JPH08142311A - Ink device for printing machine - Google Patents

Abstract

PURPOSE: To provide an ink device having a simple structure capable of completely preventing ghosts from appearing on a printed matter. CONSTITUTION: An outer peripheral lower part of an anilox roll 12 having fine recesses on its whole surface is dipped into an ink in an ink fountain 11. A doctor blade 14 is made to come into contact with the outer periphery of the anilox roll 12 so as to scrape off excessive ink. An ink attach roll 13 to be in contact with the anilox roll 12 and a plate cylinder 1 has the same diameter as that of the plate cylinder 1. A plate attached to the outer periphery of the plate cylinder 1 is made to come into contact with the outer periphery of the ink attach roll 13 always at a fixed position. A fixed quantity of ink is supplied to the contact position from the anilox roll 12 so as to prevent generation of ghosts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inking device for a printing machine.

[0002]

2. Description of the Related Art The inking unit of a rotary printing press for label printing, which continuously prints an ink image on a continuous paper running in one direction, usually dips the lower part of the outer circumference of an ink supply roller in the ink of an ink fountain. Then, the ink film adhering to the outer circumference of the ink supply roller is transferred to the inking roll via a roll group consisting of a plurality of rollers, and the ink of the inking roll is supplied to the plate surface on the plate cylinder.

Here, the roll group of the inking device has a structure in which metal rolls and rubber rolls are alternately arranged because troubles such as baking occur when the metal rolls are brought into contact with each other.

In order to reduce the size of the inking unit, it is preferable to reduce the number of rolls in the roll group, but if the number of rolls is reduced, a ghost is likely to occur on the printed matter.

Here, the ghost means that the densities of the ink layers of the same color are not uniform.

[0006]

Conventionally, in order to prevent the above-mentioned ghost from appearing on the printed matter, the number of rolls of the roll group in the inking device is increased, but it has not been completely eliminated.

Further, by increasing the number of rolls in the roll group, it takes a lot of time to adjust the pressure between the rolls and to wash the rolls at the time of color exchange, resulting in an increase in the number of steps required for processing and assembling, resulting in an increase in cost. there were.

Further, since the rubber roll is treated as a consumable item, there is a disadvantage that the maintenance cost is high.

An object of the present invention is to provide an extremely simple inking device which can completely prevent the appearance of ghosts on printed matter.

[0010]

In order to solve the above-mentioned problems, the first technical means is to immerse the lower part of the outer periphery of an anilox roll having microscopic depressions on the entire surface in the ink of the ink fountain, and to make the anilox roll. A doctor blade for scraping ink is brought into contact with the outer periphery of the plate, and an inking roll for supplying the ink of the anilox roll to the plate attached to the plate cylinder is provided between the anilox roll and the plate cylinder. The diameter is an integral multiple of the outer diameter of the plate cylinder.

In order to solve the above-mentioned problems, a second technical means is to use an ink in an ink fountain in an inking device of a printing machine provided with a plate cylinder having a maximum printing length of 1/2 of a circumferential length. Dip the lower part of the anilox roll having microscopic depressions on the entire surface, contact the doctor blade for ink scraping with the anilox roll, and contact the anilox roll with the plate cylinder to transfer the ink of the anilox roll to the plate cylinder. The outer diameter of the inking roll supplied to the upper plate is 1/2 of the outer diameter of the plate cylinder.

[0012]

As described above, by using the anilox roll, the ink held in the fine depressions of the roll can be supplied to the inking roll, so that the ink can be supplied in a fixed amount to the inking roll. it can.

The outer diameter of the inking roll is an integral multiple or 1/2 of the outer diameter of the plate cylinder, so that the contact position between the plate surface of the plate cylinder and the inking roll is always constant. Since a fixed amount of ink is supplied from the anilox roll to the ink transfer portion of the inking roll, it is possible to completely prevent ghosts from appearing on the printed matter.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a three-cylinder type offset printing machine for transferring the ink image of the plate cylinder 1 to the blanket cylinder 2 and printing the ink image on the printing paper A supplied between the ink cylinder 3 and the impression cylinder 3. Show.

Inking device 10 for supplying ink to the plate cylinder 1.
Has an ink fountain 11, an anilox roll 12 whose lower outer periphery is immersed in the ink of the ink fountain 11, and an inking roll 13 that rotates in contact with each of the anilox roll 12 and the plate cylinder 1.

The anilox roll 12 has microscopic depressions 12a on the entire surface, and the doctor blade 1 is provided on the outer periphery thereof.
4 is pressed. The doctor blade 14 serves to scrape off excess ink adhering to the outer periphery of the anilox roll 12.

The inking roll 13 has the same diameter as the plate cylinder 1, and is rotated in the opposite direction at the same speed as the peripheral speed of the plate cylinder 1 by a gear interlocking mechanism or the like.

Now, when the printing press is driven, the anilox roll 12, the inking roll 13, the plate cylinder 1, the blanket cylinder 2 and the impression cylinder 3 rotate in the directions indicated by the arrows.

By the rotation of the anilox roll 12, the ink adheres to the outer periphery of the anilox roll 12, and the excess ink is scraped off by the doctor blade 14.

Therefore, a fixed amount of ink is supplied to the inking roll 13, and the ink is transferred to the plate B mounted on the outer periphery of the plate cylinder 1. The ink adhering to the plate surface of the plate cylinder 1 is transferred to the blanket cylinder 2 and printed on the printing paper A supplied between it and the impression cylinder 3.

In the above printing state, since the plate cylinder 1 and the inking roll 13 have the same diameter and rotate at the same peripheral speed, the plate of the plate cylinder 1 and the inking roll 13 are always It will come into contact at a fixed position.

Therefore, from the inking roll 13 to the plate cylinder 1
Since the ink supply portion supplied to the plate surface of the plate is always constant and the ink is supplied in a fixed amount from the anilox roll 12 to the ink supply portion, a uniform amount of ink is always transferred onto the plate surface of the plate cylinder 1. Will be. For this reason,
It is possible to perform good printing on a printed matter without generating a ghost.

In the embodiment shown in FIG. 1, the plate cylinder 1 and the inking roll 13 have the same diameter, but the outer diameter of the inking roll 13 may be an integral multiple of 2 or more of the outer diameter of the plate cylinder 1. . Also in this case, only the number of contact positions of the plate surface of the plate cylinder 1 with respect to the outer circumference of the inking roll 13 increases, and the contact positions do not shift in the circumferential direction, and the ink is quantitatively supplied from the anilox roll 12 to the contact positions. As a result, it is possible to prevent the occurrence of ghost.

FIG. 2 shows another embodiment of the present invention. This embodiment, like the previous embodiment, shows a three-cylinder type offset printing machine comprising a plate cylinder 1, a blanket cylinder 2 and an impression cylinder 3, which enables printing of various feed sizes without replacing the plate cylinder 1. As much as possible, the maximum printing length of the plate cylinder 1 is set to 1/2 of the circumferential length of the plate cylinder 1, and the remaining half of the printing paper A is stopped or moved back. I have to.

The inking device for supplying ink to the plate surface of the plate cylinder 1 has an anilox roll 12 and an inking roll 13, and the outer diameter of the inking roll 13 is 1/2 of the outer diameter of the plate cylinder 1. Has been done.

As described above, by making the outer diameter of the inking roll 13 half the outer diameter of the plate cylinder 1, the contact position of the plate B on the plate cylinder 1 with respect to the outer circumference of the inking roll 13 is always. Since a fixed amount of ink is supplied from the anilox roll 12 to the contact position, it is possible to completely prevent the generation of ghost.

In the above-described embodiment, the inking roll 13 can be half the outer diameter of the plate cylinder 1, so that the inking device can be made compact.

[0029]

As described above, in the inking device according to the present invention, the outer diameter of the inking roll for supplying ink onto the plate surface of the plate cylinder is set to an integral multiple of the outer diameter of the plate cylinder. Since the contact position of the plate surface with respect to the outer circumference of the plate is always fixed and ink is supplied in a fixed amount from the contact position to the contact position, it is possible to completely prevent ghosts from being generated on the printed matter.

Further, since the anilox roll and the inking roll have a simple structure with a small number of rolls, the inking device can be downsized and the inking device can be easily cleaned by changing the ink.

Furthermore, in a printing machine in which the maximum printing length is ½ the circumference of the plate cylinder, the inking device can be operated by setting the outer diameter of the inking roll to half the outer diameter of the plate cylinder. The size can be further reduced.

[Brief description of drawings]

FIG. 1 is a schematic view showing a first embodiment of an inking device according to the present invention.

FIG. 2 is a schematic view showing a second embodiment of the same inking device.

[Explanation of symbols]

 1 plate cylinder 11 ink fountain 12 anilox roll 13 inking roll 14 doctor blade

Claims (2)

[Claims] 1. A lower part of the outer periphery of an anilox roll having fine depressions on the entire surface is dipped in the ink of an ink fountain, and a doctor blade for scraping ink is brought into contact with the outer periphery of the anilox roll to form the anilox roll and the plate cylinder. Between the ink and the anilox roll ink is provided to the plate mounted on the plate cylinder, an inking roll is provided, and the outer diameter of the inking roll is set to an integral multiple of the outer diameter of the plate cylinder. Inking device. 2. In an inking unit of a printing machine equipped with a plate cylinder having a maximum printing length of ½ of the circumferential length, the lower part of an anilox roll having fine depressions on the entire surface is immersed in the ink of the ink fountain. Then, the doctor blade for ink scraping is brought into contact with the anilox roll to contact the anilox roll and the plate cylinder to supply the ink of the anilox roll to the plate on the plate cylinder. The inking device of a printing press, which is ½ of the outer diameter of.