JPH0321346B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a double-sided multicolor offset printing machine, which can perform four-color offset printing on both the front and back sides of a sheet by passing it once. It is related to a printing machine that is capable of printing.

[Conventional technology]

A double-sided offset printing machine is used to perform offset printing on both the front and back sides of a sheet in one pass of the printing press. Conventionally, there are various types of double-sided printing machines of this kind, and the following are known as representative ones.

That is, there are those that can be printed in multiple colors on the front side and single color on the back side, those that can be printed in single color on both the front and back, and those that can be printed in multiple colors on both the front and back sides. Some of these machines include (a) those that are originally designed as double-sided printing machines, and (b) those that are normally used as single-sided multicolor printing machines, but can be converted to double-sided printing machines as needed. There are (c) double-sided multicolor printing machines with configurations other than those described above that can be used.

For the former, that is, (a), as an example, there is
-There is one published in Publication No. 86801. The publication contains 1
There have been disclosed devices that can perform printing in two colors on the front side and one color on the back side and those that can perform monochrome printing on the front and both sides at the same time. These are the so-called B-B type, and one of the two rubber cylinders is equipped with a paper gripping claw, and the paper sheet is held in the grip of this rubber cylinder claw. When passing between blanket cylinders, printing is performed on both sides at the same time. If such a B-B type is used to print four colors on both sides of a sheet of paper, a large number of intermediate cylinders will be required between the printing units, and the machine will inevitably become larger. Incidentally, as disclosed in the above-mentioned publication, in the case where two-color printing can be performed on the surface, a separately provided single-color printing unit is connected to the above-mentioned B-B via three intermediate cylinders.
It is connected to a type printing unit.

Next, (b) considering how a normal multi-color offset printing machine can be converted into a double-sided printing machine,
This type of printing press is often found in so-called tandem multicolor printing presses in which a monochromatic printing unit consisting of three cylinders, a plate cylinder, a blanket cylinder, and an impression cylinder, is connected by an intermediate cylinder.

A tandem printing machine that can also be used for double-sided printing usually has three intermediate cylinders between the printing units. This intermediate cylinder is equipped with a sheet reversing device, and can be converted into a double-sided printing machine by switching operations. In this case, the front side of the sheet is first printed as usual in the front-stage printing unit for surface printing, but this sheet is sent to the rear-stage printing unit via the intermediate cylinder equipped with the reversing device. When the sheet is turned, the sheet is turned over by the action of the turning device so that the trailing edge of the sheet now leads.
Therefore, the rear side of the sheet is printed in the subsequent printing unit.

Tokukokoku No. 52-97802,
Some of these are described in Japanese Patent Publication No. 52-138211, Japanese Patent Publication No. 79607-1979, Japanese Patent Publication No. 149404-1984, etc. As can be seen in the above-mentioned publication, all of the reversing devices have complicated mechanisms, and the adjustment at the time of switching is complicated, and the complexity increases as the size of the sheet to be printed changes, and at the same time, it is difficult to print. Mechanical limitations have also been added to the sheet size, and the machines have to become larger.

Next, we will discuss what is disclosed in Japanese Patent Publication No. 58-147364.

A second embodiment of the above-mentioned publication discloses a cylinder arrangement structure of a double-sided four-color printing offset printing machine that can perform four-color printing on both sides in one pass of a sheet. The device according to this embodiment is considered to fall within the range of the above-mentioned B-B type, but it is characterized by not using an intermediate cylinder between the printing units, and it is recognized that it can be made more compact.

However, in order to omit the intermediate cylinder, a configuration was adopted in which all blanket cylinders were provided with gripping claws to transport the sheets, and until the end of double-sided, four-color printing, the paper sheets were transferred on the blanket cylinders. It is supposed to be changed eight times (the last rubber body has no claws, but is instead held in place by a chain gripper). Therefore, it can be said that the influence on registration accuracy is still large.

Although there is no mention of cylinder release in the same publication, as can be seen at a glance from the cylinder arrangement shown in the drawing, there is no room to separate the blanket cylinders for cylinder release, which is essential for printing presses, and the direction of the plate cylinder is If cylinder relief is to be carried out, it is thought that the plate cylinder associated with the inking mechanism must be relieved. Therefore, there is no doubt that this barrel arrangement complicates the barrel release mechanism.

[Problem that the invention seeks to solve]

The present invention was proposed under the above circumstances.
This is a printing machine that can perform offset printing in each of four colors on both sides of a sheet in a single pass without reversing the paper, and at the same time, the number of times the paper is gripped during printing is reduced compared to conventional machines, making it compact and easy to operate. Improving sex. Furthermore, instead of the B-B type configuration, we aim to provide at a low price a cylinder arrangement in which printing is performed between an impression cylinder (a cylinder that does not need to be covered with a blanket) and a transfer cylinder (a rubber cylinder). It is.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention forms a printing section with a cylinder arrangement without an intermediate cylinder, and the sheets fed by the paper feeder are arranged so that the sheets are fed from the bottom to the top.
In other words, it is designed to be compact by being configured to be transported vertically.

That is, four sets of five-cylinder printing units are provided, each consisting of two plate cylinders and two blanket cylinders with the same diameter, and one common impression cylinder with three times the diameter of these cylinders. The five-cylinder printing unit is constructed by arranging the plate cylinders and blanket cylinders side by side, and arranging them in two stages, upper and lower, with a gap between them, and an impression cylinder is connected to both the upper and lower blanket cylinders. The four sets of five-cylinder printing units are configured such that the direction in which the two upper and lower rubber cylinders connect with respect to the impression cylinder is opposite to the left and right. Those in a relational arrangement that looks like this are called “opposite hands” or “opposite hands”). In the above-mentioned opposite-hand printing unit, the impression cylinders are connected alternately and in such a way that the straight line connecting the axes of the impression cylinders forms a zigzag shape in the vertical direction, and the printing unit as a whole is capable of four-color double-sided printing. Configure. The impression cylinder located at the lowermost part of the printing section is connected to a paper feeder for supplying sheets, and the uppermost impression cylinder is connected to a paper ejecting apparatus.

[Effect]

According to the above configuration, since the impression cylinders are connected to each other in a zigzag shape in the vertical direction, the sheet fed to the lowermost impression cylinder gripping claw is transferred to each printing press as the printing press rotates. The paper passes through the unit, is sequentially transferred upward, and is ejected to a paper ejection device. Transfer of sheets between units is carried out by the grippers of the impression cylinders. The bottom printing unit first prints two colors on the front side of the sheet, the next unit prints two colors on the back side, and the third unit above prints two more colors on the front side, making a total of four colors. Printing is done, and in the final unit, two colors are added to the back side, thus completing a four-color print on both sides. During this period, the sheet is gripped by the impression cylinder gripper four times.

〔Example〕

The accompanying drawings are schematic side views showing essential parts of the present invention, and show one embodiment thereof.

In the drawings, the number 1 indicates 8 plate cylinders, 2
shows eight rubber cylinders, respectively. The plate cylinder 1 and the blanket cylinder 2 have the same diameter. Two pairs of the plate cylinder 1 and the blanket cylinder 2 are arranged horizontally to form one set. 3 indicates four impression cylinders. Each impression cylinder is provided with gripping claws (not shown) at three equal positions on the circumference. The two pairs of plate cylinders and blanket cylinders are arranged at intervals, and the impression cylinder 3 is connected to them as a common impression cylinder, and these five cylinders constitute a two-color printing unit. There are four sets of the above-mentioned printing units A, B, C, and D. Printing unit A and printing unit C have printing cylinder 1 and impression cylinder 3 of blanket cylinder 2.
The arrangement is on the left side and is in the same manner. Furthermore, printing unit B and printing unit D have their plate cylinder 1 and blanket cylinder 2 on the right side of the impression cylinder 3,
Although the structure is similar to that of the above embodiment, it is placed in opposite directions. As clearly shown in the drawing, each of the different printing units is arranged alternately, and three impression cylinders are connected in a zigzag pattern and combined into one unit, forming a printing section cylinder arrangement for double-sided, four-color printing. has been done.

E is an example of a paper feeding device and has the following configuration. 4 is a well-known sheet feeder, and 5 is a sheet stacked in the feeder. 6 schematically shows a well-known swing gripper mechanism. This swing gripper 6
is for delivering the sheet fed by the feeder 4 and stopped on the paper feed plate 7 to the rotating paper feed cylinder 8 while making a reciprocating circular arc movement. 9, 10, 11
1 schematically shows a known chain conveyance mechanism in the same manner as above, in which a sheet of paper held by a gripping claw of the paper feed cylinder 8 (not shown) is held at a contact point with the paper feed cylinder 8.
It is configured so that it is gripped by gripping claws (not shown) attached to the chain and accurately delivered to the impression cylinder 3 at the lowest position in the printing section. In addition, the above 9.1
0 indicates a sprocket for driving the chain 11 formed to have twice the diameter of the plate cylinder.

F schematically represents a paper discharge device, which is a well-known chain delivery device. 12 is a chain equipped with a well-known gripping claw (not shown);
3 is the sprocket. Further, numeral 14 indicates printed sheets which are discharged by the paper discharge device F and are piled up.

Since the present invention has the above-described configuration, the sheet is supplied to the impression cylinder 3 at the lowest position in the printing section by the paper feeder E, and from the impression cylinder follows the path shown by the bold line in the direction of the arrow. The sheet is gripped by gripping claws (not shown) on the impression cylinder, transported upward, and sent to the sheet discharge device F. While the sheet follows this path, it is printed in four colors on both sides. That is, when a sheet of paper held by a gripping claw (not shown) of impression cylinder 3 of printing unit A passes between two rubber bands 2, 2, an image is printed in two colors on the surface of the sheet from the rubber cylinder. be done. Then, the sheet that is taken from printing unit A to the impression cylinder 3 of the next printing unit B is
This time, the printing surface is turned over so that it is in contact with the peripheral surface of the impression cylinder 3, and two-color printing is performed on the back surface in the same manner as described above. When the sheet that has passed between the printing units in this way is grabbed by the unillustrated gripping claws of the chain 12 of the paper delivery device F, each of the four colors is printed on both the front and back sides of the sheet. It will be administered.

To explain the configuration of the present invention shown in the attached drawings using more specific numbers, the size of the sheet to be printed is, for example, 469 mm x 636 mm.
When performing this on relatively small sets of size (about 2 mm), the cylinder diameter can be relatively small, so even if the impression cylinders are stacked vertically,
Coupled with the zigzag arrangement, it is convenient because it can be accommodated at a height that does not interfere with normal company buildings. By the way, when we are targeting Kikuhankiban, we will temporarily set the diameter of the printing cylinder and rubber cylinder to 200mm.
Suppose that it is set to φ. Then, as shown in the attached drawing, the angle (body angle) α formed by the plate, rubber, and pressure cylinder is
If the distance between the centers of each plate cylinder is set to be around 142°, and the distance between the centers of each plate cylinder is set to be the same, the total height of the machine including the bed can be kept at around 2.6m, making it suitable for use even in small factory buildings. It can be provided as a compact device. In addition, when using the above configuration, the distance between the circumferential surfaces of the plate cylinders is approximately 30 cm, so
It will not interfere with your work.

Next, I would like to add about the mechanism for attaching and detaching the torso (so-called torso release).As in the previous example, the diameter of the torso is 200 mm.
When φ, the wrapping angle (the angle formed when the end of the arc when a 469 mm long paper is wrapped around the circumferential surface of the cylinder and the center of the cylinder) is approximately 270°. becomes. As in this example, when the winding angle is large and the body angle is as large as 142°, "body release" uses multiple eccentric bearings to support the rubber cylinder, and each eccentric bearing is rotated at a predetermined timing. The rubber cylinder can be attached and detached from the printing cylinder and the impression cylinder individually.
There is no risk of producing waste paper.
(See Publication No. 9054).

The embodiments have been described in detail above, but the present invention is not limited to the barrel diameter of the above-mentioned embodiments, and the diameter of the barrel can be arbitrarily selected, and the target printing paper size is also limited to the chrysanthemum size. It's not something that should be done.

In addition, in the part indicated by the two-dot chain line in the figure,
15 is the frame of the printing press body. Reference numeral 16 denotes an inking frame in which an inking section (not shown) is installed. Further, a dampening water device is installed below each plate cylinder, but is not shown. Further, 18 indicates a paper feed frame, 19 a bed, 20 a delivery frame, etc.

[Other Examples]

Next, other embodiments of the present invention will be described, but since they can be easily understood, they will not be particularly illustrated using the accompanying drawings. In the embodiment shown in the accompanying drawings, the vertical center-to-center distances a, b, and c of each impression cylinder 3 are formed at equal intervals, and the center-to-center distance of each plate cylinder on both the left side and the right side shown in the figure, and,
Although the rubber cylinders are shown arranged so that the distance between their centers is the same, this is preferable because the eccentric bearing of the rubber cylinder and various other members can be used as a common member. However, the present invention is not limited to this. Taking the distances e and f between the plate cylinder centers on the side indicated by L in the figure as an example, the distance between the plate cylinder centers f and each printing unit will be explained. The distance e between the plate cylinder centers formed between them does not necessarily have to be the same, and the distance between the blanket cylinders may be somewhat wider than the distance between the plate cylinders, that is, the cylinder angle may be formed smaller than that of the example. .

〔Effect of the invention〕

Since the present invention does not use an intermediate cylinder and is composed of four impression cylinders, even when performing four-color double-sided printing, the number of times the printing paper is gripped by the gripping claws of the cylinder is only four times, compared to the known example described above. It is effective in improving registration accuracy. Moreover, since the supplied sheets are transported from the bottom to the top, they can be provided very compactly. Furthermore, since the configurations of the four sets of five-cylinder printing units are the same, parts can be shared and the cost can be reduced. In addition, since the impression cylinders are connected in a zigzag manner, it is preferable that there is a large amount of time until the sheet being printed is printed on the next sheet.

Also, unlike the B-B type double-sided printing machine, printing is not done between blankets, but between the plates, so to speak.
Since it is a three-cylinder type consisting of rubber and pressure, it is possible to print sharply with less blur compared to the B-B type.

[Brief explanation of the drawing]

The accompanying drawing is a schematic side view of a four-color sheet-fed offset printing press according to the present invention, and shows one embodiment thereof. 1... Plate cylinder, 2... Rubber cylinder, 3... Impression cylinder, A,
B...Five-cylinder printing unit in the same manner, C, D
...A five-cylinder printing unit with the right and left hands of the above A and B being different.

Claims (1)

[Claims] 1 Two pairs of plate cylinders and rubber cylinders of equal diameter arranged side by side are arranged in two stages, upper and lower, with an interval between them, and an impression cylinder having a diameter three times that of these cylinders and equipped with a gripping claw is attached to both the upper and lower rubber cylinders. A five-cylinder type sheet-fed two-color printing unit in which cylinders are connected as a common impression cylinder, and the printing cylinder and the blanket cylinder are arranged so that the relative positions of the plate cylinder and the blanket cylinder with respect to the impression cylinder are opposite to each other. Two sets of each printing unit are provided, and a cylinder arrangement structure is constructed in which the above-mentioned reverse printing units are arranged alternately in the vertical direction and the impression cylinders are connected so that a straight line connecting the axis of the impression cylinders forms a zigzag shape. The impression cylinder located at the lowermost position is connected to a paper feeding device for feeding sheets, and the uppermost impression cylinder is connected to a paper ejecting device. Double-sided 4-color offset printing machine.