JPH028901B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a continuous water supply device for continuously supplying dampening water to plates on a plate cylinder in a printing press.

In the lithographic printing method, the basis of the image is created on the surface of a hydrophilic-treated planographic plate by transfer platemaking or photolithography, then chemically treated to create a plate, and this plate is mounted on a plate cylinder. Then, printing is performed while supplying ink and dampening water to this. By doing this, water is repelled in the image areas that have fatty properties, and water is absorbed in the non-image areas that have water absorbency, so if fatty ink is supplied to this plate, it will not stick to the image areas. An image is formed by being repelled by the non-image area, and this image is transferred to printing paper and printed.

As a water supply device for supplying water to the plate in this type of lithographic printing press, an intermittent water supply type is widely used, and this consists of a water source roller rotating in a water tank and a swinging roller downstream of it. In between, there is a transfer roller that is supported by a swing lever and moves back and forth between both rollers, and the water that has been carried around by the water base roller is intermittently transferred to the shaking roller and leveled.
It is designed to be supplied to the plate using a swimsuit roller.

However, in such a water supply device, water is supplied intermittently due to the reciprocating movement of the transfer roller, which causes uneven water supply, which causes differences in the amount of ink adhering, resulting in dark and light prints. As an alternative, a continuous water supply device has been developed that continuously supplies water without reciprocating the transfer roller. Various continuous water supply devices have been proposed.

However, in this type of continuous water supply device, the water supplied to the plate is returned to the water supply device and circulated, making it difficult to adjust the contact pressure between each roller, prolonging the adjustment time, and reducing waste paper. There was a problem that the number of occurrences increased. Therefore, the special public
-14341, a pair of opposing rollers in a group of water supply rollers are rotated in opposite directions at different speeds, and the water film on the rollers is stretched thinly by this speed difference, thereby forming the necessary water film. However, since the rollers with this speed difference move in the same direction at the point of contact, this prevents water returning from the plate from passing through this point of contact. This is difficult, and it is difficult to set the adjustment pressure in anticipation of this amount in advance, and it is difficult to expect a satisfactory effect. In addition, when a large amount of water is supplied due to a temporary interruption of printing, etc., the water returned from the plate enters the supply side again as described above, so a different amount of water than the set amount is supplied. There was a problem in that it took a long time to restore the system to its normal state.

The present invention has been made in view of the above points, and it is possible to easily achieve the present invention by rotating the swimsuit roller that contacts the plate cylinder and the transfer roller that contacts this in such a direction that their contact surfaces face in opposite directions. The present invention provides a water supply device for a printing press that stably supplies a preset minimum amount of water to the plate through proper adjustment to improve the quality of printed matter.

Hereinafter, its configuration and the like will be explained in detail with reference to embodiments shown in the drawings.

1 to 4 show a water supply device for a printing press according to the present invention, FIG. 1 is a schematic side view showing the water supply device and a part of the inking device, FIG. 2 is a side view of the water supply device, and FIG. 3 is a longitudinal sectional view, and FIG. 4 is an explanatory diagram of the water supply operation. In these figures, a printing cylinder 2 that rotates in the direction shown by the arrow A in the figures is pivotally supported on a frame 1 of a printing unit installed in a printing press, and above the plate cylinder 2 a pair of swinging rollers 3 are mounted. It is pivotally supported by the frame 1. A pair of ink forming rollers 4 are provided between each of the swinging rollers 3 and the plate cylinder 2, and are supported by roller arms that are formed to be able to freely swing around the swinging rollers 3. The ink forming roller 4 is configured so that it can be attached to and detached from the plate cylinder 2 while facing the swinging roller 3 using an attachment/detachment mechanism. The ink transferred from an ink fountain (not shown) to the swinging roller 3 via a large number of roller groups is transferred to the ink forming roller 3.
is supplied to the plate on the plate cylinder 2.

On the side of the plate cylinder 2 to which ink is supplied in this way, a transfer roller 5 having a hydrophilic surface is pivotally supported by the frame 1 via a bearing 6. A sprocket 8, which is integral with the attached gear 7, is drivingly connected to a sprocket 10 of a variable speed motor 9 by a chain 11, and is configured to rotate in the opposite direction to the plate cylinder 2, as shown by arrow B in the figure. has been done. A lever 12 and a water roller lever 13 are rotatably fitted into a bearing 6 that pivotally supports the transfer roller 5, with their movement in the axial direction being restricted by a collar 14. The swinging range of the lever 12 is adjustable by a stopper 15 implanted in the frame 1 and an adjustable adjustment screw 16 attached to the frame 1. And this lever 12
A roller lever 17 formed in an inverted T shape is pivotally attached to the free end of the lever, and one horizontal end of the roller lever 17 is pivoted to the free end of the lever.
A swimsuit roller 18 having an elastic surface and rotating in the same direction as the transfer roller 5 as shown by arrow C in the figure, that is, in a direction in which the opposing circumferential surface faces in the opposite direction, is pivotally supported. Furthermore, roller lever 1
A rod holder 19 is pivotally supported at the other horizontal end of the rod 7, and an insertion hole 20 bored in the protrusion of the rod holder 19 includes a rod holder 19.
One end of the adjustment rod 22 is pivotally connected to the jaw of the lever 12 by a pin 21, and the other end of the adjustment rod 22 is pivotally supported. The head of the adjustment rod 22 is threaded, and an adjustment nut 23 is screwed into the threaded portion. In addition, the rod receiver 19 and the adjustment rod 22
A roller lever 17 is installed between the lower end step part of the second
A compression coil spring 24 is interposed to move the swimsuit roller 18 into pressure contact with the roller 5 by rotating clockwise in the figure, and by rotating an adjustment nut 23, the contact pressure between both rollers 5 and 18 can be adjusted. is configured to be Furthermore, the roller lever 17
The rod end of an air cylinder 25 is pivotally attached to the vertical end of the roller lever 1 by a pin 26.
7 and the lever 12 swing together, and the swimsuit roller 18 is configured to be attached to and detached from the plate cylinder 2 while the rollers 5 and 18 remain in contact with each other.

On the other hand, at the free end of the water base roller lever 13, there is a roller support shaft 27 consisting of an eccentric shaft support 27a and a bearing 27b, as shown by the symbol t in FIG.
However, movement in the axial direction is restricted by the stepped portion and the collar 28, and it is rotatably supported. Further, a rod receiver 29 is provided on the side of the lower end of the water base roller lever 13 and is fixed to the frame 1.
The other end of an adjustment rod 31, one end of which is pivotally connected to the jaw portion of the water base roller lever 13 by a pin 30, is pivotally supported in the insertion hole. The head of the adjustment rod 31 is threaded, and an adjustment nut 32 is screwed into this threaded portion. Further, a compression coil spring 33 is interposed between the rod receiver 29 and the stepped portion of the adjustment rod 31 to apply a rotational force to the water base roller lever 13 in the counterclockwise direction in FIG. The bearing part 27b of the roller support shaft 27 has an elastic surface, and is connected to the transfer roller 5 by gears 7 and 34, and rotates in the opposite direction to the transfer roller as shown by arrow D in the figure. 35
is immersed in water 37 in a water boat 36 and supported pivotably. Note that a rotating lever (not shown) is attached to the bearing portion 27b of the roller support shaft 27, and by operating this lever to rotate the bearing portion 27b, the contact pressure of the water base roller 35 against the transfer roller 5 is reduced. It is configured to be adjustable.

The operation of the water supply device configured as above will be explained. First, before printing, the adjustment nut 23 is rotated to adjust the contact pressure between the swimsuit roller 18 and the transfer roller 5, and the roller support shaft 27 is rotated to adjust the contact pressure between the water base roller 35 and the transfer roller 5. Adjust contact pressure. Furthermore, by rotating the left and right adjustment nuts 32, the left and right water head roller levers 13 are rotated separately, so the axis of the water head roller 35 can be twisted relative to the axis of the transfer roller 5. The contact pressure between both rollers 35 and 5 can be changed in the axial direction.

In the non-printing state after preparation in this way, the air cylinder 25 is contracted and the lever 12
is in contact with the stopper 15, and the roller lever 1
Only spring 7 rotates counterclockwise and compressed coil spring 2
4 is compressed. Therefore, the swimsuit roller 18
is remote from both the plate cylinder 2 and the transfer roller 5. When starting printing, when the air cylinder 25 is extended, the swimsuit roller 18 is first moved by the transfer roller 5 due to the elasticity of the compression coil spring 22.
, and then roller lever 17 and lever 12
The swimsuit roller 18 rotates together, and the swimsuit roller 18 comes into contact with the plate on the plate cylinder 2. In this case, the contact pressure of the swimwear roller 18 against the printing plate is regulated by the position of the adjustment screw 16 that has been adjusted in advance. In this way, all the water supply rollers are in contact with each other.

Therefore, the water supply operation after the start of printing will be explained with reference to FIG. A part of the water 37 stored in the water boat 36 is pulled up as a water film 41 by the water base roller 35 rotating in the direction of arrow D, and is pulled up by the water roller 35 rotating in the direction of arrow D.
It is drawn into the contact area with. Since the pressure at this contact portion is adjusted by the roller support shaft 27 and the adjustment nut 32 as described above, the water film 4
Only a part of the water bottle 1 passes between the rollers 35 and 5 and is pushed out, and the rest falls and is returned to the water boat 36.
The water film 41 that has passed through the contact portion is divided into two parts, one half of which is transferred to the transfer roller 5 rotating in the direction of arrow B, and the other half of the water film 4 is transferred to the transfer roller 5 that rotates in the direction of arrow B.
2b is returned to the water boat 36 by the water source roller 35. Water film 42a carried by transfer roller 5
When the contact point with the swimsuit roller 18 is reached, most of the water film 43 is removed because both rollers 5 and 18 are rotating in a direction in which the contacting peripheral surfaces face in opposite directions.
Then, it is transferred to the swimsuit roller 18 and carried in the direction of arrow C. In this case, the circumferential speed of the swimwear roller 18 is generally higher than the circumferential speed of the transfer roller 5, and the thickness of the water film 43 is determined by the difference in the circumferential speed of both rollers 5 and 18 and the water carried to the contact area. It is determined by the thickness of the water film 42a. The water film 43 then reaches a point of contact with the plate surface on the plate cylinder 2, merges with the water film 44 remaining on the plate, passes through the contact point, and is divided into two. Half of the water film 45a corresponds to the thickness of the water supply to the plate and moves toward the contact point between the inking roller 14 and the plate. The other water film 45b is formed by the swimsuit roller 18.
Most of it is transferred to the transfer roller 5, forms a water film 46, merges with the water film 41, and the above transfer is repeated, or is returned to the water boat 36. .

In the water supply operation performed in this manner, the swimsuit roller 18 and the transfer roller 5 rotate so that their contact peripheral surfaces face in opposite directions at the contact point, so that water entering the contact point, That is, the water film whose thickness is adjusted by the gap or contact pressure between the water base roller 35 and the transfer roller 5 is further adjusted by the speed of the transfer roller 5 and transferred to the plate surface via the swim roller 18. do. On the other hand, the water returned from the printing plate to the swimsuit roller 18 is not transferred to the printing cylinder 2 again, but is passed through the transfer roller 5 to the swimsuit roller 3
Returned to 6. Only the water adjusted in this way becomes the amount supplied to the plate cylinder 2, so it is possible to reliably adjust the amount of water supplied, and the excess water is quickly disposed of through a different route from the supply side. As you will be returned to boat 36,
Adjustment response speed is fast and adjustment is easy. In addition, by quickly recovering excess water in this manner, an imbalance with ink can be balanced in a short time, for example, when printing is interrupted and then restarted.

FIG. 5 is a schematic side view showing another embodiment of the present invention corresponding to FIG. It is provided. The rider roller 51 is capable of reciprocating in the axial direction. By doing this, the ink transferred from the plate on the plate cylinder 2 to the swimsuit roller 18 can be leveled in the axial direction, so that the distribution of water to the swimsuit roller 18 can be made even more uniform. Note that the rider roller 51 is desirably driven to rotate at the same circumferential speed as the plate cylinder 2.

Furthermore, FIG. 6 is a schematic side view showing another embodiment of the present invention corresponding to FIG. 1, and in this embodiment, the water head roller 35 in the embodiment shown in FIG. 36 and placed above and in contact with the transfer roller 5, and instead the transfer roller 5 is immersed in the water of the water boat 36. Also in this embodiment, the swimsuit roller 18 and the transfer roller 5
and are rotated in a direction in which the contacting peripheral surfaces are directed in opposite directions, so that substantially the same effect as shown in FIG. 1 can be achieved. However, in this case, since the rotation direction of the water supply roller group is opposite to that shown in FIG. However, such an arrangement can be used when space is limited due to the configuration of the printing press or for operational reasons.

Furthermore, FIG. 6 is a schematic side view showing another embodiment of the present invention corresponding to FIG. 1, and in this embodiment, the swimsuit roller 18 in the roller arrangement shown in FIG. One swimsuit roller 18A serves as the closest ink deposition roller 4. By doing so, the necessary water can be supplied to the ink roller group before printing starts, that is, before water and ink are supplied to the plate cylinder 2.

As is clear from the above description, according to the present invention, in the water supply device of a printing press, the swimsuit roller that is in contact with the plate cylinder and the transfer roller that is in contact with this are rotated in a direction so that their contact surfaces face in opposite directions. By doing so, only the amount of water supplied to the plate is controlled by the gap or contact pressure between the water base roller and the transfer roller and the rotation speed of the transfer roller, so the minimum amount of water is always required. Water can be supplied to the plate in a stable state, and the amount of water supplied can be reliably and easily adjusted, the adjustment time can be shortened, and the amount of paper waste generated can be significantly reduced.

[Brief explanation of drawings]

1 to 6 show a water supply device for a printing press according to the present invention, FIG. 1 is a schematic side view showing the water supply device and a part of the inking device, FIG. 2 is a side view of the water supply device, and FIG. 3 is a longitudinal sectional view, FIG. 4 is an explanatory view of the water supply operation, and FIGS. 5 and 6 are schematic side views showing other embodiments of the present invention corresponding to FIG. 1. 2... Plate cylinder, 5... Transfer roller, 18... Swimsuit roller, 35... Mizumoto roller, 36... Mizifune, 3
7...Water.

Claims (1)

[Claims] 1. A swimsuit roller 18 having an elastic surface that rotates in contact with the plate on the plate cylinder 2, and a speed adjustable in the same direction as the swimsuit roller 18 so that the facing surfaces facing the swimsuit roller 18 face in opposite directions. A transfer roller 5 having a hydrophilic surface that is rotationally driven, and a water base roller 35 having an elastic surface that is immersed in water and is supported in opposition to the transfer roller 5 so that the contact pressure therewith can be adjusted. A water supply device for a printing press characterized by: