JPH07102700B2 - Inking device - Google Patents

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, and more particularly, it has two rollers which are in proximity to or in contact with each other, and which removes excess ink on the peripheral surface of the roller on the downstream side. The inking device.

[0002]

2. Description of the Related Art An inking device having two rollers which are in close proximity to or in contact with each other and which removes excess ink on the peripheral surface of the roller on the downstream side is, for example, Shoukai Sho 58-48438.
The one disclosed in the publication "Offset Printing Machine" is known.

As shown in FIG. 5, this inking device includes an ink fountain roller FR which is immersed in the ink stored in the ink fountain IF and is rotated at a relatively low peripheral speed by immersing a part of the peripheral surface of the ink fountain roller FR. FR
Close to the ink fountain roller FR on the downstream side of
The ink fountain roller FR has an ink metering roller MR that rotates at a faster peripheral speed, and a doctor blade DB that comes into contact with the peripheral surface of the ink metering roller MR on the downstream side in the rotational direction than the vicinity of the ink fountain roller FR. .

Ink fountain roller FR
The ink attached to the peripheral surface of the ink fountain roller FR is rotated by the rotation of the ink fountain roller FR.
And is transferred to the peripheral surface of the ink metering roller MR, reaches the position of the doctor blade DB by the rotation of the ink metering roller MR, and the excess is removed. Ink remaining on the peripheral surface of the ink metering roller MR that has passed the position where the doctor blade DB abuts,
It is designed to be supplied to the printing plate that is the supply destination.

In such an inking device, the amount of ink brought to the proximity portion α between the ink fountain roller FR and the ink metering roller MR by the rotation of the ink fountain roller FR is transferred to the peripheral surface of the ink metering roller MR. So that the amount of ink carried away from the proximity part α due to its rotation is larger,
Set the number of revolutions of the ink fountain roller FR,
The ink supplied to the printing plate is kept short.
Therefore, the ink brought to the proximity portion α by the rotation of the ink fountain roller FR gradually increases to the space A which is gradually narrowed toward the proximity portion α on the upstream side in the rotation direction of the ink fountain roller FR of the proximity portion α. While collecting.

[0006]

However, the ink accumulated in the space A suddenly bursts due to some kind of momentum, and the ink fountain roller FR and the ink metering roller MR.
When the amount of ink that has passed is large and a large load acts on the doctor blade DB in a shocking manner, ink metering is performed. In some cases, the excessive amount of ink on the peripheral surface of the roller MR was insufficiently removed, causing a temporary excess in the amount of ink supplied to the plate surface. In addition, there is a limit to the amount of ink that can be accumulated in the space A, and when the amount of ink exceeds the limit, the ink that has accumulated in the space A will be swirled all around its peripheral surface against the rotation of the ink fountain roller FR. It may slip off and the transfer of ink to the peripheral surface of the ink metering roller MR may become insufficient, causing a temporary shortage in the amount of ink supplied to the plate surface.

In any case, the print quality is deteriorated by causing unnecessary shading on the printing surface.

On the other hand, when this conventional inking device is used for lithographic printing using dampening water, the dampening water that has entered the ink supply path from the plate surface gradually increases while accumulating with the ink in the space A, The water content of the ink is increased to decrease the printing density, and further the ink acceptability of the peripheral surfaces of the ink fountain roller FR and the ink metering roller MR is significantly deteriorated, and the ink is spread on the peripheral surfaces of these rollers FR and MR. In some cases, so-called roller stripping, which does not adhere or transfer, was generated, and the ink could not be supplied to the printing plate.

The present invention has been made in view of these problems, and is provided in a proximity portion or a contact portion upstream of a proximity portion or a contact portion of two rollers that are close to or in contact with each other, in an upstream side in a rotation direction of the roller. It is an object of the present invention to prevent ink or the like having a predetermined amount or more from accumulating in a space that is gradually narrowed toward the end so that a high-quality printed surface can be continuously and stably obtained.

[0010]

According to the present invention, two rollers, namely, a downstream roller and an upstream roller rotating at a peripheral speed lower than the downstream roller are brought into close proximity or contact with each other. In an inking device that removes excess ink and supplies the ink remaining on the peripheral surface toward the printing plate, the roller on the upstream side of the two rollers has a shorter distance from the shaft center than the peripheral surface of other parts. A roller having at least one relief portion formed of a surface, and the relief portion of the roller is 2
The gap between the peripheral surfaces of the two rollers is enlarged at the facing parts of the two rollers, and the ink that collects in the space where the proximity of the two rollers or the contact part is gradually narrowed by the rotation of the upstream roller causes the ink to collect in the rotation direction of the upstream roller. An inking device characterized in that it is provided so as to escape to the downstream side,

And

[0012] Two rollers, a downstream roller and an upstream roller rotating at a lower peripheral speed, are brought close to or in contact with each other, and excess ink is removed from the peripheral surface of the downstream roller to remain on the peripheral surface. In the inking device that supplies the ink to the printing plate, the roller on the upstream side of the two rollers is a roller having a polygonal cross section orthogonal to its axis, and each side of the polygon is a relief part. The relief portion expands the gap between the peripheral surfaces of the two rollers at the facing portion of the two rollers, and the ink accumulated in the vacant space where the proximity portion or the contact portion of the two rollers is gradually narrowed by the rotation of the upstream roller. Is provided so as to escape to the downstream side in the rotation direction of the upstream roller,

[0013]

[0014]

According to the structure of the present invention, the two that come close to or abut
By the rotation of the roller on the upstream side of the two rollers, it is brought to the proximity portion or the contact portion of these rollers, and gradually narrows toward the proximity portion or the contact portion on the upstream side in the rotation direction of the upstream roller having a slow peripheral speed. The ink accumulated in the vacant space is regularly transferred to the downstream side in the rotation direction of the upstream roller from the gap of the proximity portion or contact portion enlarged by the escape portion of the upstream roller passing through this proximity portion or contact portion. Let it escape.

Since the amount of ink to be released is regular, it does not increase, and no trouble occurs in removing excess ink on the peripheral surface of the downstream roller.

Further, due to the circumferential portion of the roller on the upstream side following the relief portion, ink is continuously brought to the proximity portion or the contact portion of the two rollers, and the ink to be supplied to the plate surface is not insufficient. .

[0017]

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

The inking unit has an upstream roller 1 and a downstream roller 2 which are adjacent to each other. Upstream roller 1
Has a relief portion 11 on its peripheral surface, and a part of the peripheral surface is dipped in the ink in the ink container 3 to rotate at a relatively low peripheral speed. The downstream side roller 2 is located at a position downstream of the upstream side roller 1 in the rotational direction from a position close to the upstream side roller 1, and an excess ink removing means 4 such as a doctor blade is in contact with the peripheral surface thereof. It rotates at a faster peripheral speed than the roller 1. Inking rollers 5 and 5 for supplying ink to a printing plate (not shown) mounted on the plate cylinder P are in contact with the downstream side of the roller 2 on the downstream side.

An ink tank 6 is provided below the ink container 3 and is connected to a supply port 7 for supplying ink to the ink container 3 by a pipe line 9 having a pump 8.

In the drawing, D is a dampening water device, B is a blanket cylinder, I is an impression cylinder, and W is a web material paper.

According to the configuration of the above embodiment, the ink container 3 is replenished with ink from the ink tank 6 through the replenishment port 7, and the ink overflowing from the ink container 3 is stored in the ink tank 6.

The ink in the ink container 3 adheres to the peripheral surface of the roller 1 on the upstream side and is brought to the vicinity of the roller 1 on the upstream side and the roller 2 on the downstream side by the rotation of the roller 1 on the upstream side. , Transferred to the peripheral surface of the roller 2 on the downstream side,
By the rotation of the roller 2 on the downstream side, it reaches the position of the excess ink removing means 4 and the excess is removed. The ink remaining on the peripheral surface of the roller 2 on the downstream side, which has passed the position where the excess ink removing means 4 comes into contact, is supplied to a printing plate (not shown) mounted on the plate cylinder P via the inking rollers 5 and 5. Then, the web material W is printed through the blanket surface (not shown) of the blanket cylinder B.

Further, the roller 1 on the upstream side brings the roller 1 on the upstream side to the proximity portion α between the roller 1 on the downstream side and the roller 2 on the downstream side, and the proximity portion α on the upstream side in the rotation direction of the roller 1 on the upstream side. The dampening water that gradually increases in the space A that gradually narrows toward the portion α and enters the ink supply path from the plate surface through the ink forming rollers 5 and 5 and that gradually increases with the ink that gradually increases in the space A is on the upstream side. The relief portion 11 provided on the roller 1 reaches a portion close to the downstream roller 2 and faces the peripheral surface of the downstream roller 2, and a gap between the upstream roller 1 and the downstream roller 2 is formed. Each time it expands, it is released to the downstream side in the rotational direction of the upstream roller 1 in a relatively small amount, and by the rotation of the upstream roller 1 or from the peripheral surface of the downstream roller 2 by the excess ink removing means 4. Removed, It is accommodated in Nki container 3 and / or ink tank 6.

Therefore, a large amount of ink does not accumulate in the vacant space A, the gap between the upstream roller 1 and the downstream roller 2 is pruned and they pass through the gap all at once, and the excess ink removing means 4 is adversely affected. In addition, the peripheral surface of the roller 1 on the upstream side is slid off all at once, and the ink transferred to the roller 2 on the downstream side is not deficient.

Also, dampening water that has entered the ink supply path
A large amount is not accumulated in the vacant space A, and the print density is not reduced and roller stripping does not occur.

The relief portion 11 of the roller 1 on the upstream side is shown in FIG.
Alternatively, it may be formed in a flat shape as shown in FIG. 3 or may be formed in a curved shape as shown in FIG. 2 or 4. In each of the illustrated examples, the escape amount a (see FIG. 1) of the escape portion 11 is defined by the radius R1 of the circumscribed circle and the radius R2 of the inscribed circle of the shape of the cross section orthogonal to the axis of the roller 1 on the upstream side. It is the difference.

Further, the escape portion 11 may be formed in parallel with the axis of the roller 1 on the upstream side, or may be formed in a spiral shape so as to rotate with respect to the axis.

The present invention is not limited to the above-described embodiments, but includes design modifications without departing from the scope of the claims.

[0029]

As a result of the practice of the present invention, the ink supply to the plate surface is stabilized, and it becomes possible to continuously and stably obtain a high-quality printed surface.

[Brief description of drawings]

FIG. 1 is a front view showing a schematic configuration of an embodiment of the present invention.

FIG. 2 is a diagram showing a cross-sectional outer shape of a roller on the upstream side of the inking device of the present invention, which is different from that shown in FIG.

FIG. 3 is a diagram showing a cross-sectional outer shape of the roller on the upstream side of the inking device of the present invention, which is different from that shown in FIG.

FIG. 4 is a diagram showing a cross-sectional outer shape of the roller on the upstream side of the inking device of the present invention, which is different from that shown in FIG.

FIG. 5 is a front view showing a schematic configuration of a conventional inking device.

[Explanation of symbols]

 1 upstream roller 2 downstream roller 3 ink container 4 excess ink removing means 5 inking roller 6 ink tank 7 replenishment port 8 pump 9 conduit 11 escape area D dampening device P plate cylinder B blanket cylinder I impression cylinder W Web paper A A Space that gradually narrows a Escape amount IF Ink fountain FR Ink fountain roller MR Ink metering roller DB Doctor blade α Proximity

Claims (2)

[Claims] 1. A downstream roller and an upstream roller that rotates at a peripheral speed lower than the downstream roller are in close proximity to or in contact with each other to remove excess ink from the downstream roller peripheral surface. In the inking device that supplies the remaining ink to the printing plate toward the printing plate, the roller on the upstream side of the two rollers has at least a clearance portion having a peripheral surface whose distance from the shaft center is shorter than the peripheral surface of the other portion. It is a roller that has two rollers, and the escape portion of the roller expands the gap between the peripheral surfaces of the two rollers at the facing portion of the two rollers, and the proximity portion or contact portion of the two rollers gradually narrows due to the rotation of the upstream roller. An inking device that is provided so as to allow the ink that accumulates in some places to escape to the downstream side in the rotational direction of the roller on the upstream side. 2. A downstream roller and an upstream roller rotating at a peripheral speed lower than the downstream roller are in close proximity to or in contact with each other, and excess ink is removed from the downstream roller peripheral surface. In the inking device that supplies the remaining ink to the printing plate toward the printing plate, the roller on the upstream side of the two rollers is a roller having a polygonal cross section orthogonal to its axis, and each side of the polygon is It forms a relief portion, and the relief portion expands the gap between the peripheral surfaces of both rollers at the facing portion of the two rollers, and becomes a space where the proximity portion or contact portion of the two rollers gradually narrows due to the rotation of the upstream roller. An inking device provided so as to allow the accumulated ink to escape to the downstream side in the rotation direction of the roller on the upstream side.