JP2002361828A - Sheet guide cylinder provided in multicolor printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet guide cylinder provided in a multicolor printer and having a base which includes a flat part for removably providing a body cover, in such a manner that the cylinder can simply guide particularly a sheet in which a no stain is adhered and can be mounted in a short time. SOLUTION: Coating surfaces of respective body covers 7 and 8 are formed to have a diameter R in an envelope circle 9 formed of a sheet gripper mechanism, removably arranged on the base 6, and coatings which repel an ink or a varnish are fixed to the surfaces of the covers 7 and 8. Each coating is formed of a metal such as chromium, iron, titanium, nickel, cobalt, tungsten, molybdenum or the like or contains at least these components.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet guide cylinder provided in a multicolor printing press according to the first aspect of the present invention.

[0002]

2. Description of the Related Art A sheet-fed guide cylinder of the same kind is known from DE-A 125 46 645 as a transfer cylinder having a double diameter, such a transfer cylinder being composed of a driven base body and having two right and left sides. It has a symmetric flat part. In the flat part, a member forming a segment-shaped trunk portion, also called a trunk cover, is detachably provided. These cylinders are also provided with a coating of ink-repellent material for a particular printing order. The coating is made of an ink-repelling material and is provided on the body cover by an extension member.

[0003] The first invention which develops the above-mentioned invention is known from DE-A-4110309. According to the invention, a fastening shaft for a planar object made of fibers is arranged on the body cover, the first fastening shaft being a spare shaft for the planar object made of fibers, and the second fastening shaft being a flat surface made of fibers. It is formed as a winding shaft for the object.

[0004] In a second embodiment described in DE-A-195 13 427, a sheet guide cylinder having a drum cover is described, in which a flat circumferential surface of the sheet guide cylinder has perforations. Is formed. An overlay made of fiber is provided on the body cover so as to be movable with respect to the body cover. It is disadvantageous when providing a tightening shaft that the planar shaped article made of fibers does not have a guide of the lateral circumferential surface. That is, tightening may occur. In addition, such sheet guide cylinders are limited to operation only with planar shaped objects made of fibers (DE 41 10 309, DE 195 1342).
No. 7). In the case of using a body part without a fiber overlay, there is no description that the sheet is guided without contamination (German Patent No. 1254645).
issue).

[0005] DE-A 29 14 255 discloses single-layer or multi-layer coatings for sheet guide cylinders. The coating has an oleophobic and abrasion resistant outer layer with a minimum content of 30% nickel and / or chromium. In addition to nickel and / or chromium contained at such a minimum content, additives of elements such as molybdenum, tungsten, cobalt, aluminum, boron, manganese, titanium, magnesium and cerium are supplied. The pores of such an outer layer are preferably filled with a sealant made of Teflon (registered trademark) or copy varnish.

[0006] DE 100 39 912 discloses a coating for an impression cylinder. According to the invention, the outer surface of the coating on the printing material side has a fabric, which is preferably made of metal. A disadvantage in this case is that the coating may wear on the coating surface due to relative movement between the cylinders. Scratches can also occur, which can have a detrimental effect on the sheet material guide and on the print quality.

[0007] DE-A-198 50 968 describes a wear-resistant and ink-repellent coating for components used in the printing industry. This coating contains metal oxides or cemented carbides, 100 ° C
To 170 ° C. and a sealant comprising organopolysiloxane groups.

[0008]

The object of the present invention is to provide a sheet guide cylinder of the type mentioned at the outset, which avoids the disadvantages mentioned above and which is particularly simple and clean. It is possible to provide something that can be installed in a short time.

[0009]

This problem is solved by the features of the first aspect. Further configurations are described in the dependent claims.

A first advantage is that at least one cylinder cover is provided on the cylindrical body of the sheet guide cylinder in a rapidly removable manner. This ensures that the mounting time is shortened and that the use of sheet guide cylinders can be made more universal. Thus, in a first mode of operation of the sheet guide cylinder, for example, when an unprinted or already dried surface of a printed or varnished sheet material is guided to the sheet guide cylinder,
It can be operated without having a torso (s). In the second mode of operation, the sheet guide cylinder may be provided with at least one surface having an ink or varnish repellent surface, in particular when the sheet has just been printed or varnished and guided by the sheet guide cylinder. Two torso covers are provided. These modes of operation are not limited to the difference between single-sided or double-sided printing, but are also dictated by the nature of the paper of the printing material to be processed.

[0011] A further advantage is that it is not necessary to removably provide the body cover with a planar shaped object made of fiber.
The reason is that the surface of the cylinder cover facing the printing material is provided with a coating that repels ink or varnish.

It is also advantageous that the arrangement of the drum cover removably mounted on the base of the sheet guide cylinder is not limited to sheet guide cylinders having the same diameter.
Assuming that the diameter of the plate cylinder is 1, for example, double, triple, or four
A sheet guide cylinder having a double diameter is realized by arranging a plurality of cylinder covers on the circumferential surface.

A further advantage is that the torso cover has a depression. That is, the diameter of the body cover having the base is smaller than that of the envelope circle (theoretical diameter) formed by the holding mechanism.
As a result, the printing material is guided into the covering of the respective cylinder cover (having a smaller diameter with respect to the envelope circle) and a larger space is provided between the cylinder cover and the optionally adjacent sheet guide device. The advantage is that a free space is created. In this way, the sheet can run quietly on the sheet guide cylinder.

Finally, it is advantageous that such a sheet guide cylinder can be used universally for both single-sided and double-sided printing.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail based on embodiments. The following is shown in the figure.

The sheet-fed rotary printing press has at least a printing device or a varnishing device for multicolor printing.
Each printing device has a sheet guide cylinder as an impression cylinder 4, a transfer cylinder 2 is arranged on the impression cylinder 4, and a plate cylinder 3 is arranged on the transfer cylinder 2. At least one transport cylinder 5 for transporting the sheet to an adjacent printing device is provided between each impression cylinder 4 which guides the printing device, in particular the sheet. In this embodiment (FIG. 1), a contact cylinder 1 is provided as a sheet guide cylinder upstream of the impression cylinder 4 of the first printing apparatus.

In the present embodiment, the transport cylinder 5 is formed to be twice as large, and has a cylindrical base 6 which is supported on the frame side. This substrate is provided with two sheet holding mechanisms symmetrically (shifted by 180 ° C.) on the circumferential surface. As is known, for example, from DE-A 12 546 645, the base body 6 has two secant flats.

Further, in order to form a curved circumferential surface on a flat portion of the base 6, a first body cover 7 and a second body cover 8 are provided detachably at mirror-symmetric positions. Since the torso covers 7, 8 are preferably connected to the flat portion of the base body 6 by using bolts 13 such as fixing bolts and screws 12, the torso covers 7, 8 can be quickly attached or detached.

The body covers 7, 8 preferably have an abutment surface 11 in order to bring the body covers 7, 8 into contact with the correct position of the flat part of the base 6. Since these contact surfaces 11 are provided on the covering surfaces at the ends of the body covers 7, 8 when viewed from the circumference, the contact surfaces 11 are attached to the sheet holding mechanism of the base 6 in a mounted state. It will be provided in the vicinity.

When the body covers 7, 8 are formed from a flexible metal material such as stainless steel, at least one support 14 is preferably connected to the back of each body cover 7, 8 at an axial position. Have been. The struts 14 are preferably formed as support ribs and are provided radially with respect to the axis of the sheet guide cylinder (base 6) behind the covering surface of the respective cylinder cover. Alternatively,
A number of columns 14 may be provided at a certain distance from each other in the axial direction of the base 6.

A coating 10 for repelling ink or varnish is provided on the covering surface of each of the cylinder covers 7 and 8,
Such a coating is fixed to the flexible covering surfaces of the torso covers 7,8. The coating 10 is formed with low wear and a suitable structure. The layer thickness of the coating 10 is preferably between 10 μm and 120 μm, and the preferred roughness R _Z is between 5 μm and 60 μm.

In order to convey the sheet without soiling,
The coating 10 preferably has a cross-sectional top 16 on the end side, has as small a proportion of the contact surface as possible, and
7 is formed with an irregular surface structure as if the convex portions (cone 15) were accidentally distributed so as to reduce the number as much as possible.

Coating 10 having the shape of a cone 15
A sealing layer 18 is preferably fastened to the surface section of the cone, which conforms substantially to the contour of the cone 15. Surface cross section of trunk covers 7, 8 in which coating 10 and sealing layer 18 are provided on a flexible metal supporting material (FIG. 5)
Have individual and / or rounded cross-sectional tops 16
Alternatively, it is characterized in that it has a conical body 15 which is spaced apart in a chain.

Such a surface structure of the coating 10 can be realized by the coating process itself or by subsequent erosion of the coating 10. Furthermore, the pre-treatment of the covering surfaces of the body covers 7, 8 (prior to the application of the coating 10) can be performed by light, brush, embossing, engraving, galvanic corrosion, laser treatment or purely chemical or electrochemical etching. Is realized by:

The coating 10 comprises the following metals: - chromium, iron, titanium, nickel, cobalt, or tungsten - the metal _{oxides: Al 2 O 3, TiO 2} , Cr 2 O 3,
SiO ₂ or ZrO _2- Carbide of the metal: WC or Cr ₃ C _2- Silicide, mixture or alloy of the metal

The coating 10 is preferably applied to the covering surfaces of the body covers 7, 8 which guide the sheets by flame spraying. Pure molybdenum is used as a particularly suitable material for the coating 10. Molybdenum, in addition to its favorable sliding properties, exhibits a high degree of strain hardening when subjected to mechanical loads, so that it requires less operating time, does not sustain sustained scratches and transports low-wear sheets. An optimally cured surface is obtained as the coating 10 for performing Such surface slip characteristics can be enhanced by the interaction of molybdenum with the sulfide component of the ink combined with mineral oil, since a very thin molybdenum disulfide (MoS ₂ ) layer is formed during operation.

As another method, molybdenum disulfide is added to the coating powder in a proportion of 30% by volume or less,
Such excellent sliding properties of the molybdenum layer can also be immediately effective. Coating 1
0 is provided directly on the body covers 7, 8 or indirectly using an adhesive medium such as a nickel-chromium alloy as an intermediate layer. If necessary, the surface structure of the coating 10
It is improved by lightly polishing the surface or removing irregularities later.

The ink or varnish-repelling property of the surface having the structure of the coating 10 is determined by the sealing layer 18 or
Improved by ink or varnish repelling particles. The particles are applied, for example, by spraying the powder with a flame or applying it later. The sealing of the coating 10 is achieved by a material with a low surface energy (sealing layer 18). Fluorocarbon such as acrylate or PTFE for the sealing layer
For example, a fluoropolymer based on (polytetrafluoroethylene) or a copolymer containing fluorine is used. Alternatively, an inorganic or organic hybrid (hybrid) polymer can be provided on the surface. Such hybrid polymers are composed of organic Si-Si network bonds and inorganic Si-O network bonds. Active groups such as alkyl groups, vinyl groups or metal oxides are deposited on these hybrid polymers.

As another method, an organic polysiloxane, a hydrocarbon residue of the organic polysiloxane, preferably a methyl group is used as the sealing layer 18, but other alkyl groups such as a phenyl group or an allyl group are also used. These compounds can further incorporate halogenated groups, especially F or F-compounds. The coating 10 is preferably made of a sealant comprising an organic polysiloxane group (sealing layer 1).
8) is fixed and faces the printing material in that state.
The adhesion and abrasion resistance of the sealing layer 18 is approximately 50%.
It can be increased by curing at a temperature of from 450C to 450C.

Torso covers 7, 8 having a coating 10
(And optionally the sealing layer 18) are geometrically
A recess is provided in the circumferential surface (between the sheet holding mechanisms). When the transfer cylinder 5 having the envelope circle 9 formed by the sheet holding mechanism is rotated, the cylinder cover 7 attached to the cylinder main body 6 has a diameter corresponding to the rotation diameter.
The diameter 8 or the radius R of each body cover 7, 8 is smaller than the envelope circle 9 (when viewed individually).

For example, when the diameter of the envelope circle 9 formed by the sheet holding mechanism is 600 mm, the body covers 7 and 8 (including the base 6) are formed to have a diameter of 580 mm or a radius R of 290 mm. ing. A sheet guide device (not shown), which is preferably provided outside the sheet transport surface, is arranged adjacent to such a sheet guide cylinder, in this case the transport cylinder 5. In this case, a larger free space is realized between the sheet guide device and the covering surfaces of the body covers 7, 8 in order to guide the sheets so that they are not stained.

Such a free space is suitable for opening the printing material (after passing through the printing gap) and
When the sheet-shaped printing material travels on a curve, the cylinder covers 7, 8
Are guided sufficiently by means of a covering surface and a suitably arranged sheet guiding device.

The configuration of the sheet guide cylinder having the cylinder covers 7 and 8 which are detachably provided so as to have recesses is not limited to the configuration of the transport cylinder 5 which is twice as large, but rather, the base 6 and A sheet guide cylinder of equal size having a body cover 7 or a base body 6 respectively
And a three or four times larger sheet guide cylinder having three or four body covers 7, 8 provided symmetrically on the circumference of the base 6. .

The arrangement according to the invention is also not restricted to the transport cylinder 5, but can be used for all sheet guide cylinders, such as contact cylinders, return cylinders, impression cylinders, unloading cylinders (delivery devices). For example, in the delivery device, by forming the base body 6 as a chain gear shaft, at least one body cover 7, 8 can be detachably provided on this shaft. The coating 10 is also fixed to the body covers 7 and 8, and the coating 10 is provided with a sealing layer 18 made of an organic polysiloxane group. In this way, the delivery device can be operated by a take-off cylinder (comprising at least one cylinder cover 7, 8 on a base body 6 formed as a chain gear shaft) or, if the cylinder cover 7, 8 is removed, by a chain. It can be driven by a gear shaft (base 6).

[Brief description of the drawings]

FIG. 1 shows a sheet-fed rotary printing press with a sheet guide cylinder.

FIG. 2 is a side view of a trunk cover.

FIG. 3 is a rear view of the trunk cover.

FIG. 4 is a perspective view (rear view) of a trunk cover.

FIG. 5 is a surface sectional view (partially enlarged view) of a vertical section.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Contact cylinder 2 Transfer cylinder 3 Plate cylinder 4 Impression cylinder 5 Conveying cylinder 6 Base 7 First trunk cover 8 Second trunk cover 9 Envelope circle 10 Coating 11 Contact surface 12 Screw 13 Bolt 14 Column 15 Conical body 16 Cross section Top 17 Concave recess 18 Sealing layer 19 Radius

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) F16C 13/00 F16C 13/00 EF term (reference) 3J103 AA02 AA52 AA72 FA09 FA17 GA54 HA54 4K044 AA03 BA02 BA06 BA12 BA18 BA19 BA21 BB01 BB03 CA01

Claims (9)

[Claims] 1. A sheet guide cylinder for a multicolor printing press, comprising: a cylindrical substrate, at least one disposable sheet holding mechanism, and a releasably mounted on said substrate. A sheet guide cylinder having at least one cylinder cover, wherein the covering surface of each cylinder cover (7, 8) has a radius () inside an envelope circle (9) formed by said sheet holding mechanism. R), and is detachably provided on the base (6);
An ink or varnish repelling coating (10) is adhered to the surface of the body cover (7, 8), and the coating (10) is formed of a metal such as chromium, iron, titanium, nickel, cobalt, tungsten or molybdenum. Or a sheet guide cylinder comprising at least these components. 2. A sheet guide cylinder according to claim 1, wherein a sealing layer (18) comprising an organic polysiloxane group is adhered to the coating (10). 3. The sheet guide cylinder according to claim 1, wherein the coating (10) is formed of an oxide, carbide or silicide, mixture or alloy of the metal. 4. The at least one cylinder cover (7, 8) has at least one strut (14) provided on the back side in a radial direction with respect to the axis of the sheet guide cylinder. 2. The sheet guide cylinder according to claim 1. 5. The torso cover (7, 8) has at least one abutment surface (11) on the rear side, said abutment surface coinciding with a flat part of the body (6) of the torso. A sheet guide cylinder according to claim 1. 6. The sheet guide cylinder according to claim 1, wherein the body covers (7, 8) are provided symmetrically on the circumferential surface of the base (6). 7. The coating (10) having a thickness of 10 μm or less.
2. The sheet guide cylinder according to claim 1, wherein the sheet guide cylinder has a layer thickness of 120 [mu] m. 8. The cylinder cover (7, 8) has at least a surface shape consisting of a cone (15) having a rounded top (16) on the side facing the printing material. Item 1. A sheet guide cylinder according to item 1. 9. The base (6) is a chain gear shaft of a feeding device, and at least one body cover (7, 8) includes a coating (10) and a sealing layer (18) composed of an organic polysiloxane group. The sheet guide cylinder according to claim 1, wherein the sheet guide cylinder is provided so as to be detachable from the chain gear shaft.