JP2007069361A - Dampening water adjusting device on surface of ink roller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dampening water adjusting device on the surface of an ink roller, which can remove an excess dampening water in the ink film on the surface of the ink roller so as to adapt to regions, respective image area percentages of which differ from each other, of a printing plate and also as to adapt to both the inside of the range of a printing paper and to the outside of its range. <P>SOLUTION: This dampening water adjusting device on the surface of the ink roller comprises an air jetting means, which can manage the distribution of the jetting amount along the axial direction of the ink roller, a desired value computing means based on the image area percentages, a moisture content measuring means of an ink film on the surface of the ink roller, a controlling means, which performs control operation based on the moisture content and output two manipulated variables so as to conform the water contents inside the range of the printing paper and outside its range to the predetermined desired values, and a managing means of air jetting amount based on the manipulated variables. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention belongs to the technical field of offset printing presses. In particular, the surface of the ink roller that makes the amount of dampening water in the entire area of the ink roller surface an appropriate value regardless of the size in the width direction of the printing paper, the printing plate, the distribution of the image area on the printing plate, etc. The present invention relates to a dampening water adjusting device.

  In offset printing, ink is transferred from the ink transfer roller to the image area of the printing plate to form an ink film image. The imaged ink film is transferred to the blanket and then transferred from the blanket to the printing paper. To do. The name offset is derived from the fact that the printing plate and the printing paper do not come into direct contact. In order to form an image of an ink film, it is necessary to transfer ink to an image line portion of a printing plate and prevent ink from transferring to a non-image line portion. For this reason, the physical property of the image area is oleophilic to accept oil-based ink, and the physical property of the non-image area is hydrophilic to repel the ink. In a general (with water) offset printing press, dampening water is used to impart physical properties that strongly repel ink to non-image areas.

  As a method for supplying dampening water, for example, there is a method for supplying dampening water stored in a water boat to an ink roller and transferring it to a printing plate. At this time, dampening water is present in the ink film on the surface of the ink roller. Not only in this method, but also in the method of transferring dampening water directly to the printing plate, the dampening water on the plate surface and the ink roller come into contact with each other, so that the dampening water exists in the ink film. become. Therefore, the measured value of the amount of dampening water (moisture content) existing in the ink film on the surface of the ink roller reflects the supply amount of dampening water.

  The supply amount of dampening water is closely related to the printing quality. If the supply is insufficient, printing quality defects such as blurring and stencil printing will occur. Such print quality defects occur. The printing plate has different picture contents depending on the part. In a portion where the dot area ratio is large, the non-image area is small, the repulsion due to ink is strong, and it is difficult to wet, so it is necessary to supply a large amount of dampening water. In a portion where the dot area ratio is small, the non-image area is large, the repulsion by ink is weak, and it is easy to get wet, so it is necessary to supply a small amount of dampening water. That is, the appropriate amount of dampening water supplied varies depending on the portion of the printing plate. For this reason, the range of the amount of dampening water supplied to obtain an appropriate value that is acceptable in the entire area of the printing plate is often extremely narrow. When a print quality defect occurs, not only is the printing paper, ink, etc. wasted, but production is hindered due to a decrease in the operating rate of the printing press and the influence on the entire production plan.

  Therefore, it is necessary to adjust the supply amount of the fountain solution to an appropriate value so that the print quality defects do not occur. However, a general mechanism for supplying dampening water is a mechanism for supplying dampening water uniformly in the entire area of the ink roller. There is no mechanism for adjusting the supply amount in the specific region, for example, a mechanism for giving the supply amount an axial distribution. However, if there is an extreme difference in the pattern area ratio in the axial direction, it is necessary to supply a large amount of dampening water at a site where the pattern area ratio is large. There is a need to supply a small amount of water. As described above, when it becomes impossible to satisfy the conflicting needs at the same time, there is a problem that a printing quality defect occurs and printing cannot be performed. Further, even if it is barely satisfied, a large amount of dampening water is generally supplied to avoid the occurrence of poor print quality. For this reason, there is a problem in that an adverse effect due to the supply of excessive dampening water becomes obvious as the printing time elapses, resulting in poor print quality.

  In the offset printing press, the width of the printing plate that can be mounted on the plate cylinder is defined as one width. The width is determined by the width of the inking mechanism and the dampening solution mechanism. Therefore, when printing on a printing paper having a width smaller than that of the printing plate, a printing plate having a specified width is used. At that time, there is an area out of the printing area on the printing plate (an area outside the printing paper range). The dampening water supplied to the printing plate is consumed by being transferred to the blanket and further transferred to the printing paper, and the amount of dampening water (water content) in the ink film is kept constant. When the amount of supply is large, the amount of consumption increases, and when the amount of supply is small, the amount of consumption is also small and balanced. However, since the dampening water is not absorbed by the printing paper in the non-printing portion outside the printing paper range, the dampening water is excessively accumulated in the ink film. For this reason, there is a problem in that an adverse effect due to the supply of excessive dampening water becomes obvious as the printing time elapses, resulting in poor print quality.

There is an invention of an apparatus for removing dampening water contained in an ink film on the surface of an ink roller (Patent Document 1). According to the invention, the fountain solution absorbed in the ink film of the portion corresponding to the printing area of the plate mounted on the plate cylinder among the ink film on the surface of the ink roller was adjusted according to the pattern area ratio. Remove at a flow rate that does not affect ink transferability due to humidity air. However, although some of the above problems can be solved in such a conventional invention, many problems remain unsolved.
Patent No. 3303712

  The present invention has been made to solve the above problems. Its purpose is to remove excess dampening water in the ink film on the surface of the ink roller and make it appropriate, and dampening water can be removed so as to fit the parts of the printing plate with different pattern area ratios. An object of the present invention is to provide a dampening water adjusting device on the surface of an ink roller that can remove dampening water so as to fit within and out of the range of printing paper.

A dampening solution adjusting device for an ink roller surface according to claim 1 of the present invention includes an air jetting means for jetting air so that the distribution of the jetted quantity can be manipulated along the axial direction of the ink roller of the offset printing machine, and the ink roller A moisture amount measuring means for measuring the amount of moisture contained in the ink film on the surface; a control means for performing a control calculation based on the moisture amount and outputting an operation amount so that the moisture amount becomes a predetermined target value; and And an ejection amount operating means for operating the amount of air ejected by the air ejection means based on the operation amount.
A dampening water adjusting device for an ink roller surface according to claim 2 of the present invention is a dampening water adjusting device for an ink roller surface according to claim 1, wherein the dampening water adjusting device is divided by a boundary line perpendicular to the plate cylinder axis direction. A target value calculating means for calculating the target value based on the pattern area ratio which is the area of the image line portion of the plate surface area is provided.
According to a third aspect of the present invention, there is provided an ink roller surface dampening water adjusting device according to the first or second aspect of the invention, wherein the ink roller surface dampening water adjusting device is an ink for distinguishing between the inside and the outside of the printing paper. Based on the printing paper position data in the axial direction of the roller, the control means outputs two operation amounts that fit within the range and an operation amount that fits outside the range.
A dampening water adjusting device for an ink roller surface according to a fourth aspect of the present invention is the dampening water adjusting device for an ink roller surface according to any one of the first to third aspects, wherein the ink roller is disposed in the offset printing machine. Among a plurality of ink rollers, the ink roller is located closest to the plate surface of the plate cylinder and located on the paper discharge side.

According to the dampening water adjusting device for the ink roller surface according to claim 1 of the present invention, air is jetted so that the jetting amount distribution can be adjusted along the axial direction of the ink roller of the offset printing press by the air jetting means, The amount of moisture contained in the ink film on the surface of the ink roller is measured by the moisture amount measuring means, the control means performs control calculation based on the amount of moisture, and the operation amount is output so that the moisture amount becomes a predetermined target value. The amount of air ejected by the air ejecting means is manipulated by the amount manipulating means based on the manipulated variable. Accordingly, it is an object of the present invention to provide an ink roller surface dampening water adjusting device capable of removing excess dampening water in the ink film on the ink roller surface and making it appropriate.
According to the dampening solution adjusting device for the ink roller surface according to claim 2 of the present invention, the pattern area ratio which is the area of the image area of the plate surface area divided by the boundary line perpendicular to the plate cylinder axis direction Based on the above, the target value is calculated by the target value calculating means. Therefore, the fountain solution can be removed so as to match the portions of the printing plate having different pattern area ratios.
According to the fountain solution adjusting device for the surface of the ink roller according to claim 3 of the present invention, the control means uses the printing paper position data in the axial direction of the ink roller to distinguish between the inside and the outside of the printing paper. Two operation amounts are output: an operation amount that fits within the range and an operation amount that fits outside the range. Accordingly, the fountain solution can be removed so as to fit within and outside the range of the printing paper.
According to the fountain solution adjusting device for an ink roller surface according to claim 4 of the present invention, the ink roller to be blown out of air is the closest to the plate surface of the plate cylinder among the plurality of ink rollers in the offset printing machine. This is an ink roller located near the paper discharge side. Therefore, it is possible to remove excess dampening water from the ink film on the surface of the ink roller and make it appropriate, and dampening water can be removed so as to fit the parts of the printing plate with different pattern area ratios. The dampening water can be removed.

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram showing an example of the configuration of a dampening water adjusting device for an ink roller surface according to the present invention. 2 and 3 are explanatory views showing an example of the configuration of the air ejection amount adjusting section and the air ejection section in the dampening water adjusting device for the ink roller surface of the present invention.
1-3, 1 is an air supply unit, 2 is an air dryer, 3 is an air ejection amount operation unit, 31a, 31b,... Are lids, 32a, 32b,. ... Jetting section, 41 is a large diameter pipe, 42 is a small diameter pipe, 43a, 43b,... Are jet nozzles, 44a, 44b,. , 101 is an ink roller, 102 is a plate cylinder, 103 is a blanket cylinder, 104 is an ink fountain, 105 is a water boat, and 200 is printing paper.

  The ink fountain 104 is constituted by an ink blade, an adjustment key, an ink take-out roller 141, and the like, and is a portion for storing ink in a printing machine. The ink stored in the ink fountain 104 is fed from the gap between the ink blade and the ink ejection roller 141 by the rotation of the ink ejection roller 141, and forms an ink film on the peripheral surface of the ink ejection roller 141. The adjustment keys are for adjusting the size of the gap, and a plurality of adjustment keys are arranged in the axial direction of the ink discharge roller 141. The size of the gap is determined to give a distribution of the required amount of ink related to the size of the pattern area ratio in the printing plate. The ink formed on the peripheral surface of the ink discharge roller 141 is transferred to the ink mixing roller by the ink transfer roller that reciprocally moves between the ink discharge roller 141 and the ink mixing roller and makes intermittent contact. Then, after passing through a plurality of kneading rollers, the ink roller (ink forming roller) 101 is reached.

  The water boat 105 is a part for storing dampening water. The fountain solution is supplied to the water fountain 105 by a pump from a fountain solution storage tank in which the amount, temperature, etc. of the additive are controlled, and the fountain solution overflowed in the water fountain 105 is returned to the storage tub. It has become. With the configuration in which the fountain solution is circulated, the composition, temperature, liquid level, and the like of the fountain solution are maintained at appropriate values. The fountain solution is supplied from the water boat 105 onto the ink film on the surface of the ink roller via several types of fountain solution rollers. The fountain solution reaches the ink roller 101 via a plurality of ink rollers. In the meantime, the ink is kneaded, and the fountain solution is not only present on the ink film but also mixed with the ink (emulsified state). Then, the fountain solution is supplied together with the ink from the ink roller 101 to the plate surface of the printing plate mounted on the plate cylinder 102.

On the printing plate, an ink film is formed on the image area. On the other hand, the ink is strongly repelled in the non-image area to retain the fountain solution, and no ink film is formed. The ink film on which the printing pattern is formed on the printing plate is transferred to the blanket cylinder 103 and further transferred to the printing paper 200 for printing. The fountain solution in the non-image area on the printing plate is also transferred to the blanket cylinder 103 and further transferred to the printing paper 200 and absorbed and consumed.
On the other hand, when the width of the printing paper 200 is narrower than the width of the printing plate, the dampening water in the region protruding from the printing paper 200 is not absorbed by the printing paper 200. Therefore, the water on the plate surface is in an excessive supply state.

The dampening water adjusting device for an ink roller surface according to the present invention jets air to the ink roller 101 in the offset printing machine as shown in FIG.
The air supply unit 1 generates pressurized air (pressurized air) from atmospheric pressure air, and finally air is ejected through several parts such as an air dryer 2 and an air ejection amount operation unit 3. Pressurized air is supplied to the unit 4. As the air supply unit 1, a well-known air compressor (compressor), blower, fan, or the like can be used.
The air dryer 2 generates dry air (pressurized dry air) by removing moisture (humidity) contained in the pressurized air supplied from the air supply unit 1. By using dry air, the fountain solution contained in the ink film can be efficiently volatilized.

  The air ejection amount operation unit 3 generates air (pressure drying operation air) in which the ejection amount is adjusted from the pressure drying air supplied from the air dryer 2. The air ejection amount operation unit 3 inputs an operation amount (described later) output from the control unit 7 and operates the air ejection amount in the air ejection unit 4 based on the operation amount. The air ejection amount operation unit 3 operates the distribution of the ejection amount along the axial direction of the ink roller 101 when the air ejection unit 4 ejects air. That is, the operation amount includes an operation amount related to the distribution of the ejection amount, and the air ejection amount operation unit 3 has a mechanism for operating the distribution of the ejection amount. Naturally, when the amount of ejected air is large, the volatilization rate of the dampening water contained in the ink film is high, and when the amount of air ejected is small, the volatilization rate of the dampening water contained in the ink film is low.

  The air ejection part 4 ejects air so that the distribution of the ejection amount can be manipulated along the axial direction of the ink roller 101. Among the ink rollers that are present in the offset printing machine, the ink roller that is the target from which the air ejection unit 4 ejects air is the ink roller that is closest to the plate surface of the plate cylinder and is located on the paper discharge side. For example, as shown in FIG. 2, the ink roller 101 is an ink form roller that is in contact with the plate surface of a printing plate and supplies ink and dampening water. As a result, excess dampening water in the ink film on the surface of the ink roller can be removed and adjusted appropriately, and dampening water can be removed so as to conform to parts of the printing plate with different pattern area ratios. The dampening water can be removed efficiently.

  An example (part 1) of the air ejection amount operation unit 3 and the air ejection unit 4 is shown in FIG. As shown in FIG. 2, the air ejection portion 4 has a form in which a small diameter pipe 42 is inserted and coupled to the inside of a large diameter pipe 41. The inserted portion is not fixed, and the small-diameter pipe 42 can be pushed into and pulled out from the large-diameter pipe 41. That is, the effective width of the air ejection part 4 can be adjusted. Pressurized dry air is supplied from the air dryer 2 to the large diameter pipe 41 and the small diameter pipe 42. The large diameter pipe 41 and the small diameter pipe 42 are provided with a plurality of ejection holes 43a, 43b,... Arranged in the axial direction of the pipe. The pressurized dry air supplied from the air dryer 2 to the large-diameter pipe 41 and the small-diameter pipe 42 is ejected from the ejection holes 43a, 43b,. That is, the air ejection part 4 is constituted by the large diameter pipe 41 and the small diameter pipe 42.

  2, the large-diameter pipe 41 and the small-diameter pipe 42 are provided with a plurality of lids 31a, 31b,... Arranged in the axial direction of the pipe. The lids 31a, 31b,... Are lids for opening and closing the ejection holes 43a, 43b,. Each of the lids 31a, 31b,... Is attached with a drive mechanism (not shown) for inputting an operation amount and opening / closing them. The ejection holes 43a, 43b,... Can be opened and closed by opening and closing the lids 31a, 31b,. By selecting the lid to be opened and closed, the distribution of the air ejection amount and the ejection amount in the axial direction of the pipe can be arbitrarily controlled. That is, the air ejection amount operation unit 3 is configured by the lids 31a, 31b,.

  An example (part 2) of the air ejection amount operation unit 3 and the air ejection unit 4 is shown in FIG. As shown in FIG. 3, the air ejection part 4 is comprised by several independent nozzle 44a, 44b, .... The plurality of nozzles 44a, 44b,... Are arranged on a straight line at substantially equal intervals. The direction of the straight line is parallel to the axial direction of the ink roller 101. The pressure drying operation air is supplied to the nozzles 44a, 44b,.

  Moreover, as shown in FIG. 3, as for the air ejection amount operation part 3, the solenoid valves 32a, 32b, ... are provided in each of these nozzles 44a, 44b, .... The solenoid valves 32a, 32b,... Perform the opening / closing operation of the valves by inputting the operation amount. By selecting the solenoid valve to be opened and closed, the amount of air ejection and its distribution in the nozzles 44a, 44b,... Can be arbitrarily manipulated. That is, the air ejection amount operation unit 3 is configured by the electromagnetic valves 32a, 32b,.

  The moisture amount measuring unit 5 measures the amount of moisture contained in the ink film on the surface of the ink roller 101. A known moisture measuring device can be used as the moisture measuring unit 5. For example, the electrical resistance of printing ink changes greatly depending on the amount of moisture (water content), and the charged charge retention function also changes in the same manner. Therefore, the amount of moisture can be determined by measuring the charging potential (Japanese Patent Laid-Open No. 8). -54371). The moisture amount measuring unit 5 may be configured to measure one place in the ink film of the ink roller 101. At that time, the increase / decrease in the moisture content in other parts is predicted and calculated by the increase / decrease in the moisture content in that part (described later). Further, the moisture amount distribution in the axial direction of the ink roller 101 can be measured. For example, the detector of the moisture amount measuring unit 5 is provided at a plurality of locations, or the detector is scanned in the axial direction of the ink roller 101. At that time, it is possible to measure the distribution of water content as an actual measurement value.

  The calculation unit 6 performs all necessary data processing except for data processing (for example, control calculation in the control unit 7 and the like) performed in other parts of the dampening water adjusting device for the ink roller surface of the present invention. For example, the calculation unit 6 includes a display, a keyboard, a mouse, and the like. Then, a user interface with the operator is provided for setting operation conditions, displaying operation states, and the like. In addition, data is transmitted to and received from an external device via a network such as a LAN. Moreover, the process which sets the operating condition with respect to the control part 7 is performed. Further, a program for the overall operation (see FIG. 4) of the dampening water adjusting device on the surface of the ink roller is stored, and the program is executed. The calculation unit 6 can be realized by software and hardware in a data processing device such as a personal computer.

  In addition, the calculation unit 6 inputs the measurement value of the moisture content output from the moisture content measurement unit 5 and stores it in the memory as log data. The log data includes operating conditions and date and time set together with the amount of water. The log data can be used for data analysis for investigating the cause of defective printed matter. Further, the calculation unit 6 outputs the input measurement value of the moisture amount to the control unit 7. The output of the moisture content measurement value may be performed directly from the moisture content measurement unit 5 to the control unit 7. For example, with respect to a predetermined moisture amount (target value) set in the calculation unit 6 by the operator, the control unit 7 calculates and outputs an operation amount so that the moisture amount of the measurement value becomes the moisture amount of the target value. .

  Further, the calculation unit 6 calculates a target value of the moisture amount of the ink roller 101 based on the pattern area ratio of the printing plate (target value calculation means). When the water content measurement unit 5 is configured to measure the water content distribution, the calculation unit 6 calculates the target value of the water content distribution in the axial direction of the ink roller 101 based on the pattern area ratio of the printing plate. The pattern area ratio is the area of the image line portion of the plate surface area divided by the boundary line perpendicular to the plate cylinder axis direction. The pattern area ratio is usually calculated by a preset device based on plate making data corresponding to a printing plate. The preset is a preset of printing conditions (opening of the ink adjustment key, etc.) performed before starting printing. The calculation unit 6 inputs the pattern area ratio calculated by such a preset device via a network or the like.

  In order to obtain the relationship between the pattern area ratio and the target value by calculation, it is necessary to derive a function based on experimental data. In a general printing plate, there is a correlation between the pattern area ratio (ratio of the image line part in the band region) and the halftone dot area ratio (ratio of the image line part in the mesh image). If the halftone dot area ratio is large, the required amount of water increases. That is, when the pattern area ratio is large, the target value of the moisture amount is large. On the contrary, if the halftone dot area ratio is small, the required amount of water increases. That is, when the pattern area ratio is small, the target value of the moisture amount is small.

  In addition, as a process for setting the operation condition of the control unit 7, the calculation unit 6 outputs to the control unit 7 print sheet position data in the axial direction of the ink roller that distinguishes between the inside and the outside of the print sheet. The printing paper position data is set and input by the operator to the calculation unit 6. When the printing paper position data is output to the control unit 7 by the calculation unit 6, the control unit 7 outputs two operation amounts that are within the range and operation amounts that are outside the range. There is absorption of dampening water by the printing paper within the range of the printing paper, and no absorption outside the range. Thereby, dampening water can be removed so that it may fit in and out of the range.

The control unit 7 outputs the operation amount so that the water amount of the ink film measured by the water amount measuring unit 5 becomes the target amount of water. Based on the operation amount, the air ejection amount operation unit 3 manipulates the ejection amount of air ejected from the air ejection unit 4. Therefore, the control unit 7 outputs the number of operation amounts that matches the number of locations where the air ejection amount in the air ejection amount operation unit 3 is manipulated.
When the location where the moisture content measurement unit 5 measures the moisture content of the ink film and the location where the air ejection amount in the air ejection amount operation unit 3 operates on a one-to-one basis, the control unit 7 measured. The deviation between the moisture content at the location and the target value at that location is calculated. Then, a control calculation based on the deviation is performed, and an operation amount at a location where the ejection amount corresponding to the location where the moisture content is measured is output.

  When the location where the moisture measurement unit 5 measures the moisture content of the ink film and the location where the air ejection amount manipulation unit 3 operates the air ejection amount do not correspond one-to-one, for example, the moisture measurement unit When 5 measures the moisture content of the ink film at one location (location A), the control unit 7 calculates the deviation between the measured moisture content at one location (location A) and the target value at that location (location A). . For that location (location A), a control calculation based on the deviation is performed, and the operation amount at that location (location A) is output. For other locations (location X) where the air ejection amount is manipulated, it is estimated that there was a deviation corresponding to the target value of the other location (location X) obtained by the calculation unit 6 based on the pattern area ratio. Then, the operation amount at the other part (location X) is output. The estimated value of the deviation is calculated based on, for example, the following formula: (deviation at location X) = (deviation at location A) × ((target value at location X) / (target value at location A)).

  In addition, the water content measurement unit 5 measures the water content of the ink film at a plurality of locations, but when the location where the air ejection amount is manipulated does not correspond one-to-one, the control unit 7 measures the water content. As for the location that has been operated and the location where the ejection amount is manipulated, the location where the location is close is related. Then, the two locations associated with each other are set as the above-mentioned location A and location X, and the operation amount of the location X is output by performing the calculation as described above.

A control calculation for generating an operation amount in the control unit 7 is not particularly limited in the present invention, but a control calculation in a control method such as on / off control, proportional control, PID control, etc. provided with a general dead zone is applied. be able to.
In the on / off control, when the deviation of the location to be operated exceeds the upper limit of the dead zone, the amount of water has increased too much, so the control unit 7 determines the operation amount for turning on the air ejection. 3 is output. Also, when the deviation at that location falls below the lower limit of the dead zone, the amount of moisture has decreased too much, so the control unit 7 outputs an operation amount for turning off the air ejection to the air ejection amount operation unit 3. In the example shown in FIG. 2, the on / off control of the air ejection means that the lids 31 a, 31 b,. Further, in the example shown in FIG. 3, it means that control is performed so that the electromagnetic valves 32a, 32b,.

  In the proportional control, the control unit 7 outputs an operation amount obtained by multiplying the deviation by a predetermined coefficient to the air ejection amount operation unit 3. In PID control, the control unit 7 outputs an operation amount obtained by performing calculations including proportionality, integration, and differentiation to the deviation to the air ejection amount operation unit 3. In the example shown in FIG. 2, the proportional control of air ejection or PID control means that the lids 31a, 31b,... Further, in the example shown in FIG. 3, it means that control is performed to open the electromagnetic valves 32a, 32b,... At an opening determined by the operation amount.

  Based on the printing paper position data in the axial direction of the ink roller that distinguishes the printing paper within and outside the printing range, the control unit 7 outputs an operation amount that fits within the range and an operation amount that fits outside the range. To do. The printing paper position data is data set in the calculation unit 6 by the operator. The dampening water of the blanket cylinder 103 is absorbed by the printing paper within the range of the printing paper, but the dampening water is not absorbed outside the range. Therefore, outside the range, for example, the control unit 7 outputs a predetermined operation amount at which the supply of dampening water does not become excessive, for example, an operation amount that always sets the air ejection amount to 80% or more of the maximum amount.

  Further, the image area ratio is zero because there is no image area outside the range of the printing paper. Despite differences in the amount of fountain solution used within and outside the printing paper range, setting the same target value corresponding to a pattern area ratio of zero will result in dampening outside the printing paper range. Water supply becomes excessive. Therefore, outside the range, for example, the control unit 7 performs a control calculation under the condition that the target value outside the print paper range is lower than the target value of the portion where the pattern area ratio is zero within the print paper range. Output quantity.

The configuration has been described above. Next, the operation of the dampening water adjusting device for the ink roller surface according to the present invention will be described. FIG. 4 shows the process of operation as a flowchart.
First, in step S1 (setting input) in FIG. 4, the operator performs setting input to the dampening water adjusting device on the surface of the ink roller. Setting input is performed by a method such as input from a keyboard, downloading data via a LAN, or reading data from a portable storage medium. Items to be set and input include printing paper position data, pattern area ratio, operating conditions outside the printing paper range (air ejection amount, target value), control parameters (dead zone, proportionality coefficient, PID control parameters), log data collection Processing conditions (alarms, printing press stop), etc.

Next, in step S2 (operation start input), the operator performs input for starting operation. The dampening water adjusting device on the surface of the ink roller starts operation.
Next, in step S <b> 3 (water content measurement), the water content measurement unit 5 measures the water content in the ink film on the surface of the ink roller 101. The calculation unit 6 generates log data relating to the operation state including the moisture content and stores the log data in the memory of the calculation unit 6.
Next, in step S4 (control calculation), the control unit 7 performs a control calculation based on the measured moisture content and outputs an operation amount.

Next, in step S5 (air ejection amount operation), the air ejection amount operation unit 3 manipulates the air ejection amount based on the operation amount.
Next, in step S6 (air ejection), the air ejection part 4 ejects the operated amount of air.
Next, in step S7 (end?), The calculation unit 6 determines whether or not to end the dampening water adjustment. If not, the process returns to step S3 to repeat the subsequent processes. When there is an end command due to interruption or the like, the dampening water adjustment is ended.

It is explanatory drawing which shows an example of a structure in the dampening water adjustment apparatus of the ink roller surface of this invention. It is explanatory drawing which shows an example (the 1) of a structure of the air ejection amount adjustment part and air ejection part in the dampening water adjustment apparatus of the ink roller surface of this invention. It is explanatory drawing which shows an example (the 2) of a structure of the air ejection amount adjustment part and air ejection part in the dampening water adjustment apparatus of the ink roller surface of this invention. It is a figure which shows the process of the operation | movement in the dampening water adjustment apparatus of the ink roller surface of this invention as a flowchart.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Air supply part 2 Air dryer 3 Air ejection amount operation part 31a, 31b, ... Cover 32a, 32b, ... Solenoid valve 4 Air ejection part 41 Large diameter pipe 42 Small diameter pipe 43a, 43b, ... Spout 44a, 44b, ... Nozzle 5 Moisture content detection unit 6 Calculation unit 7 Control unit 101 Ink roller 102 Plate cylinder 103 Blanket cylinder 104 Ink fountain 105 Water boat 200 Printing paper

Claims (4)

An air ejecting means for ejecting air so that the distribution of the ejected amount can be manipulated along the axial direction of the ink roller of the offset printing machine; a moisture content measuring means for measuring the amount of moisture contained in the ink film on the surface of the ink roller; Control means for performing a control calculation based on the amount of moisture and outputting an operation amount so that the amount of moisture becomes a predetermined target value, and an ejection amount for manipulating the amount of air ejected by the air ejection means based on the amount of operation And a dampening solution adjusting device for the surface of the ink roller. 2. The dampening water adjusting device for an ink roller surface according to claim 1, wherein the target is based on a pattern area ratio which is an area of an image line portion of a plate surface area divided by a boundary line perpendicular to the plate cylinder axis direction. A dampening water adjusting device for an ink roller surface, comprising target value calculating means for calculating a value. 3. The fountain solution adjustment apparatus for an ink roller surface according to claim 1 or 2, wherein the control means is within the range based on printing paper position data in the axial direction of the ink roller that distinguishes the printing paper range from the printing paper range. A dampening water adjusting device on the surface of the ink roller, which outputs an operation amount that conforms to No. 1 and an operation amount that conforms to the outside of the range. 4. A dampening solution adjusting device for an ink roller surface according to any one of claims 1 to 3, wherein a plurality of said ink rollers are closest to a plate surface of a plate cylinder among a plurality of ink rollers in said offset printing machine. A dampening water adjusting device for the surface of an ink roller, characterized in that the ink roller is located on the surface of the ink roller.