JPH0342182B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cardboard printing machine that prints on sheets such as cardboard using ink.

Generally, in a flexo printing machine used for printing on cardboard sheets, an anilox roll and a rubber roll are in horizontal parallel contact, and ink reservoirs are formed in the valleys between the anilox roll and the rubber roll that are formed by this contact. There is a type in which the ink reservoir part always holds a predetermined amount of ink liquid. Therefore, in this type of printing press, both ends of the rubber roll are pressed against the anilox roll so that they are in parallel contact.
The contact pressure is different between the ends and the center, and as a result, the peripheral speed of the anilox roll is set a little faster than the rotation ratio of the rubber roll, so that the amount of ink liquid transferred to the printing cylinder is uniform. However, even with this method, there were problems such as the amount of ink liquid transferred to the printing cylinder, that is, unevenness occurred in the finished printing. For this reason, in order to prevent the above-mentioned problems, a so-called crowned rubber roll, in which the central part of the rubber roll is formed into a drum shape with a larger diameter than both ends, has been used in order to equalize the contact pressure. With the same crowned rubber roll, it is not possible to arbitrarily change the contact pressure depending on printing conditions, etc., and if you try to change the contact pressure, it will be difficult to obtain uniform contact pressure.
In particular, when the rubber roll wears out due to use, unevenness occurs in the contact pressure, but there are drawbacks such as the inability to make adjustments to correct this. On the other hand, similar problems have occurred in printing machines in which ink is transferred from a rubber roll immersed in ink in an ink tank to a printing cylinder via an anilox roll.

In view of the above circumstances, the present invention provides eccentric bearings at both ends of the rubber roll shaft, and by rotating the eccentric bearings in opposite left and right directions, the rubber roll comes into contact with the anilox roll while gradually increasing the angle of inclination. To provide a corrugated board printing machine which can easily and reliably adjust the contact pressure between an anilox roll and a rubber roll and adjust ink aperture by increasing the strength of the ink to make uniform line contact. It is.

The present invention will be described in detail below with reference to embodiments shown in the accompanying drawings. In FIG. 1, an anilox roll 1 is
The shaft 3 is supported by bearings 4a and 4b, respectively,
A gear 5 is fixed to the shaft 3, and a drive shaft 6 is attached to the gear 5.
The gears 7 are engaged with each other.

Further, the rubber roll 2 has a right end 8a of its shaft slidably fitted to an eccentric sprocket 10 supported by an eccentric bearing 9, and a sprocket 12 fixed to a drive shaft 11.
A chain 13 is stretched between the sprocket 10 and the sprocket 10. The shaft 8b at the left end of the rubber roll 2 is slidably fitted to an eccentric gear 14 supported by an eccentric bearing 17, and meshed with a gear 15 fixed to the drive shaft 11.

A sprocket 18 is fixed to the right end of the shaft 8a of the rubber roll 2, and a chain 21 is stretched between the sprockets 20 of the drive motor 19.

Next, to explain the operation, since the eccentric bearings 9 and 17 and the axes of the rubber roll 2 are offset by e, when the drive shaft 11 is rotated, the rotational force of the gear 15 and sprocket 12 is transferred to the eccentric sprocket 10 and the eccentric gear 14. rubber roll 2.
The shafts 8a and 8b move toward the anilox roll 1 side. As a result, the outer periphery of the rubber roll 2 comes into contact with the anilox roll 1. In this case, eccentric gear 1
4 and the eccentric sprocket 10 are rotating in the opposite direction, so the rubber roll 2 comes into contact with the anilox roll 1 at a predetermined angle as shown in FIG.
The rubber roll 2 is brought into line contact with the anilox roll 1. The contact of the rubber roll 2 with the anilox roll 1 in that case, in other words, the movement of the rubber roll 2 at -, -, - in FIG. 1 is shown in FIG.

The rubber roll 2 is always kept at a constant angle with respect to the anilox roll 1 as shown in FIG.
It is also possible to obtain uniform line contact by moving the rubber roll 2 parallel to the anilox roll 1 and increasing contact with the anilox roll 1 while maintaining a constant angle.

Next, in order to print on the printing material 22, as shown in FIG.
As shown in FIG. 6, the printing material 22 is passed between a printing cylinder 24 having a printing plate 23 attached to its outer periphery and a press roll 25 at a rate of one sheet per rotation of the printing cylinder 24. Therefore, printing is performed using the printing material 22 as before.

The printing cylinder 24 is given a rotational force by a drive shaft (not shown) (known in the art), the anilox roll 1 is given a rotational force by the rotational force of a drive shaft 6, and the rubber roll 2 is given a rotational force by a drive motor 19. Rotational force is given. Incidentally, the printing cylinder 24, the anilox roll 1, and the rubber roll 2 often have the same circumferential speed.

As described above, according to the present invention, the rubber roll 2 is brought into contact with the anilox roll 1 while increasing the inclination angle, that is, the rubber roll 2 is brought into contact with the anilox roll 1 while being inclined at a predetermined angle.
Since this is a corrugated board printing machine in which line contact is made between the anilox roll 1 and the rubber roll 2, the contact pressure between the anilox roll 1 and the rubber roll 2 can be easily and reliably adjusted, and therefore, the ink aperture can be freely adjusted and ink spots can be prevented.

Furthermore, in the conventional type in which a crown is formed on the rubber roll 2 and brought into contact with the anilox roll 1, if the crown wears out during use, ink spots will occur, so the rubber roll 2 must be replaced. In the present invention, by changing the inclination angle of the rubber roll 2 with respect to the anilox roll 1, the rubber roll 2 can be brought into line contact with the anilox roll 1 with uniform contact pressure.

Furthermore, since the rubber roll 2 is inclined with respect to the anilox roll 1, ink can be recovered quickly. Therefore, setup time for cleaning the rolls, etc. can be shortened.

[Brief explanation of drawings]

Fig. 1 is a plan view showing an overview of the present invention, Fig. 2 is a perspective view of an anilox roll and a rubber roll, and Fig. 3 is a perspective view of an anilox roll and a rubber roll.
The figure is an explanatory diagram showing the rubber roll in contact with the anilox roll at a predetermined angle, Figure 4 is an explanatory diagram showing the state shown in Figure 3, and Figures 5 and 6 show the main parts of a cardboard printing machine. FIG. 1...Anilox roll, 2...Rubber roll.

Claims (1)

[Scope of Claims] 1. In a cardboard printing machine in which a rubber roll can be freely moved toward and away from an anilox roll, the anilox roll can be moved by sliding both sides of the shaft of the rubber roll onto eccentric bearings and by rotating both eccentric bearings in the opposite direction. A corrugated board printing machine characterized by making line contact with a rubber roll while being inclined at a predetermined angle to equalize contact pressure in the axial direction.