JP2008018608A - Method for cleaning printing plate cylinder of printer, program and printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for cleaning a printing plate cylinder of a printer capable of rapidly execute a required printing after starting printing by preventing an inconvenience caused by a cleaning liquid remained on a printing plate cylinder from occurring, a program and a printer. <P>SOLUTION: The method for cleaning the printing plate cylinder of the printer removes ink staining on the peripheral face of the printing plate cylinder after printing process is executed in the printer equipped with an ink feeding means for feeding the ink on the printing plate cylinder. The method comprises an ink feeding stopping step for stopping feeding of the ink on the printing plate cylinder from the ink feeding means, and an ink removing step for removing the ink staining sticking to the printing plate cylinder by operating the printer under a condition that feeding of the ink is stopped by the ink feeding stopping step, and passing printing sheets by a specified number of sheets of printing set in advance through. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a printing cylinder cleaning method for a printing press that removes ink stains attached to a printing cylinder such as a plate cylinder and a blanket cylinder, a program for executing the method, and a printing machine.

  The offset printing press includes an ink supply device (also called an inker), a plate cylinder on which a printing plate is mounted, and a blanket cylinder (rubber cylinder). Ink is supplied from the inker to the plate cylinder, and the blanket cylinder is temporarily supplied from the plate cylinder. Printing is performed by transferring the ink from the blanket cylinder to the printing sheet after the ink is transferred to the peripheral surface as an ink halftone dot corresponding to the printed pattern on the printing plate.

In such an offset printing machine, when printing is finished and the printing plate is replaced with the next printing plate and printing is performed again, the blanket is used to remove stains such as ink adhering to the blanket cylinder during the previous printing. The torso needs to be cleaned.
As a method of cleaning the blanket cylinder, conventionally, a cleaning solution is applied to the peripheral surface of the blanket cylinder to easily decompose and dissolve the ink and the like, and the ink is stained on the peripheral surface of the blanket cylinder with a damp cloth. A method of wiping off the water has been proposed and put into practical use.

For example, Patent Document 1 discloses a technique for cleaning the peripheral surface of a rubber cylinder by a cleaning unit that feeds a cleaning cloth impregnated with a cleaning liquid.
JP 2002-059089 A

However, as described above, the method of wiping the peripheral surface of the blanket cylinder with the cleaning liquid cannot completely wipe the cleaning liquid used for cleaning the blanket cylinder. The cleaning liquid used for the cleaning work remains.
In this way, when the printing plate is replaced with the cleaning liquid remaining in the blanket cylinder and printing is started again, the cleaning liquid remaining on the peripheral surface of the blanket cylinder is transferred from the blanket cylinder to the ink roller in the plate cylinder or further upstream in the inker. This is a cause of hindering the transfer of ink in the inker, the plate cylinder and the blanket cylinder. Of course, the cleaning liquid is also transferred from the blanket cylinder to the printing sheet, and this may cause the transfer of ink from the blanket cylinder to the printing sheet.

For this reason, when the printing is started again after the blanket cylinder is cleaned, a desired amount of ink is not transferred to the printing sheet for a while after the printing is started, and printing from the start of printing until a printing sheet having a desired color tone is obtained. A large amount of waste paper is generated at the time of start-up, which is a factor such as an increase in printing time and a decrease in cost performance.
In particular, when the number of printed copies is a small lot (for example, about 1,000 copies or less), the ratio of waste paper to the number of printed copies of the product increases, so the productivity is significantly reduced. However, in recent years, there has been a growing need for proofreading of this machine that prints color proofs for clients on a printing machine that actually prints products, and a very small lot (for example, about several to several tens of parts) The number of cases of printing is increasing.

  The present invention has been devised in view of such problems, and prevents the ink transfer from being inhibited by the cleaning liquid adhering to the peripheral surfaces of the printing cylinders such as the plate cylinder and the blanket cylinder, so that the desired printing can be performed promptly after the start of printing. It is an object of the present invention to provide a printing cylinder cleaning method and program for a printing press and a printing press capable of performing printing.

  In order to achieve the above-mentioned object, the printing cylinder cleaning method of the present invention according to claim 1 is characterized in that, after performing a printing process in a printing machine provided with an ink supply means for supplying ink to the printing cylinder, A printing cylinder cleaning method for a printing press that removes ink stains on a peripheral surface of a printing cylinder, comprising: an ink supply blocking step for blocking supply of ink from the ink supply means to the printing cylinder; and an ink supply blocking step. An ink removing step of removing the ink stains adhering to the printing cylinder by operating the printing machine in a state where the supply of ink is cut off and passing a print sheet by a predetermined number of prints; It is characterized by having.

Particularly in the case of a sheet-fed printing press, there is a great demand for printing a very small lot for proofreading (for color proofing), and this is effective in improving the printing work efficiency.
According to a second aspect of the present invention, there is provided a printing cylinder cleaning method for a printing press of the present invention according to the first aspect, wherein the ink removal is performed on the condition that the number of printed sheets in the printing step is equal to or less than a preset cleaning condition number. It is characterized by executing steps.

A printing cylinder cleaning method for a printing press according to a third aspect of the present invention is the printing cylinder cleaning method according to the first or second aspect, wherein the number of printed sheets printed in the printing step is larger than the number of cleaning conditions. A printing cylinder cleaning step is performed in which the cleaning liquid is supplied to clean the printing cylinder.
In other words, when the number of printed sheets at the time of the previous printing is more than a predetermined number (the number of cleaning conditions), the ink adhering to the printing cylinder is dried by printing for a relatively long time, or the pigment in the ink is removed from the surface of the printing cylinder. Although it is considered that it is difficult to peel off from the printing cylinder due to entering into fine irregularities, etc., at this time, the ink stain is not removed by the ink removing step without using the cleaning liquid (Claim 2), and the printing cylinder using the cleaning liquid is used. The ink adhering to the ink can be reliably washed (Claim 3).

A printing cylinder cleaning method for a printing press according to a fourth aspect of the present invention is the printing cylinder cleaning method according to any one of the first to third aspects, wherein the printing press supplies dampening water to the printing cylinder. And a dampening water supply blocking step for blocking dampening water supply by the dampening water supply means.
The dampening water supply cutoff step may be executed before the ink supply cutoff step is executed, or may be executed after the ink supply cutoff step is executed. Further, the dampening water supply cutoff step and the ink supply cutoff step may be executed in parallel.

A printing cylinder cleaning method for a printing press according to a fifth aspect of the present invention is the printing cylinder cleaning method according to any one of the first to fourth aspects, wherein the number of cleaning conditions is a printing time, a type of ink, It is characterized in that it is set based on either the type of blanket cylinder or the stroke rate of the printed pattern.
In addition, it is preferable that the larger the number of printed sheets in the printing process, the larger the number of cleaning conditions is set. In other words, the larger the number of printed sheets in the printing process, the more difficult it is to remove the ink adhering to the printing cylinder. Therefore, by passing a large number of printing sheets, the ink on the circumferential surface of the printing cylinder more reliably. Can be removed.
A printing cylinder cleaning method for a printing press according to a sixth aspect of the present invention is the printing cylinder cleaning method according to any one of the first to fifth aspects, wherein, in the ink removing step, the predetermined number of prints set in advance is It is characterized in that it is set based on any of the number of printed sheets, printing time, ink type, and blanket cylinder in the printing process.

In particular, the larger the line drawing rate of the printed pattern in the printing process, the more ink is attached to the printing cylinder, so by passing more printing sheets, the ink on the printing cylinder surface can be removed more reliably. can do.
According to a seventh aspect of the present invention, there is provided a program for causing a computer to execute the printing cylinder cleaning method for a printing press according to any one of the first to sixth aspects.
Note that a recording medium on which such a program is recorded can also be the present invention.

  The printing machine of the present invention according to claim 8 is an ink supply means for supplying ink to a printing cylinder, and an ink supply for interrupting the supply of ink from the ink supply means to the printing cylinder after performing a printing process. The printing cylinder is controlled by operating the printing machine in a state where the ink supply is cut off by the shut-off means and the ink supply shut-off means, and passing the print sheet by a predetermined number of prints. And an ink removal control means for removing ink stains adhering to the ink.

Further, the printing press of the present invention according to claim 9 is the printer according to claim 8, wherein the ink removal control means is provided on the condition that the number of printed sheets printed in the printing step is equal to or less than a preset cleaning condition number. It is characterized by carrying out ink stain removal.
A printing machine according to a tenth aspect of the present invention is the printing machine according to the eighth or ninth aspect, wherein the cleaning liquid is supplied to the printing cylinder on condition that the number of printed sheets in the printing step is larger than the number of cleaning conditions. And a printing cylinder cleaning means for cleaning the printing cylinder.

The printing press of the present invention according to claim 11 is the printing machine according to any one of claims 8 to 10, wherein dampening water supply means for supplying dampening water to the printing cylinder, and dampening water supply means. And a dampening water supply blocking means for blocking the dampening water supply.
Further, the printing press of the present invention according to claim 12 is the one according to any one of claims 8 to 11, wherein the number of cleaning conditions is the printing time, the type of ink, the type of blanket cylinder in the printing step, It is characterized in that it is set based on one of the line ratios of the printed pattern.

  Further, the printing press of the present invention according to claim 13 is the printer according to any one of claims 8 to 12, wherein, in the ink removal step, the preset predetermined number of prints is a print in the printing step. It is set based on any of the number of sheets, printing time, ink type, and blanket cylinder.

  Therefore, according to the printing cylinder cleaning method and program for a printing press and the printing press of the present invention, ink stains attached to the printing drum can be removed without using a cleaning liquid. Sometimes it is possible to prevent problems such as smearing of the printing sheet due to the ink adhering to the blanket cylinder, and at the start of printing after cleaning the printing cylinder, preventing improper transfer of the ink due to the cleaning liquid and performing desired printing promptly. be able to.

  Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 are diagrams for explaining a printing cylinder cleaning method of a printing press and a printing press using the same according to an embodiment of the present invention, and FIG. 1 is a flowchart related to the printing cylinder cleaning method of the printing press. FIG. 2 is a diagram schematically illustrating a schematic configuration of the printing press, FIG. 3 is a diagram schematically illustrating a configuration of a printing unit of the printing press, and FIG. 4 is a function focusing on a function related to cleaning of the printing cylinder. It is a block diagram.

First, the printing press of this embodiment is demonstrated using FIGS. As shown in FIG. 2, the printing machine 1 of this embodiment is a four-color offset sheet-fed printing machine capable of process color printing. Note that the printing machine 1 described as an example of this embodiment is a single-sided printing machine, but may be a double-sided printing machine, and the number of printing colors is not particularly limited.
The printing machine 1 includes a paper feeding unit 50, a paper discharge unit 51, a printing unit 52, and the like. The printing unit 52 includes inks of process colors [black ink] along a conveyance path of a printing sheet (sheet) 8. (K), indigo (c), red (m), yellow (y)], the printing units 2a, 2b, 2c, and 2d are arranged in tandem, and are sent out one by one from the paper supply unit 50. Are sequentially passed through the impression cylinders 9a to 9d and the transfer cylinders 10a to 10d to the respective printing units 2a to 2d, whereby each ink color pattern is printed in order, and the printed printing sheet 8 is discharged. It is configured to be sent to the unit 51.

In addition, a control device 20 composed of a computer or the like is provided to control the control points of each part of the printing press 1 and is connected to the printing press 1 so that the touch panel 30 can input and output to the control device 20. It is connected. The touch panel 30 has a display function for displaying an output from the control device 20 and an input function for inputting various instruction information to the control device 20.
Each printing unit 2a, 2b, 2c, 2d is configured similarly. Therefore, the printing unit 2a will be described as an example. As shown in FIG. 3, the printing unit 2a includes an ink supply device (ink supply means) 15, an inker 5, a dampening water supply device (dampening water supply means) 13, in order from the top. A plate cylinder 3, a cleaning liquid supply nozzle (cleaning liquid supply means) 11, a cleaning drum 12, a blanket cylinder 4 and the like are included.

In the ink supply device 15, an ink fountain, which is an ink supply source, is formed by the ink base roller 6 and the plurality of ink keys 7, and a gap (ink key opening) between the ink key 7 and the ink base roller 6 and rotation of the ink base roller 6. By adjusting the speed, the supply amount of ink supplied from the ink supply device 15 is adjusted.
The ink supplied from the ink supply device 15 is conveyed by successively transferring through the inker 5 including the ink calling roller 5E and a plurality of ink roller groups, and the ink forming rollers 5A to 5D, which are the most downstream ink rollers, are conveyed. To the plate cylinder 3 on which the printing plate is mounted. The ink supplied to the plate cylinder 3 is transferred to the printing sheet 8 through the blanket cylinder 4 to form a printed pattern. The plate cylinder 3 and the blanket cylinder 4 are also called printing cylinders.

  The uppermost ink calling roller 5E of the inker 5 is provided with a calling roller swinging mechanism 40 (see FIG. 4). The calling roller swinging mechanism 40 causes the ink calling roller 5E to be connected to the ink base roller 6 and the downstream ink. It swings back and forth between the rollers. Ink is supplied from the ink supply device 15 to the inker 5 side by the reciprocating swing of the ink calling roller 5E.

  The ink supplied from the ink source roller 6 to the inker 5 can be shut off by stopping the reciprocal rocking of the calling roller by the calling roller rocking mechanism 40. A state in which ink is supplied from the ink base roller 6 to the inker 5 by the calling roller swing mechanism 40 is referred to as a state in which the ink call roller 5E is attached, and a state in which ink is not supplied from the ink base roller 6 to the inker 5 The ink calling roller 5E is in a detached state.

  Each of the ink form rollers 5A to 5D is provided with an ink form roller separation mechanism (ink supply blocking means) 41 (see FIG. 4) for separating and contacting each of the ink form rollers 5A to 5D and the plate cylinder 3. When the plate cylinder 3 is in contact with the ink form rollers 5A to 5D (this is called the state where the ink form roller is attached), the ink transfer from each of the ink form rollers 5A to 5D to the plate cylinder 3 is performed. And when the plate cylinder 3 is separated from the ink form rollers 5A to 5D (this is called the state where the ink form roller is removed), the ink transfer between the ink form rollers 5A to 5D and the plate cylinder 3 is performed. Is to be blocked. The attaching / detaching operation of the ink form roller 9 is controlled based on a signal from the control device 20.

  Further, dampening water is supplied to the plate cylinder 3 from a water boat 13B in which dampening water is stored and a dampening water supply device 13 including a plurality of rollers. A watering roller separation / contact mechanism (dampening water supply blocking means) 42 (see FIG. 4), which will be described later, is provided so that the most downstream watering roller 13A and the plate cylinder 3 are in contact with each other. Then, when the plate cylinder 3 and the swim roller 13A are in contact (this is referred to as the state where the swim roller is worn), the dampening water is supplied from the swim roller 13A to the plate cylinder 3, When the plate cylinder 3 is separated from the water roller 13A (this state is referred to as the state where the water roller is removed), the supply of dampening water between the water roller 13A and the plate cylinder 3 is cut off. ing. The attaching / detaching operation of the water application roller 13A is controlled on the basis of a signal from the control device 20 in the same manner as the ink application rollers 5A to 5D.

The cleaning liquid supply nozzle 11 is installed toward the peripheral surface of the blanket cylinder 4 and supplies the cleaning liquid based on a signal from the control device 20.
A cloth or a molton is wound around the cleaning drum 12, and the cleaning drum 12 is provided with a cleaning drum attaching / detaching mechanism 43 that makes contact with the blanket cylinder 4 (see FIG. 4). The separation / contact operation of the cleaning drum 12 is performed based on a signal from the control device 20.

As shown in FIG. 4, the control device 20 is configured by a computer or a computer, and includes a printing press operation control unit 21, a cleaning liquid supply nozzle control unit 22, a roller separation / contact control unit 23, and simple cleaning execution as functional elements. A determination unit (ink removal execution determination unit) 24 and a print information acquisition unit 25 are provided.
The printing press operation control unit 21 controls the start or stop of the operation of the printing press 1, and operates and stops the printing press 1 based on input information from the touch panel 30. .

The cleaning liquid supply nozzle control unit 22 controls the supply of the cleaning liquid from the cleaning liquid supply nozzle 11, and the roller separation / contact control unit 23 includes a calling roller swing mechanism 40, an ink form roller separation / contact mechanism 41, and a water deposition roller separation / contact mechanism. 42 and the operation of each of the attachment / detachment mechanisms of the cleaning drum attachment / detachment mechanism 43 are controlled.
The simple cleaning execution determination unit 24 permits execution of simple cleaning processing of a printing cylinder (plate cylinder 3 and blanket cylinder 4) described later when a preset simple cleaning execution condition (ink removal execution condition) is satisfied. It has become.

The simple cleaning execution condition set here is that the number of prints of the previous print job is equal to or less than the preset simple cleaning execution condition print number (hereinafter referred to as the number of cleaning conditions). Conditions can be set as appropriate.
Here, the number of cleaning conditions can be determined by the operator, but is based on the printing time of the print job, the type of ink used, the type of blanket cylinder 4, and the line rate of the printed pattern of the previous print job. Is preferably determined. Note that the number of print jobs to be printed, the print job print time, the type of ink used, the type of blanket cylinder 4, and the line rate of the print pattern of the previous print job can be obtained from the print information acquisition unit 25.

  Here, the reason for setting the simple cleaning execution condition will be described. As the number of print jobs increases, the printing time becomes longer and the ink adhering to the printing cylinder dries on the peripheral surface of the printing cylinder, increasing the adhesion force of the ink to the peripheral surface of the printing cylinder, This is because when the number of printed sheets is large, it is considered that the pigment in the ink enters minute irregularities on the peripheral surface of the blanket cylinder 4 and is difficult to peel off from the peripheral surface of the printing cylinder. That is, when the simple cleaning execution condition is satisfied, it is determined that the ink attached to the blanket cylinder 4 and the plate cylinder 3 is easily peeled off, and the peripheral surfaces of the blanket cylinder 4 and the plate cylinder 3 are obtained by performing the simple cleaning process. The ink is transferred to the printing sheet 8 to clean the printing cylinder.

The predetermined number of prints of the previous print job as the simple cleaning execution condition is preferably 1000 sheets or less, and more preferably about 100 sheets. This is because, for the reason described above, if the number of prints of the previous print job increases, there is a possibility that the ink on the printing cylinder peripheral surface cannot be sufficiently removed only by the simple cleaning process described later.
The print information acquisition unit 25 performs printing including, for each print job, the pattern halftone dot area ratio (image ratio) information and the number of copies, the type of ink to be used, the sheet type of the printing sheet 8, the type of the blanket cylinder 4, and the like. Related information is acquired. The printing related information may be input to the control device 20 by an operator via the touch panel 30 or may be directly input to the control device online from a pre-press process (not shown).

A print job is a type unit of a product to be printed. Usually, a different printing plate is mounted on the plate cylinder 3 for each print job (only a printing plate of a specific ink color may be different). Here, an operation for printing a product corresponding to a print job is defined as a printing process.
Next, with reference to FIG. 1, the process flow concerning the cleaning of the printing cylinder of the present invention will be described. This flow is performed by the control device (computer) 20 by a corresponding control program. As shown in FIG. 1, first, product printing is performed in step S10.

  When the printing is completed (printing process is completed) (step S20), the process proceeds to step 30. In step S30, it is determined whether or not to perform end processing. If there is no next print job, end processing is performed in step S100. Here, the termination process is a process performed at the end of the day, for example, and is performed when the printing press is stopped for a long time by washing ink in the ink fountain or the inker 5. is there.

In step S30, when the end process is not performed (that is, when there is a next print job), the ink calling roller 5E is removed in step S35, and the process proceeds to step S40. In step S40, a process called a print reduction process is performed.
The printing reduction process is formed on the circumferential surface of the ink roller in the inker 5 at the time of printing the previous print job for the purpose of accurately performing preliminary ink supply control (control in step S90 described later) performed prior to printing. In this process, the ink film thickness is reduced to the reference minimum film thickness.

Specifically, the ink form rollers 5A to 5D and the water form roller 13A are in a worn state, and the cleaning drum 12 is in a detached state. In this state, the printing press operation control unit 21 performs a normal printing operation for a predetermined number of prints.
As a result, the ink in the inker 5 is supplied to the printing sheet via the plate cylinder 3 and the blanket cylinder 4 and consumed, while no new ink is supplied in the inker 5, and the ink film thickness in the inker 5 is increased. The film thickness can be reduced to the reference minimum film thickness.

  In step S50, the ink separation roller separation / contact mechanism (ink supply blocking means) 41 causes the ink deposition rollers 5A to 5D to be in a detached state by the roller separation control unit 23 (ink supply blocking step). At the same time, the swim roller is removed. In step S60, the simple cleaning execution determination unit 24 determines whether or not the simple cleaning execution condition is satisfied. Specifically, the simple cleaning execution determination unit 24 determines that the simple cleaning execution condition is satisfied when the number of print jobs in the print job is equal to or less than the number of cleaning conditions.

If it is determined in step S60 that the simple cleaning execution condition is satisfied, a simple cleaning process for the printing cylinder is executed in step S70.
In the simple cleaning process, the printing press operation control unit 21 passes the printing sheet 8 by a predetermined number of cleaning printing sheets set in advance (ink removal step, ink removal control means).

That is, by performing printing in a state where the ink form rollers 5A to 5D are removed in step S50, the ink adhering to the peripheral surfaces of the plate cylinder 3 and the blanket cylinder 4 is transferred to the printing sheet 8, As a result, the ink on the plate cylinder 3 and the blanket cylinder 4 is removed.
Further, since the ink forming rollers 5A to 5D and the ink calling roller 5E are in a detached state, ink is not supplied to or consumed in the inker 5, and the ink amount on the ink roller group in the inker 5 can be kept constant. . In other words, the ink film thickness formed on the peripheral surface of each ink roller in the inker 5 can be kept constant even during execution of the simple cleaning.

  Note that the number of cleaning prints is the number of print jobs printed from the print information acquisition unit 25, the print job print time, the type of ink used, the type of blanket cylinder 4, the line rate of the print pattern of the previous print job. It may be set based on the above. For example, in general, the larger the line ratio of a printed pattern, the larger the amount of ink adhering to the circumferential surface of the blanket cylinder 4 during printing. Therefore, the larger the line ratio of the printed pattern of the previous print job, In other words, the number of print sheets 8 to pass through may be set to a large value.

In addition, the predetermined number of prints may be displayed on the touch panel 30 before the simple cleaning process is performed so that the operator can appropriately correct the predetermined number of prints.
On the other hand, if it is determined in step S60 that the simple cleaning execution condition is not satisfied, the process proceeds to step S110, and the plate cylinder 3 and the blanket cylinder 4 are cleaned using the cleaning liquid (print cylinder cleaning step, printing cylinder). Cleaning means). That is, the cleaning liquid supply nozzle control unit 22 supplies the cleaning liquid from the cleaning liquid supply nozzle 11 toward the peripheral surface of the blanket cylinder 4 and the blanket cylinder 4 and the cleaning drum 12 are put on by the roller separation control unit 23. The plate cylinder 3 is rotated to remove ink attached to the blanket cylinder 4 and the plate cylinder 3.

Thereafter, in step S120, the cleaning liquid is transferred to the printing sheet and removed by passing the printing sheet 8 by the number of cleaning liquid removal sheets necessary for removing the cleaning liquid remaining in the blanket cylinder 4. The number of cleaning liquid removed is stored in the control device 20 in advance.
In step S80, the printing plate for the previous print job attached to the plate cylinder 3 is replaced with the printing plate for the next print job.

Thereafter, preliminary ink supply is performed in step S90. When this preliminary ink supply is performed, the ink calling roller 5E is set to be worn. Preliminary ink supply is a predetermined amount corresponding to the line rate of the printed pattern printed on the ink roller group in the inker 5 in advance for the purpose of quickly changing the color tone of the pattern on the printing sheet 8 to the desired color tone after the start of printing. It is the process which forms the ink film of a film thickness. The ink preliminary supply may be performed by a known method. In the simplest case, the controller 20 stores the ink key opening and the number of rotations of the plate cylinder 3 in accordance with the image line ratio, and the roller separation control unit 23. Thus, the ink source roller 6 and the inker 5 in the inker 5 are rotated a predetermined number of times at a predetermined ink key opening stored in the control device 20 with the ink calling roller 5E and the ink form rollers 5A to 5D removed. What is necessary is just to rotate each ink roller in the inside.
When the preliminary ink supply is performed in step S90, the process returns to step S10 and printing is performed.

  Since the printing cylinder cleaning method, printing cylinder cleaning apparatus, and printing press of a printing press according to an embodiment of the present invention are configured in this manner, the cleaning liquid is not used when the number of printed copies of the previous print job is small. By this simple cleaning process, the ink adhering to the plate cylinder 3 and the blanket cylinder 4 can be sufficiently removed, and it is possible to prevent the cleaning liquid from remaining on the printing cylinder or the like. For this reason, when performing the printing of the next print job, the inhibition of ink transfer by the cleaning liquid remaining in the printing cylinder can be suppressed, and the waste paper generated from the start of printing until the print sheet 8 having a desired color tone is obtained is greatly reduced. Can be reduced. Further, the time required for the color tone adjustment work can be greatly shortened.

  That is, when the number of print copies of the print job is small, the time required for printing is shortened, and the ink is dried on the peripheral surface of the blanket cylinder 4 and fixed to the peripheral surface of the blanket cylinder 4, or the ink pigment is transferred to the blanket cylinder 4. Since printing of a print job is completed before it becomes difficult to remove ink due to being pushed into the unevenness of the peripheral surface, ink can be sufficiently removed by a simple cleaning process that does not use cleaning liquid when moving to the next print job. Can be removed.

  Accordingly, the time required for the print preparation work (print job switching work) from the end of printing of one print job to the printing of the next print job can be shortened. When a plurality of types of print jobs having a very small number of copies such as proof printing (usually about 5 to 50 copies) are continuously printed, the work efficiency can be improved.

  In the printing reduction process (step S40), the ink calling roller 5E is removed, and the ink rollers 5A to 5D are put on and the ink roller group and the printing cylinder are rotated to rotate the ink roller group. When the ink film thickness is lowered to the reference minimum film thickness and then the simple cleaning is performed (step S70), the simple cleaning is performed with the ink form rollers 5A to 5D being removed. The amount of ink on the ink roller group can be kept constant without changing (decreasing), and a desired ink film thickness can be achieved at an early stage in the subsequent preliminary ink supply (step S90).

  Further, when the simple cleaning execution condition is not satisfied, for example, when the number of copies of the previous print job is large, that is, after the ink is dried and fixed on the blanket cylinder 4, or the ink pigment is on the blanket surface. After being pushed into the irregularities, it becomes difficult to remove the ink, and the cleaning liquid can be supplied to the blanket cylinder 4 and removed by ink cleaning with a cloth or molton on the peripheral surface of the cleaning drum 12 (step S110).

  That is, by supplying the cleaning liquid to the blanket cylinder 4 and cleaning it, the ink can be reliably removed even in a state where it is difficult to remove by the simple cleaning process (step S70). That is, it is possible to select whether to perform the simple cleaning process (step S70) or the printing cylinder cleaning (step S110) based on the state of the ink on the blanket cylinder 4 or the number of prints immediately before, and the efficiency. The print job can be switched well.

  Further, after the ink stain on the circumferential surface of the printing cylinder is cleaned and removed using the cleaning liquid, the printing operation is performed for the predetermined number of cleaning liquid removal sheets to pass the printing sheet 8 (step S120). The cleaning liquid adhering to the peripheral surface can be removed from the peripheral surface of the printing cylinder by being transferred to the printing sheet 8. Thereby, the remaining amount of the cleaning liquid remaining on the peripheral surface of the printing cylinder at the time of printing the next print job can be reduced.

  At this time, since the ink form rollers 5A to 5D are in a detached state, the ink is not supplied from the inker 5 to the printing cylinder, and only the cleaning liquid remaining on the peripheral surface of the printing cylinder by passing the printing sheet 8 passes through. It can be removed efficiently, the inhibition of ink transfer by the cleaning liquid remaining in the printing cylinder at the start of printing can be suppressed, and the amount of waste paper generated from the start of printing until the printing sheet 8 having a desired color tone is obtained is greatly reduced. be able to.

For this reason, in the present embodiment, the number of print sheets 8 required for cleaning liquid removal and the next printing are compared with the number of damaged sheets generated when printing is performed with the cleaning liquid remaining in the printing cylinder as in the prior art. It is possible to reduce the amount of lost paper combined with the number of damaged paper generated after the start of job printing.
In addition, it is possible to prevent inconveniences such as the cleaning liquid being transferred from the peripheral surface of the printing cylinder to the inker 5 side and inhibiting the transfer of ink inside the inker 5.

  In addition, by setting the predetermined number of prints when performing the simple cleaning process based on the number of copies of the previous print job and the line ratio of the previous print job, the amount corresponding to the amount of ink adhering to the peripheral surface of the printing cylinder There is an advantage that the ink on the circumferential surface of the printing cylinder can be transferred to the number of printing sheets, and ink stains on the circumferential surface of the printing cylinder can be more reliably removed.

[Modification]
Here, a modified example of the above-described embodiment will be described. In the above embodiment, when the simple cleaning (step S70) is performed, the ink on the blanket cylinder 4 is transferred to the printing sheet 8 and removed by passing the printing sheet 8 by a predetermined number of cleaning sheets. When the simple cleaning is performed, the blanket cylinder 4, the impression cylinders 9a to 9d, and the transfer cylinders 10a to 10d are rotated without passing the printing sheet 8 for a predetermined period after the simple cleaning is started. May be transferred to the impression cylinder and then passed through the printing sheet 8.

Similarly, in the process of removing the cleaning liquid remaining in the blanket cylinder 4 (cleaning liquid removal process) (step S120), the blanket cylinder 4 and the pressure are not passed through the printing sheet 8 for a predetermined period after the start of the cleaning liquid removal. The printing sheets 8 may be passed after the cylinders 9a to 9d and the transfer cylinders 10a to 10d are rotated to transfer the ink on the blanket cylinder to the impression cylinder.
That is, immediately after the start of processing, a part of the ink or the cleaning liquid on the blanket cylinder 4 is transferred to the impression cylinder, whereby the amount of ink on the blanket cylinder decreases. Thereafter, by passing the paper, the ink or the cleaning liquid remaining in the blanket cylinder 4 is transferred to both sides of the printing sheet, so that the number of printing sheets 8 used in the simple cleaning and cleaning liquid removal processing can be reduced. . Further, as the printing sheet can be reduced, it is possible to reduce the execution time of the simple cleaning and the cleaning liquid removing process.

[Others]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, an explanation has been given by taking an example of a four-sided offset sheet-fed printing press as an example. However, for example, the present invention may be applied to an offset rotary press that performs printing on continuous paper. The printing method and the number of printing colors are not limited to this and can be variously applied.
In the embodiment, the dampening water supply device and the dampening roller separation / contact mechanism are provided. However, when the present invention is applied to a printing machine that does not use water during printing, the dampening water supply device is naturally used. The swim roller can be omitted.

In the above-described embodiment, when the preset simple cleaning execution condition is not satisfied, the printing cylinder is washed with the cleaning liquid without performing the simple cleaning process. Whether to perform the cleaning may be selected by the operator's judgment regardless of the simple cleaning execution condition.
Further, in the embodiment, the so-called wiping type printing cylinder cleaning provided with the cleaning drum as the printing cylinder cleaning means is performed, but a cleaning liquid jet type cleaning apparatus may be used without the cleaning drum. However, in view of the cleaning performance and the cost of the apparatus, the wiping type cleaning apparatus is preferable.

It is a figure for demonstrating the printing cylinder cleaning method of the printing press concerning one Embodiment of this invention, and is a flowchart which shows the flow of printing cylinder cleaning control of a printing press. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram for explaining a printing cylinder cleaning method for a printing press according to an embodiment of the present invention, and schematically showing a schematic configuration of the printing press. It is a figure for demonstrating the printing cylinder cleaning method of the printing press concerning one Embodiment of this invention, and is a figure which shows typically the structure of the printing unit of a printing press. It is a figure for demonstrating the printing cylinder cleaning method of the printing press concerning one Embodiment of this invention, and is a functional block diagram which paid its attention to the function concerning the cleaning of a printing cylinder.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printing machine 2a-2d Printing unit 3 Plate cylinder 4 Blanket cylinder 5 Inker 5A-5D Inking roller 6 Ink former roller 7 Ink key 8 Printing sheet 9a-9d Impression cylinder 10a-10d Transfer cylinder 11 Cleaning liquid supply nozzle (cleaning liquid supply means)
DESCRIPTION OF SYMBOLS 12 Washing drum 13 Dampening water supply apparatus 13A Swim-on roller 13B Water boat 15 Ink supply apparatus 20 Control apparatus 21 Printing machine operation control part (ink removal control means)
22 Cleaning liquid supply nozzle control unit 23 Roller separation / contact control unit 24 Simple cleaning execution determination unit (ink removal execution determination unit)
25 Print Information Acquisition Unit 30 Touch Panel 40 Calling Roller Swing Mechanism 41 Ink Forming Roller Separation Mechanism (Ink Supply Blocking Unit)
42 Swim-on roller separation mechanism (dampening water supply blocking means)
43 Cleaning drum separating / attaching mechanism 50 Paper feeding part 51 Paper discharging part 52 Printing part

Claims (13)

A printing cylinder cleaning method for a printing press that removes ink stains on the peripheral surface of the printing cylinder after performing a printing step in a printing press equipped with an ink supply means for supplying ink to the printing cylinder,
An ink supply blocking step for blocking supply of ink from the ink supply means to the printing cylinder;
The ink smear that adheres to the printing cylinder by operating the printing machine in a state where the ink supply is interrupted by the ink supply interrupting step, and passing a print sheet by a predetermined number of prints set in advance. A printing cylinder cleaning method for a printing press, comprising: an ink removing step for removing the printing cylinder. 2. The printing cylinder cleaning method for a printing press according to claim 1, wherein the ink removing step is executed on condition that the number of printed sheets in the printing step is equal to or less than a preset cleaning condition number. The printing cylinder cleaning step of cleaning the printing cylinder by supplying the cleaning liquid to the printing cylinder is performed on the condition that the number of printed sheets in the printing process is larger than the cleaning condition number. Item 3. A printing cylinder cleaning method for a printing press according to Item 1 or 2. The printing press includes dampening water supply means for supplying dampening water to the printing cylinder,
The printing cylinder cleaning method for a printing press according to any one of claims 1 to 3, further comprising a dampening water supply blocking step of blocking dampening water supply by the dampening water supply means. . The number of cleaning conditions is set based on any one of a printing time, a type of ink, a type of blanket cylinder, and a line rate of a printed pattern in the printing step. A printing cylinder cleaning method for a printing press according to any one of the preceding claims. In the ink removal step, the predetermined number of prints set in advance is set based on any of the number of prints, the printing time, the type of ink, and the type of blanket cylinder in the printing step. A printing cylinder cleaning method for a printing press according to any one of claims 1 to 5. A program for causing a computer to execute the printing cylinder cleaning method for a printing press according to any one of claims 1 to 6. An ink supply means for supplying ink to the printing cylinder;
An ink supply blocking means for blocking the supply of ink from the ink supply means to the printing cylinder after performing the printing process;
Ink adhering to the printing cylinder by controlling the printing machine to pass a predetermined number of printed sheets by operating the printer in a state where the ink supply is blocked by the ink supply blocking means An ink removal control means for removing dirt. 9. The printing machine according to claim 8, wherein the ink removal control means performs the ink stain removal on condition that the number of printed sheets printed in the printing step is equal to or less than a preset cleaning condition number. . A printing cylinder cleaning unit is provided for supplying the cleaning liquid to the printing cylinder and cleaning the printing cylinder on the condition that the number of printed sheets in the printing step is larger than the cleaning condition number. Item 10. A printing machine according to item 8 or 9. Dampening water supply means for supplying dampening water to the printing cylinder;
The printing press according to any one of claims 8 to 10, further comprising dampening water supply blocking means for blocking dampening water supply by the dampening water supply means. The number of cleaning conditions is set based on any one of a printing time, a type of ink, a type of blanket cylinder, and a line drawing rate of a printed pattern in the printing step. The printing machine according to any one of the above. The predetermined number of prints set in advance in the ink control removing unit is set based on any of the number of printed sheets, the printing time, the type of ink, and the type of blanket cylinder in the printing step. The printing machine according to any one of claims 8 to 12.

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