JPS6256147A - Inking apparatus of printing press - Google Patents

Abstract

PURPOSE:To enable printing so as to prevent the generation of ghost or to make ghost inconspicuous, by enhancing ink leveling effect by generating sliding on the surface of a ink form roller in the circumferential direction thereof in addition to the sliding of a vibrator roller in the axial direction thereof. CONSTITUTION:The gears of ink vibrator rollers 6, 7 rotationally driven through an ink cylinder 11 and an idler gear are constituted as transfer gears having different number of teeth and meshed with the idler gear. The vibrator rollers 6, 7 are forcibly driven at a peripheral speed different from that of the ink cylinder 11 and also rotate at a peripheral speed faster than that of a plate cylinder 1. Form rollers 2 to 5 are free rotary rollers and rotate with the friction forces between the ink vibrator rollers 6, 7 and the plate cylinder 1. The form rollers 2 to 5 are frictionally driven by both of the ink vibrator rollers 6, 7 having different peripheral speeds and the plate cylinder 1 and generate sliding with respect to the ink vibrator rollers 6, 7 and the plate cylinder 1.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an inking device that prevents the occurrence of ghosts in printing.

The conventional technical drawing shows an inking device of a conventional offset printing machine, especially an offset printing machine suitable for sheet-fed metal plate printing. The ink in the ink fountain is arranged as shown in the figure and is transferred onto a large number of rollers while being transferred to the plate cylinder 1 by four ink foam rollers 2.3.4.5.

Conventional offset printing machines with such ink supply devices produce solid images when printing solid screens with a large difference in printing width in the print width direction or repeat pattern screens with non-printing areas (blanks) in the solid screen. Density unevenness, that is, ghosting occurs on the screen.

This is because when the ink foam roller moves from one screen to the next when supplying ink to the printing plate, only the ink on the roller is sufficiently supplied and leveled.
Areas with high ink consumption are due to ink shortages, and areas with no ink consumption are due to surplus ink. This phenomenon is a problem that cannot be fundamentally avoided in current inking devices that supply ink to the plate cylinder using rollers.

Therefore, in the past, it was necessary to take into account the placement of the designs on the screen to create a layout that would prevent ghosts from appearing, or to print with opaque ink that has low density and good fluidity and prints with more 4&C to make ghosts less noticeable. There was no other way to deal with this problem.

Problems to be Solved by the Invention However, depending on the printed matter, there may be cases where the above-mentioned pattern layout is more likely to cause ghosting.

Especially when printing on sheet-fed all-corner boards for can manufacturing, #-j:,
In many cases, the layout that is most likely to cause ghosting is the multifaceted design of the combination of solids, text, and tone.

Even in the case of printing layouts where ghosts are likely to occur, the present invention uses a simple method to prevent ghosts from occurring or make ghosts less noticeable, without employing special printing methods using special ink. The object is to provide an inking device that can print.

Means to Solve the Problem The cause of ghosting is that, as mentioned above, the ink on the ink form roller is not leveled sufficiently, resulting in uneven ink film thickness on the roller, and this uneven ink film thickness is caused by the ink forming on the plate. It consists in being transferred to the cylinder.

Conventionally, IA FIII on an ink form roller.

This is mainly accomplished by sliding the vibrator roller in the axial direction, but the present invention improves the transmission mechanism of the conventional inking device so that in addition to the axial sliding of the vibrator roller, Furthermore, all of the above objects are achieved by generating slippage in the circumferential direction on the surface of the busy ink form roller to enhance the ink leveling effect.

The answer will be explained below using figures corresponding to the examples.

The present invention provides a partial or complete S of the ink foam rollers 2 to 5.
t, vibrator roller 6.7 and plate cylinder 7
It is constituted by making rotational contact with both or either one of them with a relative circumferential speed difference.

Working Vibrator roller 6.7 When forcedly driven at different circumferential speeds, inking roller 8.9, vibrator roller 6.
7. Differences in circumferential speeds, that is, slippage, occur on the rotating contact surfaces of the ink form rollers 2 to 5 and the plate cylinder 1, so that the ink is evenly leveled. Also, ink foam roller 2~5'? ,
When forcedly driven at a circumferential speed of M, the ink form roller
Sliding occurs more reliably on the rotating contact surfaces of the vibrator roller 6%7 and the plate cylinder 1, and it is also more effective in leveling the ink on the plate cylinder 1 surface.

In particular, at the circumferential speed of the first ink form roller 'ix,
When the plate is moved, in addition to leveling the ink, it also has the effect of removing dust on the printing plate.

Furthermore, by forcibly driving the vibrator roller 6.7 and the ink form rollers 2 to 5 at different circumferential speeds, it is possible to further reduce the noise caused by slipping on each rotating contact surface. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Below, embodiments of the present invention will be described in detail with reference to the drawings.

The figure shows an embodiment of the inking device of the present invention. In the figure, 1 is a plate cylinder, 2.3.4
．． 5 are first, second, third, and fourth ink foam rollers, 6.7.15.17 are ink vibrator rollers, 8.9.12.13.14.16 are inking rollers, and 11 is an ink foam roller. Cylinder, 18 is an inking roller, 1
9 is an ink 7 mountain roller.

These roller arrangements are similar to conventional inking devices.

The present invention eliminates the conventional rotary power transmission mechanism in the roller arrangement, and provides a relative circumferential speed difference between the ink foam roller and at least one of the vibrator roller and the plate cylinder that are in rotational contact with the ink foam roller. Rotate the next one, the loin Φ form roller, before d.
C. As a specific means of rotating with a relative circumferential speed difference, by forcibly driving the vibrator roller with a circumferential speed difference, the ink form roller indirectly rotates with a circumferential speed difference with the vibrator roller and plate cylinder. There are two possible methods: one in which the ink form roller is forcibly driven with a direct circumferential speed difference, and one in which both the vibrator roller and the ink form roller are forcibly driven with a direct circumferential speed difference.

First, an embodiment will be described in which a means for forcibly driving the vibrator roller with a circumferential speed cage is adopted.

In this embodiment, a vibrator roller 6 is rotated by transmission via an ink cylinder 11 and an idler gear (not shown).
．． The gear No. 7 is a transition gear having a different number of teeth, and meshes with the idler gear. As a result, the vibrator roller 6.7 is forcibly driven at a different circumferential speed than the ink cylinder 11. As a result, vibrator roller 6.7
rotates at a fast circumferential speed relative to the plate cylinder.

On the other hand, each of the ink foam rollers 2 to 5 is a freely rotating roller, and is rotated by the frictional force of the ink vibrator roller 6.7 and the plate cylinder 1. Therefore, each ink form roller 2 to 5 is frictionally driven by both the ink vibrator roller 6.7 and the plate cylinder 1, which have different circumferential speeds, and as a result, the ink vibrator roller 6.7 and the plate cylinder 1 have different circumferential speeds. Slippage occurs in both, causing them to rotate with a relative circumferential speed difference.

Therefore, in this embodiment, the inking roller 8.9
Circumferential slippage occurs at the contact surfaces of the ink vibrator roller 6.7, the ink vibrator roller 6.7 and the ink form rollers 2 to 5, and the ink form rollers 2 to 5 and the plate cylinder 1. Ink leveling can be done more effectively.

Note that the means for driving the ink vibrator rollers 6.7 with different circumferential speeds is not limited to the above embodiment, and for example, the ink vibrator rollers 6.7 can be driven with different circumferential speeds directly by motors without using a gear transmission mechanism. Various methods can be considered, such as rotating the However, in the above embodiment, all the ink form rollers rotated at different circumferential speeds, but for example, wX3. Pressure may be applied to rotate only the ink form roller aE4 with a difference in circumferential speed.

Next, a description will be given of an embodiment employing manual IRe in which the ink form roller is forcibly driven with a direct circumferential speed difference.

In this embodiment, only the first ink form roller 2 is
Instead of the freely rotating roller in the above embodiment, a gear is transmitted to the vibrator roller 6, and the circumferential speed of the vibrator roller 6 is changed to the gear of the ink form roller 2 in the not-illustrated gear mechanism. By employing such gears, the vibrator roller 6 and the plate cylinder 1 are forcibly driven to rotate with a difference in circumferential speed.

In this case, since the ink form roller 2 is forcibly driven, it is more likely that slippage will occur between the ink form roller 2 and the plate cylinder 1 than in the above embodiment, and the ink on the plate cylinder l will be evenly distributed. It can be done more effectively.

Furthermore, in the case of this embodiment, since slippage is forcibly generated on the contact surface between the first ink foam roller 2 and the plate cylinder 1, dust adhering to the plate surface of the plate cylinder 1 is actively removed during ink transfer. It should be noted that the first ink foam roller 2 in this embodiment is moved outside the image line of the printing plate, and also has the effect of removing dust on the printing plate.
The means for forcing the rotation with a difference in circumferential speed is not limited to the gear mechanism described above, and various means such as direct drive by a motor can be employed. In addition, in this embodiment, only the first ink foam roller was forced to rotate with a difference in circumferential speed, but in addition, only the last ink foam roller or all the ink foam rollers were forced to rotate with a difference in circumferential speed. You can also rotate it.

Finally, the two embodiments described above may be combined to forcibly drive both the vibrator roller and the ink foam roller at different circumferential speeds. In that case, the ink foam roller slips against the vibrator roller and plate cylinder, and the ink leveling can be done more effectively.
The ink foam roller also has the effect of removing dust from the plate surface.

In the above embodiment, only the first ink form roller may be forcibly driven with a difference in circumferential speed, and the second ink form roller may be forcibly driven at the same circumferential speed as the entire roller series.

Since the ink form roller in the conventional inking device eK is a roller that freely rotates due to friction, uneven rotation occurs due to the influence of recesses on the ink plate. Therefore, uneven transfer occurs in the ink foam transfer to the plate cylinder, causing uneven ink film thickness on the plate cylinder. Therefore, when the ink foam roller is forcibly driven as in the above embodiment, the ink foam roller always rotates uniformly, so that uneven ink transfer does not occur, and this has a positive effect on preventing the occurrence of ghosts.

Effects In the inking device of the present invention, the ink foam roller is in rotational contact with the plate cylinder and the vibrator roller with a relative speed difference, so that the rotational contact surface with the grate cylinder and the vibrator roller is Slippage occurs in the circumferential direction, and the ink can be leveled more evenly than with conventional methods. Therefore, even with a conventional design that tends to cause ghosts, it is possible to print while effectively preventing the ghosts from occurring.

Further, it can be easily implemented by improving a conventional inking device, and since it does not require a special printing method using special ink, it is possible to prevent the occurrence of ghosts without increasing printing costs.

Further, when the first ink form roller is forcibly driven with a difference in circumferential speed, in addition to the above-mentioned effects, there is also an effect of removing fine dust adhering to the plate surface of the plate cylinder.

As described above, the present invention has many advantages compared to conventional inking devices. It is something that you have.

[Brief explanation of drawings]

The drawing is a schematic diagram of the inking device of this embodiment. l nigerate cylinder 2.3.4.5: 1st % 2nd,
3rd and 4th ink foam rollers 6.7: Ink vibrator roller Patent applicant Toyo Seikan Co., Ltd. Applicant's agent Patent attorney Yoshifumi Sa (and 2 others)
given name)

Claims (1)

[Claims] 1) In an inking device of a printing press that supplies ink to a plate cylinder using a plurality of ink foam rollers, some or all of the ink foam rollers are brought into rotational contact with the ink foam rollers. 1. An inking device for a printing press, characterized in that the inking device is configured to be in rotational contact with at least one of a vibrator roller and a plate cylinder with a relative circumferential speed difference. 2) The inking device for a printing press according to claim 1, wherein the vibrator rollers are forcibly driven to rotate at different circumferential speeds. 3) The inking device for a printing press according to claim 1, wherein the ink foam rollers are forcibly driven to rotate at different circumferential speeds. 4) The inking device for a printing press according to claim 3, wherein the ink foam roller is a first ink foam roller. 5) The inking device for a printing press according to claim 1, wherein the ink foam roller and the vibrator roller are forcibly driven to rotate at different circumferential speeds.