JPH0380430B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sheet-fed printing press, and in particular, in a single-sided/double-sided printing machine that uses a double-diameter intermediate cylinder as a paper conveyance means, two sets of pawl devices provided on the double-diameter intermediate cylinder are used. A and B doubles caused by paper delivery errors in each of the above are eliminated by a stretching adjustment member that is provided near the outer periphery of the double-diameter intermediate cylinder so that the amount of protrusion can be adjusted. The present invention relates to a sheet expansion adjustment device that prevents this by correcting the position of the trailing edge.

Single-sided/double-sided printing sheet-fed printing machines print two or more multicolors on one side of the paper, or one or more colors on both the front and back sides of the paper, and can be used in a wide range of applications. , has received great acclaim. In this dual-purpose printing press, each plate cylinder,
A plurality of printing units each having a blanket cylinder, an impression cylinder, an inking device, etc. are linked by a paper transport means called a double-diameter intermediate cylinder system. In other words, the upstream printing unit is transported by a paper conveyance means consisting of a paper transfer cylinder with the same diameter as the impression cylinder, an intermediate cylinder with a double diameter (hereinafter referred to as the double cylinder), and a reversing cylinder with the same diameter as the impression cylinder. and a downstream printing unit for paper transport and paper reversal required for duplex printing.

For this reason, the double cylinder has a leading edge gripper that grips the leading edge of the paper, and a trailing edge gripper that presses the trailing edge of the paper and spreads and stretches it only during duplex printing. The two sets are arranged facing each other with a 180° phase shift around the main axis of the double barrel. By the way, these two sets of claw devices have one set as A claw and the other as B claw.
Commonly known as nails.

In the case of single-sided printing, a paper transfer cylinder receives the leading edge of the sheet from the upstream printing unit and passes the leading edge to the leading edge gripper of the double cylinder. The leading edge gripper of the folding cylinder passes the leading edge intact to the gripper of the reversing cylinder at the point of contact with the following reversing cylinder. The grippers on the reversing cylinder then feed the leading edge of the paper to the downstream printing unit, resulting in successive printing on one side of the paper. Note that during this single-sided printing, the trailing edge gripper of the double cylinder does not play any active role and is virtually at rest.

In the case of double-sided printing, trailing edge grippers play an important role, unlike in the case of single-sided printing. To explain this, the paper transfer cylinder receives the leading edge of the sheet from the upstream printing unit and grips it with the leading edge grippers of the double cylinder, as in the case of simplex printing, but then the trailing edge gripper It also operates to press down on the trailing edge of the paper, applying expansion and stretching action to the trailing edge in order to tightly wrap the paper around the outer periphery of the double barrel. The reason for this is that in the case of double-sided printing, the trailing edge of the sheet serves as a reference for delivery to the reversing cylinder.
That is, the leading edge gripper passes through the opposite contact point with the reversing cylinder while holding the sheet, and then, when the trailing edge gripper reaches the opposite contact point, it hands over the trailing edge of the sheet to the reversing gripper of the reversing cylinder. As the reversing cylinder rotates, the sheet is turned upside down and delivered to the downstream printing unit, where printing is performed on the side of the sheet opposite to the side printed by the upstream printing unit.

By the way, when examining the print quality obtained by the above-mentioned dual-purpose printing press, a printing failure called double printing may occur. What is this tabli?
This refers to the phenomenon in which the printing lines of the same plate are misaligned and printed twice or triply, and is a printing disorder that is particularly unique when a double-diameter intermediate cylinder system is used as the paper conveyance means.
There is something called "A/B double".

To explain this phenomenon, the mounting positions of the two sets of claw devices (one pair of leading edge grippers and trailing edge grippers are referred to as A claws and the other pair are referred to as B claws as already mentioned) provided on the double barrel. is 180° in the circumferential direction of the double barrel.
It must be divided properly.
In addition, the radius from the center of the double barrel main shaft to the two sets of pawl devices must also be exactly the same for each pawl device. However, if these requirements are not met and there are assembly errors, processing errors, etc. in the A jaws and B jaws, the paper gripped by these A jaws or B jaws will be misregistered, and this Because, A
A transfer error occurs between the paper passed by the claw and the paper passed by the B claw, and as a result, the direction of the duplication differs for each sheet of paper, causing the A.
B double will occur.

In particular, in the case of double-sided printing, unlike the case of single-sided printing where only the leading edge of the paper is simply transferred sequentially, the trailing edge of the paper becomes the reference for passing from the double cylinder to the reversing cylinder. If the holding position of the trailing edge of the paper is shifted in each case, significant A/B duplication will occur. In double-sided printing, the trailing edge of the paper is held by a trailing edge gripper that can move in the circumferential direction of the double cylinder according to the length of the paper, and expands and unfolds in the circumferential and axial directions of the double cylinder. It is stretched and wrapped tightly around the outside. In other words, there must be no deviation in the radius of the two sets of claw devices from the main axis of the double barrel, and if the trailing edge positions of the A claw and B claw are even slightly shifted, paper transfer will be interrupted. Because the standards are different, there are many A/B duplicates.

As a technique for preventing double A and B, Japanese Patent Publication No. 57-1425 proposes that the sheet support segment on which the gripper is provided is supported by a shaft via a sliding ring, A device is disclosed in which play is provided between the sliding ring and the ring, and the play is changed by deforming the sliding ring using an adjustment screw to make necessary adjustments.

However, this prior art has the disadvantage that, first, the adjustment work is extremely difficult. In other words, it is necessary to measure minute adjustments on the order of 1/100 mm while adjusting each of the numerous support segments, and such adjustment work is practically only possible for skilled mechanical assemblers. Therefore, it is impossible for an operator to easily perform printing operations. Second, the sustainability of the adjustment effect is highly questionable. In other words, even if the sliding ring can be successfully deformed, the effect of the painstaking adjustment cannot be expected to last in a printing press that rotates continuously at high speed. The third drawback is that it cannot respond to changes in the specifications of the paper used.
In other words, there are a wide variety of paper to be printed on, from fluttery thin paper to stiff thick paper, but since the adjustment work itself is difficult, the final holding position of the trailing edge is set using the A claw and B claw depending on the specifications and properties of the paper. It is not possible to fine-tune each of them.

The present invention has been made in view of the above-mentioned problems, and provides an advanced paper expansion adjustment device.The purpose of the present invention is to enable adjustment work to be performed easily and to ensure a continuous adjustment effect. , to enable immediate adjustment to paper specifications.

For this purpose, in the expansion adjustment device according to the present invention, the expansion adjustment member, a portion of which adjustably protrudes from the circumferential surface of the double barrel, is provided between the pair of leading edge grippers and trailing edge grippers. It is provided. especially,
In a preferred embodiment of the present invention, the expansion adjustment member is an eccentric bar shaped like an arc, and extends over the entire axial width of the double barrel in the immediate vicinity of the leading edge gripper.

This allows the A claw to adjust the trailing edge position of the paper that is held and positioned by the leading edge gripper and trailing edge gripper and wrapped around the circumference of the double cylinder during double-sided printing.
Fine adjustment is made for each of the B claws to prevent delivery errors at the trailing edge and to eliminate A and B duplication.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a side view of a double drum equipped with a paper stretching and stretching adjustment device according to the present invention, FIG. 2 is a partially cutaway plan view of the double drum shown in FIG. 1, and FIG. FIG. 4 is a partially cutaway plan view of the double drum shown in FIG. 3, and FIG. 5 is a side view for explaining the operation of the apparatus of the present invention.

In a sheet-fed printing machine capable of single-sided printing/double-sided printing, especially in the case of double-sided printing, the trailing edge of the sheet is used as a reference for transfer when reversing the sheet. Such paper transfer is performed by linking the upstream printing unit and the downstream printing unit by a paper transport means consisting of a paper transfer cylinder, a double cylinder, and a reversing cylinder.

The doubler cylinder shown in FIG. 1 has twice the diameter of the impression cylinder and is therefore rotated once for every two revolutions of the impression cylinder.
Two pairs of pawl devices, A pawl and B pawl, are provided facing each other with a phase shift of 180 degrees around the main shaft 1. Constituting the pawl device are a leading edge gripper 2 and a trailing edge gripper 3, of which the leading edge gripper 2 is provided on the fixed support segment 4 and the trailing edge gripper 3 is provided on the movable support segment 5. The fixed support segment 4 and the movable support segment 5 are
A large number of them are gathered around the main shaft 1 in a comb-like shape to form the circumferential surface of the double barrel.

The fixed support segment 4 on which the leading edge gripper 2 is provided is a comb-tooth skeleton structure that is fixedly arranged on the main shaft 1, through which a cam-controlled gripper shaft 6 passes, and in which a claw portion is provided. It has a receiving part 8 which is a counterpart of 7.

On the other hand, the trailing edge gripper 3 is provided on a movable support segment 5 which is a comb-like skeleton structure. The movable support segments 5 are rotatable about the main shaft 1 and are located behind the fixed support segments 4 with respect to the direction of rotation of the double drum indicated by the arrow, and are sandwiched in a staggered manner. The reason why the movable support segment 5 is able to rotate around the main shaft 1 is that in double-sided printing, the position of the trailing edge gripper 3 relative to the leading edge gripper 2 is adjusted according to the length of the paper to be printed. Because it has to change. Furthermore, the unique role of the trailing edge gripper 3 is not to simply grip the trailing edge of the paper, but to expand and stretch the paper in the circumferential and axial directions of the double barrel so that the paper fits tightly against the outer periphery of the double barrel. You have to make sure that it wraps around you. Therefore, the trailing edge gripper 3 is
It is composed of a swingable swing receiving part 9 and a presser claw 10, and these swing receiving part 9 and presser claw 10 are controlled by operating shafts 11 and 12, respectively. There is.

Assuming the configuration as described above, the aim of the present invention is that during double-sided printing, the trailing edge of the paper is used as the reference for transfer, and the trailing edge position is 1/100 between the A claw and B claw.
There is a slight deviation on the order of mm, and this is supported by A and B.
The purpose is to prevent doubles from occurring. As mentioned above, the paper is gripped by a pair of leading edge grippers 2.
and the trailing edge gripper 3, and is wrapped tightly around the circumferential surface of the double barrel, which is constituted by a number of fixed support segments 4 and movable support segments 5. At this time, the position of the leading edge of the paper is
constant throughout both cases of duplex printing (of course,
Misalignment of the leading edge grippers 2 in the A and B jaws also causes A and B duplication, but the present invention does not actively concern this point. ) Therefore, in order to finely adjust the trailing edge position for each of the A claw and B claw under these conditions, it is sufficient to change the circumference of the double cylinder around which the paper is wound.

In the paper expansion adjustment device according to the present invention, a rigid expansion adjustment member 13 is provided to slightly change the winding path length of the paper on the circumferential surface of the double barrel. A portion of the extension adjustment member 13 protrudes in an adjustable manner from the circumferential surface of the doubling barrel constituted by the fixed support segment 4 and the movable support segment 5.
and the trailing edge gripper 3. However, the protrusion here is of a very small value, and of course the protrusion does not come into contact with the adjacent paper transfer cylinder or reversing cylinder.

In particular, this extension adjustment member 13 is provided immediately behind the leading edge gripper 2 with respect to the direction of rotation of the double barrel indicated by the arrow. The reason for selecting such a position is firstly from the design consideration of the fixed support segment 4 and the movable support segment 5, which have a skeleton structure. The expansion adjustment member 1 is located in the area of the fixed support segment 4 where it may enter, that is, near the rear end of the fixed support segment 4.
This is because 3 cannot be placed. The second reason is that by providing the stretching adjustment member 13 in the immediate vicinity of the leading edge gripper 2 that reliably and firmly presses the leading edge of the paper, the position of the trailing edge of the paper can be finely adjusted reliably and clearly. This is because it can be adjusted.

The extension adjustment member 13 also has an arc-shaped cross-sectional outer periphery at least at a portion that actually protrudes or may protrude from the circumferential surface of the double barrel. This is to prevent the paper from being damaged and to make the change in the winding path length by the expansion adjustment member 13 gentle.

Furthermore, the expansion adjustment member 13 spans the entire axial width of the double barrel, as best shown in FIG. By extending the entire width of the paper, it is possible to uniformly adjust the entire width of the paper.
The protrusion amount adjustment work can be performed. In addition, instead of individually adjusting a large number of fixed support segments 4, one expansion adjustment member 1
3 allows you to make adjustments all at once and uniformly.

Regarding the cross-sectional shape of the extension adjustment member 13, it is easily understood that an elliptical bar can fulfill the function. However, elliptical bars are generally difficult to work with and expensive.

Therefore, as shown in an enlarged view in FIG. 3, it is preferable to use an eccentric arc-shaped bar. Here, the eccentric arc-shaped bar refers to the main body 1 of the extension adjustment member 13.
4 has a circular cross-sectional shape, but the center of the main body 14 and the center of the shaft supports 15 at both ends are eccentric, and this means that the support members 17 attached to the shoulders 16 on both sides of the double barrel are eccentric. Axial support 15
can be rotated to change the amount of protrusion of the main body 14 of the expansion adjustment member 13.

The shaft supports 15 at both ends of the expansion adjustment member 13 are supported by support members 17 fixed to the shoulders 16 with mounting bolts 18 . For example, the amount of protrusion of the extension adjustment member 13 can also be changed by forming a large mounting hole for the support member 17 and attaching the support member 17 itself by slightly moving it with respect to the shoulder portion 16. Further, one of the pair of left and right support members 17 may be made movable.

As shown in FIG. 3, the support member 17 has a slot 19, and the shaft support 15 is tightened and fixed with a tightening bolt 20. The tightening bolt 20 is loosened when rotating and adjusting the portion 21 with a tool. In order to make it easier to understand the degree of protrusion of the expansion adjustment member 13, the support member 17 may be provided with a scale 21.

How the actual amount of protrusion changes with respect to the rotation angle of the extension adjustment member 13 can be easily measured and is merely a matter of design.

In FIG. 5, the paper 23 is actually wound around the double cylinder in the circumferential direction. Of course, the two sheets of paper 23 do not remain wrapped at the same time during actual printing operations, but the drawings are merely drawn to assist in understanding the apparatus of the present invention.
The leading edge gripper 2 strongly presses the leading edge of the paper 23, and the trailing edge gripper 3 spreads and stretches the trailing edge of the paper 23. Therefore, the stretching adjusting device according to the present invention It is clearly understood that when the winding path length of the paper 23 is finely adjusted for each of the A claw and the B claw, the position of the trailing edge of the paper 23 is also finely adjusted. This eliminates the error in delivering the paper 23 due to each of the A claw and B claw, and
The device of the present invention prevents duplication.

What should be noted about the device of the present invention is that the structure itself is very simple, and in the extreme, only one eccentric bar and its supporting member are required. Further, since the adjustment work is simply rotating the eccentric bar, it is very easy and can be done in a short time even by an operator who is not familiar with the machine. Furthermore, since there are no components that are dependent on continuous high-speed operation of the printing press, the adjustment effect is not impaired over time. In addition, switching adjustments can be made immediately in response to various properties such as the strength of the paper to be printed. Further, even if the machining accuracy of the fixed support segment and the rotary support segment that support the pawl device is reduced, the paper delivery accuracy can be ensured by the apparatus of the present invention.

[Brief explanation of drawings]

FIG. 1 is a side view of a double drum equipped with a paper stretching and stretching adjustment device according to the present invention, FIG. 2 is a partially cutaway plan view of the double drum shown in FIG. 1, and FIG. FIG. 4 is a partially cutaway plan view of the double drum shown in FIG. 3, and FIG. 5 is a side view for explaining the operation of the apparatus of the present invention. DESCRIPTION OF SYMBOLS 1... Main shaft, 2... Leading edge gripper, 3... Trailing edge gripper, 4... Fixed support segment, 5... Movable support segment, 13... Extension adjustment member, 14
...Body, 15...Axis support, 16...Shoulder, 17
...Supporting member, 18...Mounting bolt, 19...Slot, 20...Tightening bolt, 21...Head, 2
2...Scale, 23...Scale.

Claims (1)

[Scope of Claims] 1. A single-sided printing/double-sided printing sheet-fed printing machine in which a plurality of printing units are linked by a sheet conveying means including a double-diameter intermediate cylinder, wherein the double-diameter intermediate cylinder has one
Two pairs of pawl devices, consisting of a pair of leading edge grippers and a trailing edge gripper, are provided opposite to each other around the main shaft, of which the leading edge gripper is mounted on a fixed support segment fixedly arranged on the main shaft, and The gripper is provided on a movable support segment that can rotate in the circumferential direction around the main shaft, and a portion of the gripper can be adjusted from the circumferential surface of the double-diameter intermediate barrel constituted by the fixed support segment and the movable support segment. 1. A paper expansion adjustment device for a sheet-fed printing press, characterized in that an expansion adjustment member projecting from above is provided between a pair of leading edge gripper and trailing edge gripper. 2. The paper spreading adjustment device according to claim 1, characterized in that the spreading adjusting member is provided immediately behind the leading edge gripper with respect to the rotational direction of the double diameter intermediate cylinder. 3. The sheet expansion adjustment device according to claim 2, characterized in that the cross-sectional outer periphery of the projectable portion of the expansion adjustment member is arcuate. 4. The paper expansion adjustment device according to claim 3, characterized in that the expansion adjustment member spans the entire width of the double-diameter intermediate cylinder in the axial direction. 5. The paper expansion adjustment device according to claim 4, wherein the expansion adjustment member is a bar having an elliptical cross section. 6. The paper expansion adjustment device according to claim 4, characterized in that the expansion adjustment member is an eccentric arc-shaped bar. 7. The paper expansion adjustment device according to claim 5 or 6, characterized in that the support members at both ends of the expansion adjustment member are movable.