JPH0318586B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a sheet-fed offset printing machine in which printing paper is discharged by a chain delivery device.
The present invention relates to a printing paper delivery mechanism with an improved paper ejection claw stand and printing surface receiving section attached to a chain delivery device.

First, a conventional sheet-fed offset printing machine will be explained according to FIGS. 1 to 6. As shown in FIG.
passes through the paper feed device 2 to the swing gripper 3
It is passed to the impression cylinder claw 5 of the impression cylinder 4, and is fed by the impression cylinder 4. Then, an inking device 7 disposed above the plate cylinder 6 applies ink to a plate 8 attached to the circumferential surface of the plate cylinder 6, and the ink on this plate 8 is applied to the circumferential surface of the plate cylinder 9. As shown in FIG. 2, the printing paper P is transferred onto the blanket 10 wound around the blanket 10, and as described above, is conveyed over the impression cylinder 4 by the impression cylinder claw 5 by the clamping pressure of the blanket cylinder 9 and the impression cylinder 4. Printing is performed as follows. Further, the printing paper P is passed to the paper ejection claw 14 on the paper ejection chain 13 which is rotated by the chain wheel 12 attached to the paper ejection shaft 11, and is sent in the running direction of the paper ejection claw 14 and is ejected. The paper is discharged onto the paper tray 15.

The speed at which the paper ejection claw 14 on the paper ejection chain 13 transfers the paper is equal to the circumferential speed of the impression cylinder 4, but the outer periphery of the impression cylinder 4 between the chain wheels 12 that receives the printing paper P is As a surface receiving part, it had the following structure in order to prevent dirt. That is, as shown in FIG. 3, shaft mounting flanges 16 are fixed to both sides of the paper discharge shaft 11, and a plurality of feed wheel mounting shafts 17 installed between the shaft mounting flanges 16 each have a plurality of feed wheels mounted thereon. A car 18 is attached. Note that there is a slight space between the paper discharge claw 14 and the feed wheel 18 adjacent thereto to prevent mutual interference.

Now, during printing, when the printing paper P is passed to the paper ejection claw 14 as shown in FIG. Since there is no guide between the cylinders 18 and 18, the printing paper P is linear in this part, so that the amount of feeding of the printing paper P is smaller than that in the outer peripheral part of the impression cylinder 4. This difference appears as a phenomenon in which the printed surface of the printing paper P is pulled by the blank cylinder 9 due to the strong tack of ink, creating a gap as shown by S in FIG. Due to this phenomenon, the printing paper P is always sent in waves as the paper ejection claw 14 and feed wheel 18 rotate, and these waves create thin striped patterns in solid printing and halftone dot printing, which are used as shot marks in offset printing. It was a serious flaw. On the other hand, since there is also a space between each of the feed wheels 18 attached to each feed wheel attachment shaft 17, the printing paper P becomes slack in this area and becomes wavy in the horizontal direction, resulting in the same defect as in the case described above. .
Further, in the conventional device shown in FIG. 5, a plurality of feed plates 19 are fixed to the paper ejection shaft 11 instead of each of the feed wheels 18 described above, but in this case as well, the same defects as in the device described above occur.

In order to eliminate the above defects, as shown in FIG. 6, the diameter of the impression cylinder 4 is increased and after the printing paper P is completely printed, the printing paper P is delivered to the paper ejection claw 14. ing. However, since the impression cylinder 4 is large, two impression cylinder claws 5 are required, and unevenness between the two impression cylinder claws 5 tends to cause differences in printing, and the machine also becomes larger and more expensive. There is.

The present invention has been made in order to eliminate the above-mentioned defects, and its purpose is to prevent the printing paper from being pulled toward the printing cylinder and waving due to the tack of ink, and to prevent the above-mentioned shocks in solid printing and halftone printing. It is an object of the present invention to provide a chain delivery and transfer mechanism for printing paper in an offset printing machine, which can eliminate blind spots and prevent the printing paper from being bent due to ink tack.

Hereinafter, one embodiment of the present invention will be explained according to FIGS. 7 to 11. As shown in FIG. A cylinder 20 is attached, and as shown in FIG. 7, an arcuate printing paper receiving surface 21 is formed on its outer periphery. The radius of this printing paper receiving surface 21 and the radius of the outer peripheral surface of the impression cylinder 4 are formed to be the same, and the printing paper receiving surface 21 is covered with glass piece paper 22 (which may be sandpaper) to prevent stains. is pasted.

Further, a plurality of paper ejection claws 14 are attached to a paper ejection claw stand 23 attached between both paper ejection chains 13, and a paper receiving portion 24 is provided in a protruding manner corresponding to each paper ejection claw 14. This paper receiving portion 24 has an arcuate guide surface 2 having the same radius as the printing paper receiving surface 21.
4a is formed. Glass piece paper 22 is also pasted on this guide surface 24a. On the other hand, the printing surface receiving cylinder 20 is formed with a notch 25 into which the paper receiving portion 24 is fitted. Further, a plurality of feed wheel mounting shafts 17 are installed at predetermined intervals in the circumferential direction between shaft mounting flanges 16 that are attached to the printing surface receiving cylinder 20 and fixed on both sides of the paper discharge shaft 11.
A plurality of feed wheels 18 are attached and fixed to each feed wheel attachment shaft 17 (see FIG. 3). A feed dog 18a is engraved on the outer periphery of the feed wheel 18, and is arranged on the same circumference as the printing paper receiving surface 21.

Next, the operation of the printing paper delivery mechanism described above will be explained. As the chain wheel 12 rotates, the paper discharge claw 14 receives the printing paper P from the outer periphery of the impression cylinder 4. At this time, as the paper ejection shaft 11 rotates, the printing surface receiving cylinder 20 also rotates, and the paper receiving part 24 fits into the notch 25 thereof as shown in FIG. This cutout portion 25 prevents the print surface receiving cylinder 20 and the paper receiving portion 24 from colliding. In this state, the guide surface 24a of the paper receiving portion 24 is continuous with the printing paper receiving surface 21 on the same circumference as the printing paper receiving surface 21. Accordingly, the printing paper P performs a complete circular motion along the guide surface 24a and the printing paper receiving surface 21 as the paper ejection claw base 23 and the printing surface receiving cylinder 20 rotate, as shown in FIG.
This circular movement continues until printing by the blank cylinder 9 and the impression cylinder 4 is completed. At this time, the glass piece paper 22 prevents the printing surface from becoming dirty. and,
Following this circular movement, the printing paper P is moved by the feed wheel 18.
Sent by. When the paper discharge claw base 23 is further rotated, the paper receiving portion 24 is separated from the cutout portion 25 of the printing surface receiving cylinder 20, as shown in FIG. 11, and the printing paper P is sent onto the paper discharge base 15. . At this time, since the printing paper P is removed from the printing surface receiving cylinder 20, it does not stick to it and roll up, allowing smooth paper feeding, which is suitable for high-speed operation.

Note that the arc size of the printing paper receiving surface 21 of the printing surface receiving cylinder 20 needs to be at least the size obtained by subtracting the paper feeding dimension of the outer periphery of the impression cylinder 4 from the maximum length of the printing paper P in the feeding direction.

The present invention described in detail above is applicable to a chain delivery device that discharges printing paper P to be printed onto a paper discharge table 15 by being clamped between the blank cylinder 9 to which ink is transferred and the impression cylinder 4. Paper ejection shaft 1 corresponding to 4
1 is attached with a printing surface receiving cylinder 20 having an arcuate printing paper receiving surface 21 on the outer periphery, and a feed wheel 18 is mounted so that the feeding dog 18a is arranged on the same circumference as this printing paper receiving surface 21. death,
Further, the paper ejection claw base 23 attached to the paper ejection chain 13 has the printing paper receiving surface 2 from the time when the paper ejection claw 14 receives the outer circumferential printing paper P from the impression cylinder 4.
The present invention is characterized in that a guide surface 24a is formed which is continuous with the receiving surface 21 on the same circumference and rotates together with the receiving surface 21 at a predetermined angle. Therefore, during printing, the printing paper P rests on the guide surface 24a of the paper ejection claw base 23 and the printing paper receiving surface 21 of the printing surface receiving cylinder 20, and is ejected without vertical and horizontal undulations, completely preventing scratches in offset printing. There is an effect that can be done. Furthermore, it is also possible to prevent the printing paper P from being pulled toward the blank cylinder 9 and being bent by the strong tack of the ink. Further, after printing is completed, the printing paper P is sent by the anti-stain feeder 18, so when the paper ejection claw 14 moves away from the printing surface receiving cylinder 20, the printing paper P does not adhere to the printing surface receiving cylinder 20. The printing paper P can be stably discharged under high-speed operation without being rolled up.

It should be noted that the present invention can also be applied to all types of sheet-fed offset printing machines, such as single color, two color, and four color.

[Brief explanation of drawings]

1 to 6 show conventional examples, FIG. 1 is a side view showing the schematic structure of a sheet-fed offset printing machine, FIG. 2 is a partially enlarged view showing the printing paper delivery mechanism of the chain delivery device, and FIG. The figure is a perspective view, and Figure 4 is a partially enlarged view showing the waving phenomenon of printing paper.
5 and 6 are a perspective view and a partially enlarged view, respectively, showing another conventional example of a printing paper delivery mechanism of a chain delivery device. 7 to 11 show embodiments of the present invention, FIG. 7 is a partially enlarged view showing the printing paper delivery mechanism of the chain delivery device, and FIG. 8 is a portion showing the printing surface receiving cylinder and paper ejection claw stand. An enlarged perspective view, FIG. 9 is a partial enlarged view showing a state in which the printing paper receiving surface of the printing surface receiving cylinder and the guide surface of the paper ejection claw base are combined, and FIG. 10 is a portion showing the printing paper transfer operation during printing. The enlarged view, FIG. 11, is a partially enlarged view showing the discharge operation of the printing paper after printing is completed. Impression cylinder...4, Impression cylinder claw...5, Plate cylinder...6, Blank cylinder...9, Paper ejection shaft...11, Chain wheel...1
2, Paper ejection chain...13, Paper ejection claw...14, Feed wheel...18, Feed dog...18a, Printing surface receiving cylinder...20, Printing paper receiving surface...21, Glass piece paper...22 , paper ejection claw stand...23,
Guide surface...24a, cutout...25, printing paper...P.

Claims (1)

[Claims] 1. The printing paper P to be printed by being clamped between the blank cylinder 9 and the impression cylinder 4 to which the ink is transferred is placed on the paper discharge tray 1.
In the chain delivery device that discharges the paper onto the paper discharge shaft 11 corresponding to the impression cylinder 4, a printing paper receiving cylinder 20 having an arcuate printing paper receiving surface 21 on the outer periphery is attached to the printing paper receiving cylinder 20, and this printing paper receiving surface 21 The feed wheel 18 is mounted so that the feed dog 18a is arranged on the same circumference as
A guide surface 24a is formed which is continuous with the receiving surface 21 on the same circumference as the printing paper receiving surface 21 from the time of receiving the printing paper P on the outer periphery of the impression cylinder 4 and rotates together with the receiving surface 21 at a predetermined angle. A printing paper delivery mechanism of a chain delivery device in an offset printing machine, characterized by: 2 The printing surface receiving cylinder 20 has a paper ejection claw stand 23.
A printing paper delivery mechanism of a chain delivery device in an offset printing press according to claim 1, wherein a notch 25 is formed in which the guide surface 24a of the printing paper receiving surface 21 is fitted so as to be continuous with the printing paper receiving surface 21. 3. A printing paper delivery mechanism of a chain delivery device in an offset printing press according to claim 1, wherein the radius of the printing paper receiving surface 21 and the radius of the outer peripheral surface of the impression cylinder 4 are the same. 4. A printing paper delivery mechanism of a chain delivery device in an offset printing press according to claim 1, wherein a glass piece paper 22 is attached to the printing paper receiving surface 21 and the guide surface 24a.