JPS62191146A - Printing press - Google Patents

Abstract

PURPOSE:To make the printing of a large pattern with plural pieces of plate cylinders of a small diameter possible, by a method wherein a plate cylinder and a press roll are cyclically rotated with variable speed, the printing is carried out when the speeds of paper feeding and that of the plate cylinder coincide with each other only while a plate draft comes in contact with the paper and further, plural pieces of printing units which print the same color are provided. CONSTITUTION:The printing units A and B of the same specification of which to the plate cylinder 2, 2 of the same diameter the plate drafts 3, 3 of the same pattern of a length L1 are respectively attached, are provided. In order to print the same pattern, the printing units A and B are alternately used. As of the motion curve of the cyclic motion in variable speed of the plate cylinders 2 of printing units A and B, though the solid line V1 is an ideal motion curve, it becomes a motion curve V2 because of the presence of the acceleration time of the plate cylinder. The motion curves of A and B are the same. Because one printing unit can be preferably printed alternately, the state apparently becomes the same one as the case where the margin of (L1+2l) exists and its motion speed does not remarkably differ from the speed V of a web sheet. When the speed of the web sheet is V, the speed during that time becomes VL2/(L1+2l). Even if l is made small, the variation amount of speed is limited without increasing by determining L1 and L2 suitably.

Description

[Detailed description of the invention] [Industrial application field] TECHNICAL FIELD The present invention relates to a general arbitrary plate long rotary press.

[Conventional technology]

In conventional rotary presses such as lychee printing machines, the sheet running speed is constant and the single plate cylinder is also operated at a constant rotation speed, and when printing a pattern of arbitrary length, the entire single plate cylinder must be replaced. There is.

Therefore, when printing patterns of various sizes depending on the size of the cardboard box, such as printing on liner paper for cardboard boxes, it is necessary to replace not only the printing plate but also the printing cylinder depending on the printing length. be.

[Problem that the invention seeks to solve]

As mentioned above, in conventional equipment, the printing plate and printing cylinder are replaced depending on the printing length, so there is a problem in that it is necessary to prepare a large number of expensive printing cylinders, and it takes a lot of time to change printing cylinders. .

As a method to solve the above problem, a method can be considered in which only the printing plate is replaced without replacing the first printing cylinder, and the printing cylinder is rotated at a periodically variable speed while the printing material is fed at a constant speed.

However, if this method uses only one printing unit for printing one color, the amount of speed change in the operation curve of the periodic speed change operation of the plate cylinder of the printing unit becomes too large. There are practical problems. This situation will be explained using a diagram.

FIG. 9 shows printed w knits, but in contrast to FIG. 1.

1 is a printing material such as a web sheet, 2 is a printing cylinder, 3 is a replaceable printing plate, 4 is a press roll, and 5 is an ink roll.

FIG. 10 shows the dimensional relationship between the plate cylinder 2 and the plate 3.

FIG. 11 shows the intended printed matter. As shown in Figure 11, L□ is the length of the manuscript, and l is the margin. Generally, when printing on a web sheet, the margin! should be as small as possible.

When trying to print as shown in Fig. 11, the plate cylinder 2 shown in Fig. 9
of.

A front rotational movement must be performed as shown in FIG. 12.

In Figure n, ■ is the speed of the web sheet 1 running at a constant speed.

As shown in the figure, during printing, the rotation speed of the first plate cylinder is made to match the speed V of the web sheet. If the value is extremely large during the margin l, problems arise such as in practice, rotation with such rapid acceleration and deceleration is impossible.

[Means for solving problems]

In a printing machine that prints patterns, characters, etc. on a web-shaped printing material that runs at a constant speed over an arbitrary length range determined by the length of the plate, (a) the rotating circumferential surface of multiple plate cylinders; A printing plate of arbitrary length and length is attached to the top of the printing plate so as to be exchangeable, and the material to be printed is pressed between the printing plate and the press roll to perform printing.

(b) Rotating the plate cylinder and press roll periodically at variable speeds,
The speeds of one paper and the plate cylinder are matched only while the plate is in contact with the paper.

(c) A plurality of printing units that print the same color are provided.

[Effect]

Since the same color can be printed using a plurality of plate cylinders having relatively small diameters, the rotational speed of the plate cylinders, that is, the printing speed can be increased.

Printing in which each plate cylinder has the same pattern and each plate cylinder is used alternately,
Alternatively, it becomes possible to print a large picture by dividing it into individual plate cylinders and printing with a plurality of plate cylinders into one large picture as a whole.

〔Example〕

FIG. 1 shows the configuration of a printing unit according to the present invention. As shown in FIG. 2
A and B are provided. Figure 2 shows the relationship between the printing plate 3 and the printing cylinder 2 director.

FIG. 3 shows a printed matter printed by a printing machine according to the present invention, and l is a margin.

As shown in FIG. 3, printing units A and B are used alternately to print the same pattern. At this time, the operation curve of the periodic speed change operation of the printing cylinders 2 of printing units A and B is as shown in FIG. Solid line v1 in Figure 4
is an ideal operating curve, but in reality there is an acceleration/deceleration time for the first plate cylinder, so the operating curve is as shown in v2. The operating curves in FIG. 4 are exactly the same for A and B.

In this operation curve, since one printing unit only needs to print one by one, the apparent margin is (L1+2j)
It is the same thing that the driving speed during this period is
The web sheet speed V and the width are not very different. Even if the web sheet speed V is made small, there is an advantage that if Ll and B2 are set appropriately, the amount of change in speed can be large and take a long time.

Other embodiments are shown in FIGS. 5 to 8. in this case,
By using the two printing units A and B, it is possible to print a pattern whose printed length L is larger than the individual circumference length L1+L2 or L3+L4. Normally, with one printing roll, it is impossible to print a pattern longer than the length of the printing roll. However, as shown in FIG. 6 of the present invention, two printing units of the same color are provided, and A L□ on the side, B3 on B@
Paste up the length of the paper, and alternately
, B prints, overall L = L1+
It becomes possible to print large L3 designs.

The operation curve of the printing unit on the A side in this case is shown in FIG. 8, but in this case as well, as in FIG.
, L3, the speed slam will be within a sufficiently practically possible range. In addition, the feature of this method is that it is possible to print large designs,
Since this can be achieved with a relatively small diameter plate cylinder, the rotational moment of inertia of the first plate cylinder can be reduced.

In the case of a plate cylinder that periodically rotates at variable speeds like the printing press of the present invention, there are advantages such as the ability to reduce motor power.

In addition, such operation curves and rotation control of the first plate cylinder can be achieved using recent microcomputer technology and servo motor technology.
It is easily achievable.

〔Effect of the invention〕

For one-color printing, two or more printing units are installed, and one large printing plate is divided into two or more parts depending on the length of one printing plate, and each piece is attached to the printing cylinder. Large designs can be printed on multiple plate cylinders of relatively small diameter with practically possible operating curves, or by attaching the same or different plates to all plate cylinders. It has become possible to print the same or different designs with small margins and with a practically possible operating curve.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a printing press of the present invention in which the same plate is attached to two rolls A and B. Figure 2 shows the relationship between the length of the plate and the circumference of the plate cylinder. FIG. 3 shows an example of printed matter produced by the printing machine of the present invention. FIG. 4 is an operating curve for periodic variable speed rotation of a plate cylinder according to the invention. FIG. 5 is a block diagram of the printing press of the present invention when printing a pattern that is longer than the circumference of the plate cylinder. FIG. 6 shows the length of the printing presses attached to the two printing units. FIG. 7 shows an example of printed matter produced by the printing unit shown in FIG. 6. FIG. 8 is an operating curve of the printing unit on the A side of FIG. 6. FIG. 9 is a configuration diagram of a conventional one-color, one-unit case. FIG. 10 shows the dimensional relationship between the printing cylinder and the printing plate, and FIG. 11 shows the intended printed material. FIG. 12 shows the operating curve of the conventional device. 1... Printing material web sheet, 2... Plate cylinder, 3...
・Print version. 4... Press roll, 5... Ink supply roll. Sub-Agent Patent Attorney Shige Okamoto 2 people outside of the text Figure 1 1--Ichiro ■Sword printing plate Web sheet 2-m-Print cylinder 3--Print 4--Brace roll 5--Inkey common supply mouth Niru 8 1～゛

Claims (1)

[Claims] In a printing machine that prints patterns, characters, etc. on a web-like printing member that runs at a constant speed in an arbitrary length range determined by the length of a printing plate, A printing plate of arbitrary length is attached to the rotating circumferential surface so as to be exchangeable, the material to be printed is sandwiched between the printing plate and the press roll, and the plate cylinder and press roll are rotated at variable speeds periodically, so that the printing plate is A printing machine that performs printing by matching the speed of the paper and the plate cylinder only while they are in contact with the paper, and further comprising a plurality of printing units that print the same color.