimeter and thus 10%. The difference in diameter may be 5% to 20%.

During operation without interference, the second registration pin 30 is inserted with a loose fit into the registration punch 28 without contacting the printing plate 4, and the correct registration position of the printing plate 4 relative to the clamping device 3 is ensured by the interaction of the first registration pin 29 with the clamping device 17, the transport slide 6 and the

stops

9, 47. In the event of disturbances (misalignments) and manual printing plate equipment, the second registration pins 30 come into contact with the printing plates and the second registration pins 30 cause a rough registration of the printing plates 4, which is achieved by means of the registration adjustment of the plate cylinder 2 after the printing plates 4 are clamped.

Fig. 9a shows that when the printing plate guide 14 is tilted inward into the printing plate well 12 and is in its vertical position, the first registration pin 29 is inserted into the registration punch 28. In this case, the first register pin 29 rests against the middle section of the u-shaped edge of the register punch 28.

As can be seen in fig. 8, the middle section of one register punch 28 is straight and the middle section of the other register punch 28 is semicircular, and the two middle sections are each located between two mutually parallel lateral sections of the edge of the respective register punch 28. In the correctly registered state of the printing forme 4, the clamping device 17 of the transport carriage 6 is closed and the printing forme 4 is clamped in said clamping device.

Fig. 9b shows the return movement of the transport slide 6 and the clamped printing plate 4 in the first direction 31, the transport slide moving upward in the printing plate guide 14, which is also vertical. As a result, a free space 33 is produced between the middle section of the respective register punch 28 and the corresponding register pin 29.

The free space 33 can be dimensioned such that the register pins 29 are either (as in the drawing) still inside the register punches 28 or (differently from the drawing) already outside the register punches 28.

Fig. 9c shows that the printing plate 4 is lifted with respect to the first alignment pins 29 and is thus oriented such that the printing plate 4 can be moved forward in the second direction 32 (see fig. 9d) without colliding with the first alignment pins 29. When lifting up the printing plate 4, it performs a movement with a component of movement perpendicular to the movement in the first direction 31 and the second direction 32. Said movement component is oriented parallel to the horizontal central axis of the first registration pin 29. The lifting of the printing plate 4 is effected by the plate guide 14 being turned out of the printing plate well 12, wherein the plate guide 14 is pivoted about the joint 13 (see fig. 3) into the supply position. That is to say, the movement with the described movement component is a pendulum movement or a flip-out movement and is illustrated in fig. 9c by a curved arrow. In this movement, the printing plate 4 is held stationary in the clamping device 17, which can also be referred to as a holding device. The clamping device 17 is attached to the transport slide 6, which is attached to the plate guide 14 via a linear guide. Thus, adjustment of the plate guides relative to the plate wells 12 effects movement of the printing plates 4 relative to the first registration pins 29 fixed to the plate wells.

Fig. 9d shows that the clamped printing plate 4 is transported by the transport carriage 6 past the head of the first registration pin 29 in a second direction 32, which coincides with the transport direction 16 (see fig. 5 or 8). When the transport slide 6 is moved forward in the second direction 32, the transport slide 6 is moved into the supply position 46. In this case, the printing plate 4 is pushed into the open clamping device 3 of the plate cylinder 2, and the second registration pins 30 of the clamping device 3 are inserted into the registration punch holes 28.

An electronic control unit 34, which is only schematically illustrated in fig. 2, controls the plate changer 5 according to a program running therein. The control device 34 controls, for example, the actuator 22 and the motor 23. The program comprises program steps corresponding to the method steps shown in fig. 9a-9 d.

Fig. 10 shows that a multifunctional element 36 is arranged between the roller 42 and the plate changer 5, which element can be pivoted about a hinge 44 into a first position 39 and a second position 40. The first position 39 shown in phantom is a printing plate guiding position and serves to guide a printing plate 43 to be removed from the plate cylinder 2 to the plate well 12. The printing form 43 is a flexible printing form for spot printing, like the printing form 4 already described above, wherein the two

printing forms

4, 43 differ from one another in terms of the printing image and are provided for different printing jobs, so that a change of printing form is necessary. The printing plate 43 to be guided out slides on the guide surface 37, which is formed by the concave inner side of the multifunctional element 36. The multifunction member 36 is a housing and is swingably supported by carrying arms on both ends of the multifunction member 36. The second position 40, shown in solid lines, is a spray-protected position and serves to collect liquid (lacquer) 50 which is inevitably sprayed out of the rotating roller 42 in the direction of the printing forme wells 12. The droplets of liquid 50 thrown off by the roller 42 impinge on the spray protection surface 38, which is formed by the convex outer side of the multifunctional element 36. Plate well 12 is a sensitive member 41 of plate changer 5, which is protected from contamination by ejected liquid 50 by multi-function element 36. The first position 39 and the second position 40 are diametrically opposed, i.e. offset from one another by an angle of rotation of 180 °, wherein the angular offset can in other applications be a difference of at most 90 ° greater than or less than 180 °.

List of reference numerals

1 printing machine

2 printing plate cylinder

3 (of the plate cylinder 1) clamping device

4 (for spot painting and/or for flexographic printing) printing forms

5 plate changer

6 (sliding or rolling) conveyor slides

7 guide (as a positioning element)

8 (on the conveying sliding plate 6) roller

9 stop, front stop (as a positioning element)

10 (of the plate cylinder 2) operating-side section

11 (of the plate cylinder 2) drive-side section

12 printing plate well

13 hinge

14 plate guide

16 (of the printing formes 4) direction of conveyance

17 holding device, clamping device (of the transport carriage 6)

18 clamping post

19 (on the clamping post 18) first clamping surface

20 second clamping surface

21 spring

22 actuator

23 Motor

24 driving device

25 Belt wheel (as transmission component)

26 cog belt (as transmission component)

28-register punching

29 first alignment pin (alignment pin pair on printing plate well 12)

30 second alignment pin (alignment pin pair on the clamping device 3)

31 first direction (transport printing plate 4 backwards)

32 second direction (forward transport printing plate 4)

33 free space

34 control device (programmable)

36 multifunctional element

37 guide surface

38 spray protection surface

39 first position (plate guide position)

40 second position (spray protection position)

41 Member (corresponding to plate guide 14)

42 roller

43 printing plate

44 hinge

45 drum rotation axis

46 (of the plate guide 14 and its transport carriage 6)

47 transverse stop

48 japanning device

49 axis of rotation of roller

50 liquid

Direction of observation of BR

Claims

1. A printing plate changer for flexographic printing plates in printing presses, comprising a clamping device (17) having a first clamping surface (19) and a second clamping surface (20) which end in a transport direction (16) of a printing plate (4), between which the printing plate (4) can be clamped, the clamping device (17) being fixed to a transport carriage (6) which can be moved in the transport direction (16), wherein the transport carriage (6) can be driven in the transport direction (16) by means of a motor (23) via a transmission (24).

2. A plate changer according to claim 1, wherein the clamping device (17) is arranged inside the transport slide (6) such that the clamping device (17) grips the printing plate (4) in the foremost quarter of the printing plate (4), which is the foremost quarter of the printing plate (4) in the transport direction (16) when transporting the printing plate (4) to a plate cylinder (2).

3. A plate changer according to claim 1 or 2, wherein the first clamping surface (19) is configured on a clamping column (18) which can be adjusted into a clamping position perpendicular to the conveying direction (16).

4. A plate changer according to claim 3, wherein the clamping column (18) is adjustable into the clamping position by a spring (21).

5. A plate changer according to claim 4, wherein the clamping column is adjustable away from the clamping position against the action of the spring (21) by an actuator (22).

6. A plate changer according to claim 5, wherein the actuator (22) is a pneumatic cylinder.

7. A plate changer according to claim 1, wherein the transmission (24) is a belt transmission and/or a transmission having toothed transmission members.

8. A plate changer according to claim 7, wherein the belt drive comprises a toothed pulley (25) and a toothed belt (26).