JPH08142305A - Plate cylinder for rotary printing device - Google Patents

Abstract

PURPOSE: To provide a plate cylinder for a rotary printing device with which those parts unusable for printing of a press plate to be attached to a predetermined position on an outer peripheral face of a plate cylinder body can be reduced. CONSTITUTION: A plate cylinder of a rotary printing device comprises a plate cylinder body 10 having a cylindrical shape and an outer peripheral face on which a press plate H is to be wound and a press plate suction means for attaching the press plate on the outer peripheral face of the plate cylinder body in a sucking manner. The press plate suction means comprises a large number of suction holes 26 arranged on the outer peripheral face of the plate cylinder body 10, a through hole 22 of one central axis 14a communicating with the internal cavity of the plate cylinder body 10, a suction tube 24 connected to the through hole 22, and a vacuum source connected to the suction tube 24.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate cylinder used in a rotary printing apparatus.

[0002]

2. Description of the Related Art In a plate cylinder of a conventional rotary printing apparatus, a plate is attached to a predetermined position on the outer peripheral surface of a cylinder body having a cylindrical shape by mounting the plate in the circumferential direction of the outer peripheral surface of the plate cylinder body. This is done by detachably fixing both ends to fixing members independent of the plate cylinder body. For this reason, in the case where the printing paper on which the image is transferred from the plate cylinder is a long printing paper drawn from the web, at least the printing plate is placed between the plurality of images sequentially transferred from the plate cylinder to the printing paper. Then, non-printed portions corresponding to the above both ends are generated. This non-printed portion is cut off unless it is used later, resulting in waste of printing paper.

[0003]

In recent years, for example in offset rotary printing machines, so-called gapless offset rotary printing machines have become known which include a blanket cylinder in which the blankets are mounted substantially seamlessly. For this reason, if the areas that cannot be used for printing, such as the above-mentioned both ends of the plate attached to the outer peripheral surface of the plate cylinder main body, are minimized, they are sequentially transferred to the long printing paper. The non-printed portion that occurs between the plurality of images is reduced. That is, the number of images that can be printed in the longitudinal direction of one roll of roll paper (one long print sheet) is increased as compared with the case of a conventional offset rotary printing device that is not gapless. Can be done.
This results in a reduction in the number of webs used and a less frequent supply of new webs, which in turn leads to a reduction in printing costs.

The present invention has been made under the above circumstances, and an object of the present invention is a rotary printing apparatus capable of reducing a portion which cannot be used for printing in a printing plate mounted at a predetermined position on the outer peripheral surface of a plate cylinder main body. Is to provide a plate cylinder.

[0005]

In order to achieve the above-mentioned object of the present invention, a plate cylinder of a rotary printing apparatus according to the present invention has a cylindrical shape and an outer peripheral surface around which a printing plate is wound. And a plate adsorbing means for adsorbing a printing plate on the outer peripheral surface of the plate cylinder main body.

[0006]

In the plate cylinder of the rotary printing apparatus according to the present invention, which is configured as described above, the plate has a cylindrical shape and has an outer peripheral surface around which the plate is wound. Is adsorbed to the outer peripheral surface of the plate by the plate adsorbing means.

Therefore, it is not necessary to secure non-printing portions for fixing the plate to the outer peripheral surface at both ends of the plate in the peripheral direction of the outer peripheral surface. Therefore, it is possible to eliminate the non-printed portion between the plurality of images sequentially transferred to the long printing paper, and to print in the longitudinal direction of one roll of roll paper (one long printing paper). The number of images that can be printed can be increased in an offset rotary printing apparatus, for example, as compared with a conventional offset rotary printing apparatus having a non-gapless blanket cylinder. This is true for all rotary printing devices. This results in a reduction in the number of webs used and a less frequent supply of new webs, which in turn leads to a reduction in printing costs.

In the plate cylinder of the rotary printing apparatus according to the present invention, which is characterized in that it is constructed as described above,
On the outer peripheral surface of the plate cylinder main body, there may be installed a printing plate positioning means for positioning one end edge portion of the printing plate at a predetermined position on the outer peripheral surface.

By positioning one edge of the printing plate by the printing plate positioning means, the printing plate can be easily positioned with respect to a predetermined position on the outer peripheral surface of the plate cylinder main body, and the non-printed portion can be reduced.

The printing plate positioning means may include a positioning slit which is provided at a predetermined position on the outer peripheral surface of the plate cylinder main body and into which one end edge of the printing plate is inserted and engaged. Since the positioning slit has a simple structure, and one edge of the printing plate that is inserted into the positioning slit and engaged and cannot be used for printing is not exposed on the outer peripheral surface of the plate cylinder main body, it is on the outer peripheral surface of the plate cylinder main body. The image of the printing plate exposed at can be made substantially seamless.

A positioning hole is formed at one edge of the plate and a plate positioning means is provided at a predetermined position on the outer peripheral surface of the plate cylinder main body and is removably inserted into the positioning hole at the one edge of the plate. It may include a locating pin that is worn.

Further, the positioning pin of the printing plate positioning means can be retracted to and from the outer peripheral surface of the plate cylinder main body, and the printing plate positioning means can include a biasing means for biasing the positioning pin toward the projecting position. . When the plate cylinder is used in combination with the blanket cylinder or the dressing roller, the plate positioning means having such a structure does not damage the outer peripheral surface of the blanket cylinder or the dressing roller by the positioning pin.

Further, the positioning pin of the printing plate positioning means is allowed to freely project and retract with respect to the outer peripheral surface of the plate cylinder main body, and the printing plate positioning means selectively moves the positioning pin between the projecting position and the retracting position. Means of transportation can be included. In the printing plate positioning means having such a structure, after the positioning of the printing plate with respect to the predetermined position on the outer peripheral surface of the plate cylinder main body is once completed, the positioning pin selection moving means moves the positioning pin from the protruding position to the retracted position. Then, when the plate cylinder is used in combination with the blanket cylinder or the dressing roller, the outer peripheral surface of the blanket cylinder or the dressing roller is not damaged by the positioning pin.

The plate suction means is connected to a suction hole provided in the plate cylinder main body and opened to the outer peripheral surface of the plate cylinder main body, and communicates with the inner end of the suction hole in the plate cylinder main body to suck the outer peripheral surface of the plate cylinder main body. Negative pressure generating means for generating a negative pressure at the opening of the hole. Alternatively, the printing plate may include a magnetic material, and the printing plate suction means may include an electromagnet that applies a magnetic force to the outer peripheral surface of the plate cylinder main body.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A plate cylinder of a rotary printing apparatus according to various embodiments of the present invention will be described in detail below with reference to the accompanying drawings. [First Embodiment] FIG. 1A is a schematic vertical sectional view of a plate cylinder of a rotary printing apparatus according to a first embodiment of the present invention, and FIG. FIG. 2 is a schematic cross-sectional view for explaining the operation of the plate cylinder of FIG. 1 (A).

As shown in FIG. 1A, the first aspect of the present invention
The plate cylinder of the rotary printing apparatus according to the embodiment of the present invention includes an outer cylinder 10 which is a cylindrical plate cylinder body. The openings at both longitudinal ends of the outer cylinder 10 are closed by a pair of side walls 12a and 12b, and the pair of side walls 12a and 12b are detachably fixed to the end walls at both longitudinal ends of the outer cylinder 10. There is. The pair of side walls 12a and 12b are concentrically arranged with respect to the outer cylinder 10.
A pair of central axes 14a and 14b are formed. The pair of central shafts 14a, 14b are rotatably supported by a frame (not shown) of a rotary printing apparatus using the plate cylinder via a pair of bearings 16a, 16b.

A rotating force input gear 1 for rotating the plate cylinder in a predetermined direction at a predetermined speed by inputting a rotational force from a rotation driving means (not shown) to one of the central shafts 14a.
8 is fixed concentrically.

In this embodiment, an inner cylinder 20 is concentrically arranged inside the outer cylinder 10, and both longitudinal ends of the inner cylinder 20 are supported by a pair of side walls 12a, 12b.
However, the inner cylinder 20 is not always necessary.

A through hole 22 extending in the longitudinal direction is also formed concentrically on one of the central shafts 14a. The other end of a suction tube 24, one end of which is connected to a negative pressure source (not shown), is airtightly and relatively rotatably connected to the outer end of the through hole 22 of the one central shaft 14a.

The outer cylinder 10 has a large number of suction holes 26 penetrating from the outer peripheral surface to the inner peripheral surface. Further, on the outer peripheral surface, a positioning mark is formed as a plate positioning means for positioning the printing plate mounted on the outer peripheral surface.

In order to mount and fix the printing plate at a predetermined position on the outer peripheral surface of the outer cylinder 10 of the above-described embodiment, first, from the inner space of the outer cylinder 10 whose rotation is stopped, the negative plate (not shown) described above is used. Air is sucked through the pressure source, the suction pipe 24, and the through hole 22 of the one central shaft 14a. As a result, negative pressure is generated in the large number of suction holes 26 on the outer peripheral surface of the outer cylinder 10.

At a predetermined position on the outer peripheral surface of the outer cylinder 10,
As shown in FIG. 1B, a predetermined edge Ha of the printing plate H (for example, the upper edge of the printing image formed on the printing plate H) is aligned, and then the other end of the printing plate H is aligned. Outer cylinder 10 gradually toward the edge
The printing plate H is wound around the outer peripheral surface of. As a result, the printing plate H is adsorbed and fixed at a predetermined position on the outer peripheral surface of the outer cylinder 10 by the negative pressure L in the inner space of the outer cylinder 10.

The negative pressure in the internal space of the outer cylinder 10 increases as the area on which the printing plate H is wound around the outer peripheral surface of the outer cylinder 10 increases. The load is increased, or recesses are created in a large number of positions on the outer peripheral surface of the outer cylinder 10 corresponding to a large number of suction holes 26 in the printing plate H to form a large number of non-printing spots in the printed image of the printing plate H. In order to prevent the negative pressure, a negative pressure detector (not shown) is installed in the suction pipe 24, so that the negative pressure (not shown) described above is maintained in order to keep the negative pressure in the internal space of the outer cylinder 10 at a predetermined value. I try to control the operation of the source.

Further, in the printing plate H, recesses are created in a large number of locations on the outer peripheral surface of the outer cylinder 10 corresponding to a large number of suction holes 26, and a large number of non-printing spots are formed in the printed image of the printing plate H. In order to prevent the occurrence of this, a region where a printed image is formed is predetermined in the printing plate H wound around the outer peripheral surface of the outer cylinder 10 with a large number of suction holes 26 formed on the outer peripheral surface of the outer cylinder 10. If so, the outer cylinder 10 that does not correspond to this image forming area
It is also possible to form the suction holes 26 only in the region of the outer peripheral surface of the.

As described above in detail, in the first embodiment of the present invention, the negative pressure source (not shown), the suction pipe 24, the through hole 22 of the one central shaft 14a, and the outer peripheral surface of the outer cylinder 10 are provided in large numbers. The suction holes 26 constitute a plate suction means for sucking the plate H onto the outer peripheral surface of the outer cylinder 10. [Second Embodiment] FIG. 2A is a schematic cross-sectional view for explaining the operation of the plate cylinder of the rotary printing apparatus according to the second embodiment of the present invention.

The basic structure of the second embodiment is the same as the basic structure of the first embodiment shown in FIG. 1, and only the different structure will be described below. Outer cylinder 1 of the plate cylinder of the second embodiment
On the outer peripheral surface of 0 ', a plate is placed at a predetermined position for positioning a predetermined edge Ha of the plate H on the outer peripheral surface (for example, an upper edge of a printing image formed on the plate H). A positioning slit S into which a predetermined edge Ha of H is inserted and engaged is formed.

With such a construction, the large number of suction holes 26 formed on the outer peripheral surface of the outer cylinder 10 'need only be in the outer peripheral surface of the outer cylinder 10' only in the region near the other edge of the printing plate H. .
Further, as compared with the case of the first embodiment, the positioning of a predetermined edge Ha of the printing plate H (for example, the upper side edge of the printing image formed on the printing plate H) on the outer peripheral surface of the outer cylinder 10 'is performed. It's easy. [Third Embodiment] FIG. 2B is a schematic cross-sectional view for explaining the operation of the plate cylinder of the rotary printing apparatus according to the third embodiment of the present invention. 2C is an enlarged cross-sectional view of the main part of the plate cylinder of FIG. 2B.

The basic structure of the third embodiment is the same as the basic structure of the first embodiment shown in FIG. 1, and only the different structure will be described below. Outer cylinder 1 of the plate cylinder of the third embodiment
On the outer peripheral surface of 0 ', a predetermined position for positioning a predetermined edge H'a of the plate H'on the outer peripheral surface (for example, an upper edge of a printing image formed on the plate H). The positioning pin 30 is installed in the. Further, a positioning hole (not shown) into which the positioning pin 30 is detachably inserted is formed at a predetermined edge H'a of the printing plate H'used in this embodiment.

As shown in FIG. 2C, the positioning pin 30 of this embodiment is screwed into a screw hole 30a formed at a predetermined position on the outer peripheral surface of the outer cylinder 10 ', and the outer peripheral surface is formed. A hexagonal hole 30b is formed on the top surface of the smooth outer surface of the outer projecting portion projecting outwardly from. By inserting a hexagon wrench (not shown) into the hexagonal hole 30b and rotating the hexagonal wrench in one direction or the other direction, the amount of protrusion of the positioning pin 30 from the outer peripheral surface can be easily changed.

In this embodiment, the outward projection of the positioning pin 30 on the outer peripheral surface of the outer cylinder 10 'constitutes the outer peripheral surface of the blanket cylinder when the plate cylinder is used in combination with a blanket cylinder or a roller. The blanket is elastically compressed to be absorbed into the blanket, or a positioning pin escape recess is formed on the outer peripheral surface of the blanket at a position corresponding to the outward protrusion of the positioning pin 30.

FIG. 2D is an enlarged sectional view of the essential parts of the first modification of the plate cylinder of the rotary printing apparatus according to the third embodiment of the present invention. The basic structure of the first modification is the same as the basic structure of the third embodiment shown in FIGS. 2B and 2C, and only the different structure will be described below.

In this modification, the positioning pin 30 'has a through hole 32 formed at a predetermined position on the outer peripheral surface of the outer cylinder 10'.
It is arranged in a so as to be retractable from the outer peripheral surface, and has a protruding position as shown in FIG. 2D protruding from the outer peripheral surface by a predetermined distance and a retracted position retracted inward from the outer peripheral surface. You can move between them. The positioning pin 30 'is provided in the through hole 32a by an urging means 32c such as a compression coil spring interposed between the inner end of the positioning pin 30' and the lid 32b closing the inner opening of the through hole 32a. It is always biased toward the protruding position.

The positioning pin 30 'having such a structure is
When the plate cylinder is used in combination with the blanket cylinder or the dressing roller, when it comes into contact with the outer peripheral surface of the blanket cylinder or the wearing roller, it is positioned at a predetermined position on the outer peripheral surface of the outer cylinder 10 'by the positioning pin 30'. 2D by the urging force of the urging means 32c when it is retracted against the urging force of the urging means 32c to a protrusion height equal to the thickness of the printing plate not shown and is released from the contact. Return to position.

When the plate cylinder is used in combination with a blanket cylinder or an applicator roller, the positioning pin 30 'which can be retracted from the outer peripheral surface of the outer cylinder 10' strongly strengthens the outer peripheral surface of the blanket cylinder or the applicator roller. It is not compressed to damage them, and it is necessary to form a positioning pin escape recess at a position corresponding to the positioning pin 30 'on the outer peripheral surface of the blanket of the blanket cylinder or the wearing roller in order to prevent these damages. There is no.

FIG. 2E is an enlarged cross-sectional view of the essential portions of the second modification of the plate cylinder of the rotary printing apparatus according to the third embodiment of the present invention. The basic structure of the second modification is the same as the basic structure of the third embodiment shown in FIGS. 2B and 2C, and only the different structure will be described below.

In this modification, the positioning pin 30 has a through hole 32a formed at a predetermined position on the outer peripheral surface of the outer cylinder 10 '.
It is arranged so as to be retractable from the outer peripheral surface, and between a protruding position as shown in FIG. 2E protruding from the outer peripheral surface and a retracted position retracted inward from the outer peripheral surface. It can be moved freely. And positioning pin 3
Reference numeral 0 is a positioning pin selecting / moving means 3 such as a plunger / solenoid assembly disposed in the through hole 32a.
The 2f allows selective movement between the protruding position and the retracted position.

It should be noted that the positioning pin selecting / moving means 32f-2
The two conductive wires are provided on a pair of annular conductive rails (not shown) that are concentrically arranged with respect to the rotation center axis 14b corresponding to the outer surface of one side wall 12b of the outer cylinder 10, and on the pair of annular conductive rails. A pair of conductive brushes 34a, 34b that are in sliding contact
Is connected to a control device and a power source (not shown).

The positioning pin 30 having such a structure covers the positioning pin 30 at a predetermined position on the outer peripheral surface of the outer cylinder 10 'with a positioning hole (not shown) at a predetermined edge H'a of the printing plate H'. When fitted, the outer cylinder 10 is moved to the projecting position as shown in FIG. 2 (E) and the plate cylinder is rotated for printing.
It is moved to the retracted position up to a protrusion height equal to the thickness of a printing plate (not shown) positioned at a predetermined position on the outer peripheral surface of ′.

When the plate cylinder is used in combination with a blanket cylinder or an applicator roller, the positioning pin 30 which can be retracted from the outer peripheral surface of the outer cylinder 10 'strongly compresses the blanket of the blanket cylinder or the applicator roller. Therefore, it is not necessary to form a positioning pin escape recess in a portion corresponding to the positioning pin 30 on the outer peripheral surface of the blanket of the blanket cylinder or the wearing roller in order to prevent these damages. . [Fourth Embodiment] FIG. 3 is a schematic vertical sectional view of a plate cylinder of a rotary printing apparatus according to a fourth embodiment of the present invention.
The basic structure of the fourth embodiment is the same as the basic structure of the first embodiment shown in FIG. 1, and only the different structure will be described below.

In this embodiment, the outer cylinder 10 ″ of the plate cylinder is constructed as an electromagnet, and no suction hole is formed on the outer peripheral surface of the outer cylinder 10 ″. A pair of side walls 12'a, 12
′ B is fixed to both ends of the outer cylinder 10 ″ in the longitudinal direction via an insulator 40, and a pair of rotation center shafts 14′a, 14′b of the pair of side walls 12′a, 12′b. No through hole is formed in any of these.

The power supply to the electromagnet of the outer cylinder 10 ″ is not shown by being installed concentrically with respect to the pair of rotation center shafts 14′a and 14′b on both end faces in the longitudinal direction of the outer cylinder 10 ″. This is performed by a pair of conductive brushes 42a and 42b that are in sliding contact with a pair of annular conductive rails.

A positioning mark is formed on the outer peripheral surface of the outer cylinder 10 '' as a plate positioning means for positioning the printing plate mounted on the outer peripheral surface. The plate contains a magnetic material.

In order to mount and fix the printing plate at a predetermined position on the outer peripheral surface of the outer cylinder 10 '' of the above-described embodiment, first, a pair of electromagnets of the outer cylinder 10 '' whose rotation is stopped are paired. Power is supplied through the conductive brushes 42a and 42b to operate the electromagnet.

Then, a predetermined edge of the printing plate (for example, an upper side edge of the printing image formed on the printing plate H) is aligned with a predetermined position on the outer peripheral surface of the outer cylinder 10 ″, and then the printing is performed. The printing plate is gradually wound around the outer peripheral surface of the outer cylinder 10 ″ toward the other edge of the plate. As a result, the printing plate is attracted and fixed to a predetermined position on the outer peripheral surface of the outer cylinder 10 ″ by the magnetic force of the outer cylinder 10 ″. That is, in this embodiment, the electromagnet of the outer cylinder 10 ″ is the outer cylinder 1
A plate adsorbing means for adsorbing the plate to the outer peripheral surface of 0 ″ is configured.

[0045]

As described above in detail, according to the plate cylinder of the rotary printing apparatus according to the present invention, a portion of the printing plate attached to the outer peripheral surface of the plate cylinder main body at a predetermined position which cannot be used for printing is reduced. It can be done.

[Brief description of drawings]

FIG. 1 (A) is in accordance with a first embodiment of the present invention,
It is a schematic longitudinal cross-sectional view of the plate cylinder of the rotary printing apparatus, (B)
FIG. 3 is a schematic cross-sectional view for explaining the operation of the plate cylinder of FIG. 1 (A).

FIG. 2A shows a second embodiment of the present invention,
It is a schematic transverse cross-sectional view for explaining the operation of the plate cylinder of the rotary printing apparatus, and (B) illustrates the operation of the plate cylinder of the rotary printing apparatus according to the third embodiment of the present invention. FIG. 3C is a schematic cross-sectional view for that, FIG. 3C is an enlarged cross-sectional view of the main part of the plate cylinder of FIG. 3B, and FIG. 3D is a rotary press according to the third embodiment of the present invention. It is an expanded sectional view of the principal part of the 1st modification of the plate cylinder of a printing device, and (E) is the 2nd modification of the plate cylinder of the rotary printing device according to the 3rd example of this invention. It is the expanded sectional view of the principal part of an example.

FIG. 3 is a schematic vertical sectional view of a plate cylinder of a rotary printing apparatus according to a fourth embodiment of the present invention.

[Explanation of symbols]

10, 10 ', 10''... Outer cylinder (plate cylinder body), 12a,
12b, 12'a, 12'b ... Side wall, 14a, 14b,
14'a, 14'b ... central shaft, 16a, 16b ... bearing,
18 ... Rotational force input gear, 20 ... Inner cylinder, 22 ... Penetration port (print plate suction means), 24 ... Suction tube (print plate suction means), 26 ...
Suction holes (plate adsorbing means), H, H '... plate, Ha, H'
a ... edge, S ... positioning slit, 30 ... positioning pin, 30a ... screw hole, 30b ... hexagonal hole, 32a ... through hole, 32b ... lid, 32c ... biasing means, 32f ... positioning pin selecting / moving means, 34a , 34b ... Conductive brush, 40
... Insulator, 42a, 42b ... Conductive brush.

Claims (8)

[Claims] 1. A plate cylinder main body having a cylindrical shape and having an outer peripheral surface around which a plate is wound; and a plate adsorbing means for adsorbing the plate to the outer peripheral surface of the plate cylinder main body. A plate cylinder for a rotary printing device. 2. A printing plate positioning means for positioning one end edge of the printing plate at a predetermined position on the outer peripheral surface is provided on the outer peripheral surface of the plate cylinder main body. The plate cylinder of the rotary printing apparatus described in 1. 3. The printing plate positioning means includes a positioning slit which is provided at a predetermined position on the outer peripheral surface of the plate cylinder main body and into which one edge portion of the printing plate is inserted and engaged. The plate cylinder of the rotary printing apparatus according to claim 2. 4. A positioning hole is formed at one edge of the printing plate, and the printing plate positioning means is provided at a predetermined position on the outer peripheral surface of the plate cylinder main body. The plate cylinder of the rotary printing apparatus according to claim 2, further comprising a positioning pin that is detachably attached to the plate cylinder. 5. The positioning pin of the printing plate positioning means is capable of projecting and retracting with respect to the outer peripheral surface of the plate cylinder main body, and the printing plate positioning means includes a biasing means for biasing the positioning pin toward the projecting position. The plate cylinder of the rotary printing apparatus according to claim 4, characterized in that. 6. The positioning pin of the printing plate positioning means is capable of projecting and retracting with respect to the outer peripheral surface of the plate cylinder main body, and the printing plate positioning means selectively positions the positioning pin between a protruding position and a retracted position. The plate cylinder of the rotary printing apparatus according to claim 4, further comprising a pin selection moving unit. 7. A printing plate suction means is provided in the plate cylinder main body and is connected to a suction hole opened to the outer peripheral surface of the plate cylinder main body, and communicated with an inner end of the suction hole inside the plate cylinder main body, and an outer peripheral surface of the plate cylinder main body. Negative pressure generating means for generating a negative pressure at the opening of the suction hole in the plate cylinder of the rotary printing apparatus according to any one of claims 1 to 6. 8. The plate according to claim 1, wherein the plate contains a magnetic material, and the plate attracting means contains an electromagnet for applying a magnetic force to the outer peripheral surface of the plate body. A plate cylinder of the rotary printing device according to any one of claims 1 to 4.