JP2001001490A - Damping water supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the amt. of damping water variable during printing work and to supply a large amt. of damping water especially at an initial stage of printing. SOLUTION: A damping water supply means 14 is equipped with a water fountain roller 31 arranged so as to be partially immersed in a water shoe 30, the form-damping roller 32 arranged so as to be able to come into contact with the printing plate on a plate cylinder 10, the intermediate roller 33 arranged between the water fountain troller 31 and the form-damping roller 32 and a nip pressure adjusting means 34 for adjusting the nip pressure between the water fountain roller 31 and the intermediate roller 33. The rotary shafts provided to both ends of the water fountain roller 31 are eccentrically supported by bearings 35, 36 and gear parts are formed to the outer peripheries of the bearings 35, 36. The nip pressure adjusting means 34 has a rotary shaft 47 to which the gears 45, 46 meshed with the gear parts of the bearings 35, 36 are fixed and the motor 48 for driving the rotary shaft 47.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fountain solution supply apparatus for applying a fountain solution to a printing plate in a printing apparatus, and more particularly, to a fountain solution optimal for a printing apparatus having a plate making mechanism for making a plate on a plate cylinder. It relates to a supply device.

[0002]

2. Description of the Related Art In a conventional general printing apparatus, printing is performed by mounting a printing plate on a plate cylinder, but in recent years, there is provided a plate making mechanism for making a printing plate directly on the plate cylinder. Printing device is provided. As such a printing apparatus, for example, there is a printing apparatus disclosed in Japanese Patent Laid-Open Publication No. Hei 10-272756 by the present applicant, and is generally called a digital printing machine.

[0003] The printing apparatus disclosed in the above publication has two sets of plate cylinders, and each plate cylinder is configured to be movable to a unique printing position and a common plate making position. The plate making position is provided with a plate making mechanism used for both plate cylinders, for example, a supply means of unexposed printing plate, a laser exposure means, etc., and a printing mechanism used for each plate cylinder at each printing position. For example, fountain solution supply means and ink supply means are provided.

On the other hand, in a dampening water supply device in a general printing apparatus, a damper roller immersed in a watercraft storing dampening water is rotated to pump up dampening water, and an intermediate roller and a dampening roller are driven. There is a fountain solution supply device of a continuous water supply type which is applied to a printing plate surface through the fountain solution. In this conventional dampening water supply device, the number of revolutions of the water supply roller is varied to adjust the supply amount of dampening water.

[0005]

However, depending on the type of printing plate, it was necessary to change the supply amount of the dampening solution during the printing operation. For example, in the digital printing machine, when a predetermined printing plate for laser exposure is used, a large amount of dampening solution may be used in the initial stage of printing to stabilize print quality. However, merely increasing the number of rotations of the fountain roller has a limit in increasing the amount of dampening solution supplied, and is insufficient when supplying a large amount of dampening solution in a short time.

An object of the present invention is to provide a dampening solution supply device capable of supplying a large amount of dampening solution in a short period of time at the beginning of printing.

[0007]

According to the first aspect of the present invention, there is provided a water roller partially immersed in a watercraft for storing dampening water, an intermediate roller contacting the water roller, and an intermediate roller. A dampening water supply device having a dampening roller that receives dampening water from a roller and supplies dampening water to the printing plate on the plate cylinder, wherein a nip pressure between the water source roller and the intermediate roller can be changed. Nip pressure adjusting means, and control means for controlling the nip pressure adjusting means so as to change the nip pressure during a printing operation.

In the invention according to claim 2, the control means adjusts the nip pressure to the first nip pressure before the start of work, and adjusts any one of the number of prints, the number of rotations of the printing apparatus, or the operating time. After a predetermined value has elapsed, the nip pressure adjusting means is controlled so as to adjust to a second nip pressure stronger than the first nip pressure.

According to a third aspect of the present invention, the nip pressure adjusting means includes an eccentric bearing means for eccentrically supporting at least one of the water roller and the intermediate roller, and a rotating means for rotating the eccentric bearing means. Means.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a view showing an example of a printing apparatus employing a dampening solution supply device according to the present invention, and FIG. 2 is a block diagram of the printing apparatus.

Referring to FIG. 1, a printing apparatus according to the present embodiment includes a first printing unit 1 and a second printing unit 2 capable of performing multi-color printing of two colors each, and printing paper on the first printing unit. A paper feed unit 3 for feeding, an intermediate transport unit 4 for transporting print paper from the first print unit 1 to the second print unit 2, a paper discharge unit 5 for discharging print paper from the second print unit 2, Drive unit 6 which drives the printer synchronously
And

As shown in FIG. 2, each section of the printing apparatus is electrically connected to the control means 7. The control means 7 is composed of a microcomputer having input / output means and storage means (not shown), and controls each section of the printing apparatus in accordance with a predetermined procedure in accordance with an operator's instruction.

On the other hand, the control means 7 is also connected to an external image data generating device 8 such as a DTP (Desk-Top-Publishing) device via a LAN or the like, and receives image data used for printing and RIP ( Raster-Im
Data processing such as age-Processing is performed, and image data is supplied to an image recording unit 12 described later.

The first printing unit 1 has a plate cylinder 10 capable of holding printing plates corresponding to two printing areas on a peripheral surface thereof, and plate supply / discharge means 11 for supplying and discharging the printing plate to and from the plate cylinder.
An image recording unit 12 for forming an image on the printing plate on the plate cylinder 10, a developing unit 13 for developing the printing plate on which the image has been formed, and two dampening solutions for supplying dampening solution to the printing plate. A supply unit 14, two ink supply units 15 for supplying ink to the printing plate, a blanket cylinder 16 having the same diameter as the plate cylinder 10 and abutting on the plate cylinder 10, and a half of the plate cylinder. An impression cylinder 17 having a diameter of 3 mm and contacting the blanket cylinder 16, and a feed cylinder 18 and a discharge cylinder 19 for supplying and discharging printing paper to and from the impression cylinder 17.

The plate cylinder 10 has two sets of gripping means (not shown) on its peripheral surface, and print plates corresponding to different colors.
It is configured to be able to hold one sheet. By holding one printing plate having two printing regions instead of two printing plates, two printing plates may be provided substantially on one plate cylinder.

The plate supply / discharge means 11 supplies an unexposed printing plate to the plate cylinder 10 and collects a used printing plate from the plate cylinder 10. The supply / discharge cassette (not shown) includes It comprises transport means (not shown) for transporting the printing plate between the cassette and the plate cylinder 10.

The image recording means 12 records an image by irradiating the printing plate on the plate cylinder 10 with a light beam. In the present embodiment, the image recording unit 12 performs sub-scan feed of a beam irradiation unit that irradiates the printing plate by turning on / off a light beam in accordance with an image signal in the axial direction of the plate cylinder 10. To form an image.

The developing means 13 is composed of a processing liquid tank storing a processing liquid and an application roller arranged so as to be partially immersed in the processing liquid. The processing solution is pumped up and supplied to the printing plate surface. In this embodiment, each processing liquid tank and coating roller have two sets for developing processing and fixing processing, respectively, and an elevating mechanism is provided so that each of them independently comes into contact with and separates from the plate cylinder 10. ing. Depending on the type of printing plate, the case where the developing means 13 itself is unnecessary may be considered.

The dampening solution supply means 14 is a dampening solution supply device according to the present invention, and two sets of dampening solution supply means 14 are provided for one plate cylinder 10. Each dampening solution supply means 14 is connected to the plate cylinder 10 by a cam mechanism (not shown).
It is configured to selectively supply a dampening solution to each of the different printing areas above. This dampening water supply means 14
Will be described later in detail.

The ink supply means 15 is a means for selectively supplying different colors of ink to different printing areas on the plate cylinder 10 to which the dampening solution has been supplied by the dampening solution supply means 14. There is an ink fountain storing ink and a plurality of ink rollers for taking out ink from the ink fountain and supplying the ink onto the printing plate surface. At least a roller of the ink roller that comes into contact with the printing plate is configured to come into contact with or separate from the plate cylinder 10 by a cam mechanism or the like, and is selected with respect to a corresponding printing area on the plate cylinder 10. The ink can be supplied in an appropriate manner.

The blanket cylinder 16 has the same diameter as the plate cylinder 10 and has a blanket surface on its peripheral surface for transferring an ink image. Two ink images are transferred from the printing plate on the plate cylinder 10 to this blanket surface. A blanket cleaning means 20 for cleaning the blanket surface is provided around the blanket cylinder 16.

The impression cylinder 17 has a half diameter of the plate cylinder 10, and a set of gripping means (not shown) is provided on a peripheral surface thereof. Therefore, on the peripheral surface of the impression cylinder 17, one printing sheet of a size corresponding to one printing area of the plate cylinder 10 can be held. The gripping means of the impression cylinder 17 opens and closes so as to receive the printing paper from the paper feeding cylinder 18 described later every other rotation and to deliver the printing paper to the paper ejection cylinder 19 described later every other rotation. .

The feed cylinder 18 and the discharge cylinder 19 are
And a pair of gripping means (not shown) for holding printing paper on the peripheral surface thereof. Both the paper feed cylinder 18 and the paper discharge cylinder 19 are rotated in synchronization with the impression cylinder 17, and the phase is set so that the gripping means of each cylinder and the gripping means of the impression cylinder 17 face each other. . The gripping means of the paper supply cylinder 18 and the paper discharge cylinder 19 also open and close so that the printing paper can be supplied and discharged every time the impression cylinder 17 rotates twice.

In the first printing unit 1, the plate cylinder 1
Based on the difference between 0 and the diameter of the blanket cylinder 16 and the diameter of the impression cylinder 17, when the plate cylinder 10 and the blanket cylinder 16 make one rotation, the impression cylinder 17 makes two rotations. Therefore, the impression cylinder 17
Is rotated twice while holding the printing paper, the ink images are transferred from the two printing areas on the plate cylinder 10 onto the printing paper, and two-color printing can be performed.

The configuration of the second printing unit 2 is basically the same as that of the first printing unit 1, so the same reference numerals are given in FIG. 1 and the description is omitted. In the present embodiment, the colors of the ink supplied by the ink supply means 15 of the first printing unit 1 are K (black) and C (cyan), and the color of the ink of the second printing unit 2 is M (magenta). ) And Y (yellow).

The paper feed unit 3 includes a paper feed tray on which print papers are loaded, and separates and takes out only one uppermost print paper from among the print papers loaded on the paper feed tray. To be supplied to The operation of separating and supplying the printing paper by the paper supply unit 3 is performed every time the paper supply cylinder 18 rotates every other rotation.

The intermediate transport section 4 transfers printing paper between the discharge cylinder 19 of the first printing unit 1 and the paper feeding cylinder 18 of the second printing unit 2. It is configured. Each transfer cylinder 21 has a diameter twice as large as that of the impression cylinder 17, and two sets of gripping means (not shown) are provided on the peripheral surface thereof. The gripping means of each transfer cylinder 21 and the gripping means of the paper discharge cylinder 19 and the paper feed cylinder 18 are configured so as to be synchronously opened and closed in phases opposite to each other so as to transfer the printing paper. ing.

As described above, since the impression cylinder 17 performs two-color printing every two rotations, when a transfer cylinder 21 having a diameter twice as large as that of the impression cylinder 17 is used, one set of You may make it provide only a jaw means. That is, in this case, only half of the peripheral surface of each transfer cylinder 21 is used for conveying the printing paper. However, in the printing apparatus of the present embodiment, each transfer cylinder 21 is provided with two sets of gripping means in order to provide a single-sided two-color printing function in which each impression cylinder 17 rotates only once.

The paper discharge section 5 is composed of an endless chain provided with a gripper for receiving and transporting the print paper from the paper discharge cylinder 19 of the second printing unit 2 and a discharge stand for loading the print paper. Become.

The printing drive unit 6 is composed of a motor for rotating each of the cylinders of the printing apparatus. Each of the cylinders drives a gear (not shown) provided so as to mesh between adjacent cylinders. The torso is driven to rotate synchronously. The sheet feeding operation of the sheet feeding unit 3 is also synchronized with the print driving unit 6 by a synchronization unit (not shown).

Next, the dampening solution supply means 14 will be described with reference to FIGS. Here, FIG. 3 is a side view showing a main part of one dampening water supply means 14, and FIG. 4 is a top view of the dampening water supply means 14. Although the printing apparatus according to the present embodiment includes a total of four dampening water supply units 14, it has basically the same configuration, and therefore only one dampening water supply unit 14 will be described.

In the figure, a dampening water supply means 14 comprises a watercraft 30 for storing dampening water, a water source roller 31 arranged so as to be partially immersed in the watercraft, A watering roller 32 disposed so as to be able to contact the printing plate, an intermediate roller 33 disposed between the water supply roller and the watering roller and in contact with both rollers to transfer dampening water; A nip pressure adjusting means 34 for adjusting the nip pressure between the water roller 31 and the intermediate roller 33 is provided.

The watercraft 30 is a tray-shaped container having an open upper surface, in which a fixed amount of dampening water is stored. The dampening solution is circulated in a state where the temperature of the dampening solution is controlled by a circulating means and a cooling means (not shown).

The water source roller 31 is a rubber roller having a length substantially equal to the length of the plate cylinder 10 in the axial direction and having a smooth surface, and is rotatably supported by bearings 35 and 36. The bearings 35 and 36 eccentrically support the rotating shafts at both ends of the water source roller 31, respectively, and have a gear portion formed on the outer periphery thereof so as to mesh with gears 45 and 46 described later. The bearing 35 is rotatably supported by a gear 43 (described later) that is supported by a left plate (not shown), and the bearing 36 is supported by a right plate 37.

The water-applying roller 32 is a rubber roller whose surface is substantially the same as the length of the plate cylinder 10 in the axial direction, and is made of rubber. A gear 38 is fixed to one end of the rotating shaft. When the gear 38 meshes with a gear (not shown) provided on the plate cylinder 10, the wetting roller 32 is brought into contact with the plate cylinder 1.
It is driven to rotate in synchronization with 0. The watering roller 32
Are configured to come into contact with or separate from the plate cylinder 10 by a cam mechanism (not shown). Watering roller 3
2 has a rider roller 39 for smoothing out the ink particles transferred on the dipping roller.

The intermediate roller 33 is a metal roller having a length substantially equal to the length of the plate cylinder 10 in the axial direction and having a smooth surface. A driving gear 40 is fixed to one end of the rotating shaft, and the other end is Is provided with a swing cam 41. Here gear 4
0 meshes with a gear 43 that is rotationally driven via a pulley or the like by an intermediate roller driving motor 42. on the other hand,
The oscillating cam 41 has a sloping groove formed on the peripheral surface thereof, and a cam follower 44 having a sliding portion slidable in the groove.
Are fixed to a second side plate 37 ′ fixed to the right side plate 37. Therefore, the intermediate roller driving motor 42
The intermediate roller 33 is driven to rotate, and the rotating intermediate roller 33 is rotated by the swing cam 41 by the cam follower 44.
By swinging along, a swinging motion is performed in the axial direction.

The nip pressure adjusting means 34 includes an intermediate roller 33
If the amount of dampening water cannot be adjusted sufficiently with only the rotation speed of
For example, it is used when a large amount of fountain solution is required at the start of printing. The nip pressure adjusting means 34 is provided in the bearing 3
5, a rotating shaft 47 having gears 45 and 46 fixedly engaged therewith, a motor 48 for driving the rotating shaft 47, a worm gear 49 for transmitting the driving of the motor, and a worm wheel 50. , And a set of intermediate gears 51 combined vertically. In the nip pressure adjusting means 34, the bearings 3 and 4
When the rollers 5 and 36 are rotated, the axis of the water source roller 31 is eccentric, and the nip pressure with the intermediate roller 33 can be adjusted.

In the present embodiment, since the intermediate roller 33 is driven, no driving means is connected to the water roller 31, so that the water roller 31 can be easily moved. I have. Further, in the case where the nip pressure is adjusted by eccentrically rotating the rotation axis of the water roller 31, a simpler structure than other structures such as linearly sliding the rotation axis of the water roller 31 can be employed. Further, since the nip pressure is adjusted by the motor 48, the nip pressure can be easily changed even during the operation.

A slit plate 52 is fixedly provided at the shaft end of the rotary shaft 47 so that a sensor 53 can detect the position of the slit. This is to determine the origin position for the nip pressure adjustment. Thus, even when the upper part of the dampening solution supply means 14 is removed between the intermediate gears 51 for maintenance, the origin position of the nip pressure adjustment can be determined.

Next, the procedure for adjusting the dampening solution by the nip pressure will be described with reference to FIG. FIG. 5 is a flow chart showing a procedure for adjusting the dampening solution in the printing operation after the plate making operation is completed.

In the figure, first, in step S1, the control means 7 controls the nip pressure adjusting means 34 to adjust the nip pressure to the first nip pressure. The first nip pressure is set to a nip pressure lower than a general value so that a large amount of dampening solution can be supplied. As an actual operation, the motor 48 is driven to decenter the rotation axis of the water roller 31 in a direction away from the intermediate roller 33. It is assumed that the nip pressure is previously obtained experimentally as the eccentric amount and is stored in a memory (not shown) in the control means 7.

In step S2, the control means 7 sets one of the number of prints, the number of print revolutions, and the print time (printing apparatus operation time) in an internal counter. The counter is counted based on a detection signal from a sensor (not shown) for detecting the passage of the printing paper, a rotary encoder provided on each cylinder, or the like. In the following embodiments, the number of prints is set on a counter.

In step S3, the supply of the initial dampening solution before the actual printing, the ink filling, and the like are performed. For example, in a state where the blanket cylinder 16 is removed from the plate cylinder 10 and the impression cylinder 17, dampening water and ink are continuously and continuously supplied to the printing plate on the plate cylinder 10 in advance. If necessary, the ink image may be transferred from the ink cylinder 10 to the blanket cylinder 16 several times.

In step S4, printing is actually started using printing paper. As described above, the dampening solution is supplied more than usual at the beginning of printing, including the initial dampening solution supply operation of Step 3.

Then, in step 5, the aforementioned step S2
Check the counter set in step 4 to determine whether the number of prints has reached a predetermined count. If the count has reached the predetermined count, step S8
Otherwise, the process proceeds to step S6. In addition, the above-mentioned count number is obtained in advance by a test according to the type of printing plate or ink.

In step S6, it is determined whether or not the printing operation has been completed based on, for example, the number of sheets printed on the counter. If it is determined that the printing operation has been completed, the process proceeds to step S7, where the printing operation is terminated. If it is determined that the printing operation has not been completed, the printing operation continues and the process returns to step S5.

When the process proceeds to step S8 in step S5, the control means 7 controls the nip pressure adjusting means 34 to change to the second nip pressure. The second nip pressure is a nip pressure larger than the first nip pressure. As a result, the supply amount of the dampening solution can be returned to the normal amount that is lower than the initial amount of printing. In this embodiment, only the adjustment of the nip pressure is described in steps S1 and S8, but the rotation speed of the intermediate roller may be changed at the same time.

As described above, in the above embodiment, the dampening solution is excessively supplied before the number of printed sheets reaches the predetermined count, and when the count reaches the predetermined count, the dampening solution amount is reduced to the normal value. Therefore, even if the printing plate requires a large amount of dampening solution at the beginning of printing, sufficient dampening solution can be supplied in a short time.

The count number may be set as the number of scraps for test printing. In other words, the amount of dampening solution supplied may be increased during test printing on the waste paper. Extremely, the count may be set to zero, and a large amount of dampening solution may be supplied only in the printing preparation stage (step S3) before printing is actually started.

Further, in the present embodiment, the intermediate roller 33
Although the number of rotations of the water roller 31 is controlled by controlling the driving of the roller, the water roller may be directly driven.

[0051]

According to the first and second aspects of the present invention, the nip pressure between the intermediate roller and the water source roller can be adjusted during the printing operation, so that a large amount of dampening water is required at the beginning of printing. Can be easily handled.

According to the third aspect of the present invention, since the nip pressure is adjusted by the eccentricity of the rotating shaft, the structure of the apparatus can be simplified.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a printing apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram of the printing apparatus.

FIG. 3 is a side view of a dampening solution supply unit in the printing apparatus.

FIG. 4 is a top view of the dampening solution supply means.

FIG. 5 is a flowchart showing a procedure for adjusting dampening water by the dampening water supply means.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st printing unit 2 2nd printing unit 3 paper feed part 4 intermediate conveyance part 5 paper discharge part 6 print drive part 7 control means 10 plate cylinder 11 supply / discharge plate means 12 image supply means 13 developing means 14 dampening water supply means 15 Ink supply means 16 Blanket cylinder 17 Impression cylinder 30 Water boat 31 Water source roller 32 Watering roller 33 Intermediate roller 34 Nip pressure adjustment means 35, 36 Bearing 41 Swing cam 42 Intermediate roller drive motor 44 Cam follower 45, 46 Gear 47 Rotating shaft 48 Motor 49 Worm gear 50 Worm wheel

Claims (3)

[Claims] A fountain roller partially immersed in a watercraft for storing dampening water; an intermediate roller in contact with the fountain roller;
A dampening water supply device having a dampening roller that receives dampening water from the intermediate roller and supplies dampening water to the printing plate on the plate cylinder, wherein a nip pressure between the water source roller and the intermediate roller is reduced. A dampening water supply device comprising: a nip pressure adjusting means that can be changed; and a control means that controls the nip pressure adjusting means so as to change the nip pressure during a printing operation. 2. The method according to claim 1, wherein the control means adjusts the nip pressure to a first nip pressure before the start of the operation, and any one of the number of prints, the number of rotations of the printing apparatus, and the operation time has passed a predetermined value. The dampening water supply device according to claim 1, wherein the nip pressure adjusting means is controlled to adjust the nip pressure to a second nip pressure higher than the first nip pressure. 3. The nip pressure adjusting means comprises: an eccentric bearing means for eccentrically supporting at least one of the water roller and the intermediate roller; and a rotating means for rotating the eccentric bearing means. 3. The fountain solution supply device according to 1 or 2.