JPH0567422B2 - - Google Patents

Description

Detailed Description of the Invention [Technical Field of Industrial Application] The present invention relates to a rotary printing press for offset printing, for example, in which a constant amount of moisture is always applied to the plate wound around the plate cylinder in order to achieve good printing. This invention relates to a dampening water device that can stably supply dampening water.

[Prior art]

In the field of printing technology, the development of offset printing machines has made it possible to achieve extremely good printing. This offset printing machine is generally a rotary printing machine in which a printing plate is wound around a substantially cylindrical plate cylinder, and ink and dampening water are supplied to the plate by a plurality of ink rollers. It will be done.

This plate is designed to have a lipophilic surface-treated portion corresponding to the text and pattern portions, and a hydrophilic surface-treated portion corresponding to the other portions. The ink and water that are supplied to the entire area of the plate by a predetermined ink roller are designed so that the ink adheres to the lipophilic areas and the water adheres to the hydrophilic areas, resulting in the repulsion between oil and water. This allows the letters to clearly outline the outline of the picture. Further, the ink adhering to the plate is transferred via the plate to a rubber blanket cylinder that is in rolling contact with the plate cylinder, and then transferred to the paper.

By the way, in such a rotary printing press, the part that supplies dampening water to the plate is called a dampening water device.
For example, as shown in FIG. 1, dampening water contained in a water bucket 11 is immersed in the dampening water and lifted up by a rotating dampening roller 12, and the dampening water is lifted by a contact pressure (hereinafter referred to as nip pressure). ) or a gap, the water is supplied to the plate 17 wound around the plate cylinder 16 by a water transfer roller 13, a water leveling roller 14, and a swim roller 15, which rotate as shown by the arrows in the figure.

Further, as described above, the ink supplied to the printing plate 17 via the ink roller group of the inking device (not shown) is transferred to the printing paper 19 which is sent in the direction of the arrow A in the drawing.
It will be transferred to the rubber cylinder 18.

In the dampening water device shown in FIG. 1, a dampening roller 12 that supplies dampening water from a water cannon 11 to a water transfer roller 13 is rotationally driven by a drive device 20. This drive device 20 is designed to allow the operator to arbitrarily set the rotational drive speed of the dampening roller 12, so that the amount of dampening water finally supplied to the plate 17 can be set to an optimal value. It's becoming like that.

Further, the water leveling roller 14 rotates while reciprocating in the direction of the rotation axis, and the water leveling roller 13
The dampening water supplied to the printing paper 19 is evenly distributed in the width direction of the printing paper 19 and then supplied to the printing plate 17 via the dampening roller 15. An example of a drive mechanism is 16
and 15 is caused by a gear, and 15→14→13 is caused by friction between rollers, but the present invention is not limited to this example.

In such a dampening water device, the amount of dampening water is controlled by not only changing the rotation speed of the dampening roller 12, but also by changing the rotation speed of the dampening roller 12, the water transfer roller 13,
This can also be achieved by appropriately changing the nip pressure or gap distance between the water leveling roller 14 and the swimwear roller 15.

On the other hand, the dampening water device shown in FIG. On the other hand, by making appropriate sliding contact, an optimum amount of dampening water can be supplied to the plate 17 on the plate cylinder 16. However, in Figure 2, the first
Components that are the same as those in the drawings are given the same reference numerals and their explanations will be omitted.

In this dampening water device, draining plates 230 to 23
By slidingly contacting the water draining roller 12 with the water draining roller 12, the sliding contact portion is drained, and by separating the draining plates 230 to 239 from the water draining roller 12, the draining plate 2 is removed.
Since water can be supplied to the portion of the plate 17 corresponding to sections 30 to 239, this type of dampening water device can only choose between draining water to the plate 17 or sending water to the plate 17.

In a rotary printing press using the dampening water device described above, the amount of dampening water to be supplied is adjusted by a skilled printing operator while observing the actual printing conditions and checking the average water amount over the entire plate area and the width direction of the printing paper during the printing operation. The actual printing work was carried out by adjusting the water volume distribution.

In such a dampening device, the average water amount over the entire plate area and the water amount distribution in the width direction of the printing paper can be adjusted by, for example, changing the rotation speed of the dampening roller, adjusting the gap or nip between the water rollers, This is done by sliding a drain plate on the roller as appropriate.
In these adjustment operations, the image area of the printing paper that requires a large amount of ink requires a large amount of dampening water compared to the ink, and the area that does not require a large amount of ink requires a large amount of dampening water. don't need much. That is, it was not possible to control the amount of dampening water in proportion to the amount of ink in the image area. Therefore, it has been impossible to appropriately adjust the distribution of the amount of dampening water in the width direction of the wetting roller in accordance with the image area.

[Purpose of the invention]

The present invention provides a dampening water device that can appropriately adjust the distribution of the amount of dampening water in the width direction of a dampening roller in accordance with the image area.

[Embodiments of the invention]

Next, embodiments of the dampening water device according to the present invention will be described in detail below with reference to the accompanying drawings. Third
The figure is a schematic diagram of a dampening water device showing an embodiment of the present invention, and in the figure, parts having the same functions as those in FIGS. 1 and 2 are designated by the same reference numerals, and the explanation thereof will be omitted. 30 ₁ ...30 _N
is a cartridge attached to a water boat 11 provided corresponding to each of the water draining plates 23 ₁ to 23 _N.

Figure 4 shows part 1 of the drain plates 23 ₁ to 23 _N.
For example, this is a cross-sectional view of the main parts showing the relationship between the drain plate 23 ₁ and the cartridge 30 ₁ .
0 ₁ is a pulse motor 32 with a reducer attached to a case 31, and a shaft 3 rotatably attached to the case 31.
3, a spherical cam follower 35 fixed to the lever 34, and a shaft 37 connected to the shaft of the pulse motor 32 with a reducer via a joint 36 and rotatably supported by the case 31. The main component is a plate cam 38 that is in contact with a spherical cam follower 35. A compression coil spring 39 pushes the lever 34 through a cover 40 covering the upper surface of the case 31 to prevent the spherical cam follower 35 from separating from the plate cam 38. The draining plates 23 ₁ to 23 _N are made of an elastic material and are attached to the lever 34 so as to be able to absorb inevitable errors in pressing the draining roller 12 against the draining roller 12 .

In such a configuration, the pulse motor 32 with a speed reducer
When driven, the plate cam 38 rotates via the joint 36 and shaft 37, and the rotation of the plate cam 38 causes the spherical cam follower 35 to follow the movement of the plate cam 38 and move up and down in the figure. The movement of the spherical cam follower 35 causes the lever 34 to move up and down in the figure around the shaft 33, so that the draining plate ₂₃₁ also cooperates.

Next, the operation of the present invention will be explained. In FIG. 3, first, the rotational speed of the dampening roller 12 is adjusted by the drive device 20 (see FIG. 1) so that the dampening water spreads evenly over the entire area of the plate 17.

Next, in order to adjust the moisture content of the dampening solution depending on the condition of the printed material, among the drain plate groups 23 ₁ ... 23 _N , there are sections where the moisture content of the dampening solution needs to be adjusted, such as the drain plate 23 ₁ . When adjusting the dampening water in the cartridge 30 1 , the rotational speed of the pulse motor 32 with a speed reducer in the cartridge 30 ₁ is controlled by a known control device (not shown).
3. The amount of dampening water applied to the dampening roller 12 is adjusted by controlling the number of times per unit time of "putting on" and "taking off" that change continuously in step ₁ . At this time, this drain plate 23
₁ moves along the curve of the plate cam when moving from "on" to "off" and from "off" to "on". It becomes movement. Therefore, the thickness of the water film supplied to the water dispenser roller 12 changes smoothly, and water can be supplied without streaks.

In addition, the amount of water can be adjusted by using the water draining roller 12 of the draining plate ₂₃₁ .
Since the feed is adjusted by "putting on" and "taking off" on the printed material, there will naturally be troughs or stripes in the paper feed direction that can be distinguished by the quality of printing, but it is important to set the interval appropriately. If the water is set to a certain value, it will be leveled and made uniform by another water roller interposed between the water dispenser roller 12 and the plate 17. In addition, the unevenness in the width direction is caused by the leveling roller 1 that swings in the axial direction.
4 results in a smooth water volume distribution.

Therefore, if the time for ``putting on'' is longer than the time for ``taking off'', there will be fewer trips up the water, and if the opposite is true, there will be more trips up the water.

In this embodiment, a pulse motor 32 with a speed reducer is used.
Drain plate 23 ₁ ~ with rotary solenoid instead of
It is also possible to control 23 _N individually.

In this embodiment, the case where the draining plate comes into contact with and separates from the draining roller has been described, but the draining plate may be provided in the draining roller group.

〔Effect of the invention〕

Maintenance is easy because a cartridge is provided for each drain plate and a reducer pulse motor is attached to each cartridge to form a cassette type. Further, the present invention is effective in controlling the dampening water by the nip pressure between the dripping roller and the water transfer roller.

[Brief explanation of the drawing]

Figures 1 and 2 are schematic diagrams of conventional dampening water devices;
FIG. 3 is a schematic diagram of a dampening device according to an embodiment of the present invention;
FIG. 4 is an enlarged view of the main parts of the cartridge shown in FIG. 3. FIG. 5 is an explanatory diagram of the water film thickness of the wetting roller in the present invention. 11... Mizifune, 12... Laura Mizude, 13...
Water transfer roller, 14... Water leveling roller, 15... Swimsuit roller, 16... Plate cylinder, 17... Plate, 18...
Rubber cylinder, 23 ₁ ... 23 _N ... Draining plate, 30 ₁ ... 30 _N
……Cartridge, 31……Case, 32……
Pulse motor with reducer, 33... shaft, 34... lever, 35... spherical cam follower, 36... joint, 37... shaft, 38... plate cam, 39... compression coil spring, 40... cover.

Claims (1)

[Claims] 1 In a dampening water device of a rotary press that supplies dampening water via multiple rollers to a printing cylinder that is wound around the printing cylinder and is supplied with ink by a predetermined means, A divided draining plate arranged and in contact with the circumferential surface of the pouring roller, a lever attached to a shaft rotatably supported by the case to which the draining plate is attached, and a lever corresponding to each of the levers. a pulse motor with a speed reducer mounted on the case, a plate cam with a smooth continuous large diameter part and a small diameter part mounted on the shaft of the pulse motor, and a plate cam mounted on the lever. The cam follower rotates in contact with the plate cam, and the cam rotates due to the rotation of the pulse motor with a reduction gear, and the cam follower continuously moves up and down due to the rotation of the plate cam. A dampening water device characterized by continuously adjusting the contact time period to a delivery roller in a stepless and analog manner.