JP2008273100A - Ink supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink supply device, in which unnecessarily great amount of ink does not stay in the ink fountain of a printing machine. <P>SOLUTION: In the ink supply device having a level sensor and a controlling means, the level sensor detects the position of an ink level in the ink fountain and outputs a positional signal and the controlling means inputs a positional signal indicating that the amount of ink jetting out to the ink fountain is zero, and calculates the ink consuming speed corresponding to the pattern area percent of a printing plate and printing speed from the changing speed of the position of the ink level, and then controls the reserve supplying amount of ink to be supplied to the ink fountain before the start of printing based on the ink consuming speed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention belongs to the technical field of printing presses. In particular, the present invention relates to an ink supply device that does not unnecessarily retain a large amount of ink in an ink fountain of a printing press.

  An ink fountain for storing ink in a lithographic printing machine is provided with an ink discharge roller, an ink blade, and an adjusting screw. The inking roller draws ink from the ink fountain by rotating. The adjusting screw adjusts a gap between the ink discharge roller and the ink blade. The ink stored in the ink fountain passes through the gap and is guided to the surface of the ink discharge roller. Therefore, the thickness of the derived ink film can be adjusted by the adjusting screw. The ink blade may be a single blade, but is often a plurality of divided blades. By adjusting the adjusting screw corresponding to each of the divided blades, the thickness distribution of the ink film in the axial direction (width direction) of the ink discharge roller can be changed. Usually, the pattern area ratio distribution (ink consumption rate distribution) of the printing plate is adjusted to match the ink film thickness distribution (ink supply amount distribution).

In general, there are few print items having a uniform pattern area ratio distribution on the entire surface, and the pattern area ratio distribution is generated in the width direction (perpendicular to the running direction of the printed matter). As a result, regions where ink consumption is fast and regions where ink consumption is slow are distributed in the ink fountain, and the ink residence time in the ink fountain is not uniform in the width direction. Conventionally, in order to reduce the work load, etc., the ink supply to the ink fountain has been automated (Patent Document 1). At this time, printing is performed by filling a large amount of ink into the ink fountain so that the ink does not run out. However, this method has the following problems a) to d) (see FIGS. 5 and 6).
a) Unnecessary ink may be supplied during printing.
b) When a large amount of ink is filled in the ink fountain, the staying ink is dried to form a film.
c) The dried ink film causes printing failure. d) The dried ink film impedes the operation of the ink key and makes it impossible to control the ink supply amount.
e) The dried ink film does not re-dissolve naturally but must be cleaned and removed.
JP 2005-35041 A

  The present invention has been made to solve the above problems. An object of the present invention is to provide an ink supply device that does not unnecessarily retain a large amount of ink in an ink fountain of a printing press.

The ink supply device according to claim 1 of the present invention has a control means for controlling the preliminary ink supply amount to be supplied to the ink fountain before the start of printing in accordance with the pattern area ratio of the printing plate. .
An ink supply apparatus according to a second aspect of the present invention is the ink supply apparatus according to the first aspect, further comprising a liquid level sensor that detects a position of the ink surface in the ink fountain and outputs a position signal, and the control means. Inputs the position signal when the amount of ink discharged to the ink fountain is zero, and the ink consumption corresponding to the pattern area ratio and printing speed of the printing plate from the change speed of the position of the ink surface after the start of printing The speed is calculated, and the ink preliminary supply amount is controlled based on the ink consumption speed.
An ink supply apparatus according to a third aspect of the present invention is the ink supply apparatus according to the second aspect, wherein the control unit collects data of the ink consumption speed according to the pattern area ratio and the printing speed of the printing plate. Then, an ink consumption speed corresponding to an arbitrary pattern area ratio and an arbitrary printing speed is calculated by linear regression calculation and applied to the control of the ink preliminary supply amount.
An ink supply apparatus according to a fourth aspect of the present invention is the ink supply apparatus according to any one of the first to third aspects, wherein a plurality of the ink discharge ports are arranged in the direction of the plate cylinder rotation axis in the ink fountain. The pattern area ratio is a pattern area ratio in each area obtained by dividing the printing plate in the plate cylinder rotation axis direction with respect to each of the ink discharge ports, and the control means The control is performed for each of them.

According to the ink supply apparatus of the first aspect of the present invention, the ink preliminary supply amount to be supplied to the ink fountain before the start of printing is controlled by the control means according to the pattern area ratio of the printing plate. Accordingly, there is provided an ink supply device that does not unnecessarily retain a large amount of ink in the ink fountain of a printing press.
Further, according to the ink supply device according to claim 2 of the present invention, in the ink supply device according to claim 1, the position of the ink surface in the ink fountain is detected by the liquid level sensor, and a position signal is output. The control means that has input the position signal when the amount of ink to be discharged is zero calculates the ink consumption speed according to the pattern area ratio of the printing plate and the printing speed from the change speed of the position of the ink surface. The control is performed based on the consumption speed. That is, the preliminary ink supply amount to be supplied to the ink fountain before the start of printing is controlled based on the actually measured ink consumption speed. Therefore, it is possible to control the preliminary ink supply amount supplied to the ink fountain before the start of printing with high accuracy.
According to an ink supply device of a third aspect of the present invention, in the ink supply device according to the second aspect, the ink consumption speed data according to the pattern area ratio and the printing speed of the printing plate by the control means. Are collected, and an ink consumption speed corresponding to an arbitrary pattern area ratio and an arbitrary printing speed is calculated by linear regression calculation, and is applied to control of the ink preliminary supply amount. Therefore, in a print item such as a new print item, the preliminary ink supply amount to be supplied to the ink fountain before the start of printing can be controlled according to the pattern area ratio of the printing plate and the printing speed.
Moreover, according to the ink supply apparatus which concerns on Claim 4 of this invention, in the ink supply apparatus in any one of Claims 1-3, the said ink discharge port has a plate cylinder rotating shaft direction in plural in an ink fountain. The pattern area ratio is a pattern area ratio in each area obtained by dividing the printing plate in the plate cylinder rotation axis direction with respect to each of the ink discharge ports, and the control means controls the pattern area ratio. The control is performed for each of the areas. Therefore, an unnecessarily large amount of ink is not retained in any region in the width direction of the ink fountain of the printing press.

Next, embodiments of the present invention will be described with reference to the drawings. An example of the configuration of the ink supply apparatus of the present invention is shown in FIG. In FIG. 1, 1a and 1b are liquid level sensors, 2a and 2b are ink discharge ports, 3a and 3b are solenoid valves, 4a and 4b are ink pipes, 5 is a linear movement mechanism, 10 is a data processing unit, and 100 is an ink fountain. , 101a, 101b,... Are ink keys, and 102 is an ink discharge roller.
As shown in FIG. 1, the ink fountain 100 has a plurality of ink keys 101a, 101b,... And an ink discharge roller 102, which serve as the bottom and outer wall of the ink fountain and store ink. The ink discharge roller 102 rotates, and by rotating, a specific portion of the peripheral surface repeats whether it is inside (inner surface) or outside (outer surface) of the ink fountain 100. That is, as the ink discharge roller 102 rotates, the ink stored in the ink fountain 100 is taken out of the ink fountain 100 through the gap between the ink keys 101a, 101b,. The thickness (film thickness) of the ink film taken out of the ink fountain 100, that is, the ink film formed on the peripheral surface of the ink discharge roller 102, is determined by the gap. The gap (ink key opening) can be adjusted by operating the adjusting screws of the ink keys 101a, 101b,. The ink key opening is normally adjusted based on the pattern area ratio of the printing plate.

  The liquid level sensors 1a and 1b are sensors that detect a liquid level (ink level) of ink stored in the ink fountain 100 and output a position signal indicating the position of the liquid level. The liquid level sensors 1a and 1b are provided adjacent to the ink ejection ports 2a and 2b in the example shown in FIG. By providing the inks adjacent to each other, the displacement of the ink surface when ink is ejected from the ink ejection ports 2a and 2b can be detected at a high response speed. The liquid level sensors 1a and 1b include an ultrasonic displacement meter that measures the distance from the time until the ultrasonic pulse transmitted toward the ink surface is reflected and returned, and the position (angle) of the laser beam spot formed on the ink surface. ) And a known non-contact displacement meter such as a laser beam displacement meter that measures the distance based on the principle of triangulation can be used.

The ink discharge ports 2 a and 2 b are discharge ports that discharge ink to the ink fountain 100. Ink ejection from the ink ejection ports 2a and 2b is operated by electromagnetic valves 3a and 3b. In other words, the electromagnetic valves 3a and 3b are in an “open” state in which ink is discharged from the ink discharge ports 2a and 2b and a “closed” state in which ink is not discharged. Which state is reached is determined by an operation signal output by the data processing unit 10 and input by the electromagnetic valves 3a and 3b.
The ink pipes 4a and 4b are pipes for supplying ink to the ink discharge ports 2a and 2b. The original ink is stored in an ink can (eg drum can) or ink tank. The stored ink is fed to the pipe by a device (pump, pressure device, etc.) for feeding ink. That is, the ink in the ink pipes 4a and 4b is pressurized ink. Accordingly, ink is ejected from the ink ejection ports 2a and 2b when the electromagnetic valves 3a and 3b are in the “open” state. At this time, if the pressure of the pressurized ink and the flow characteristics of the ink are constant, the ink amount per unit time discharged from the ink discharge ports 2a and 2b is constant. Therefore, the amount of ink can be controlled by manipulating the time for ejecting ink from the ink ejection port.

  The linear movement mechanism 5 is a mechanism that moves the liquid level sensors 1a and 1b in the direction of the rotation axis of the ink discharge roller 102 and stops them at an arbitrary position. In the example shown in FIG. 1, since the liquid level sensors 1a and 1b and the ink discharge ports 2a and 2b are integrated, the movement of both is stopped simultaneously. The linear movement mechanism 5 includes a linear guide that guides a stage that supports the liquid level sensors 1a and 1b in a predetermined movement direction, a set of a ball screw and a nut that transmits a driving force for movement to the stage, and a driving force. Can be configured by a well-known technique using a step motor, a control circuit, a sensor for detecting the position of the stage (origin position, etc.), and the like. When the data processing unit 10 outputs the command data about the start of movement and the position to move, the control circuit inputs the command data, and the control circuit controls the movement stop of the stage.

  The temperature sensor 6 is a sensor that measures the ink temperature and the outside air temperature or both. There are several known factors that cause fluctuations in the flow characteristics of ink. For example, the ink has the property of thixotropy that easily flows when stirred or kneaded and returns to its original state when left untreated. Moreover, it becomes easy to flow when the temperature of ink rises, and it becomes difficult to flow when the temperature falls. The amount of ink transferred to the printing plate changes due to changes in the flow characteristics of the ink. Therefore, in an environment where the ink temperature fluctuates, the ink temperature or the outside air temperature that causes the ink temperature is measured, and the ink supply amount is adjusted according to the measured temperature, so that proper ink supply can be performed with high accuracy. Can do. The temperature sensor 6 is a temperature sensor for this purpose, and a temperature signal indicating the measured temperature output from the temperature sensor 6 is input by the data processing unit 10.

The data processing unit 10 is a part that performs data processing, for example, data processing as control means, in the ink supply apparatus of the present invention. It is also a part that provides a user interface. As the data processing unit 10, a data processing device such as a personal computer or PLC (programmable logic contraller) can be used.
The data processing unit 10 inputs a signal related to the operation state of the printing press from a printing press (not shown). For example, there are operating states such as printing start, printing stop, and printing speed. Further, the data processing unit 10 inputs data related to the print item from a production management device (not shown) or the like. For example, data such as the pattern area ratio of the printing plate, whether the print item is a new item or a repeat item, and, in the case of a repeat item, the ink consumption speed as a result. Further, the data processing unit 10 inputs position signals output from the liquid level sensors 1a and 1b. Further, the data processing unit 10 outputs an operation signal for operating the electromagnetic valves 3a and 3b. Further, the data processing unit 10 inputs a temperature signal indicating the measured temperature output from the temperature sensor 6.

The data processing unit 10 performs data processing when controlling the preliminary ink supply amount to be supplied from the ink discharge ports 2a and 2b to the ink fountain 100 before the start of printing according to the pattern area ratio of the printing plate. The control is such that the position of the ink surface in the ink fountain 100 becomes a predetermined position according to the pattern area ratio of the printing plate.
The pattern area ratio is determined by dividing the printing plate into regions by a straight line (boundary) perpendicular to the rotation axis of the plate cylinder when the printing plate is mounted on the plate cylinder, and ink is deposited in the divided region. It is the ratio of the area. Therefore, there is a pattern area ratio for each divided region. Usually, this division is performed so that each divided region corresponds to a region where each of the ink keys 101a, 101b,. The control by the data processing unit 10 so that the predetermined position corresponding to the pattern area ratio of the printing plate may be performed may be performed for each pattern area ratio for each of the divided areas. However, since the ink stored in the ink fountain 100 also flows in the left-right direction (the direction of the rotation axis of the ink discharge roller 102), each of the ink keys 101a, 101b,. . Furthermore, the average pattern area ratio obtained by averaging the entire pattern area ratio for each region can be used as the pattern area ratio.

  In the configuration of the ink supply device shown in FIG. 1, there are two sets of the liquid level sensors 1a and 1b and the ink discharge ports 2a and 2b. For example, as the pattern area ratio of the printing plate, the ink fountain 100 By applying the average pattern area ratio of the left half and the pattern area ratio of the right half, the ink preliminary supply amount can be controlled efficiently. In order to control the preliminary ink supply amount, the data processing unit 10 receives position signals output from the liquid level sensors 1a and 1b. When the ink surface does not reach a predetermined position corresponding to the average pattern area ratio, the electromagnetic valves 3a and 3b are opened and ink supply from the ink discharge ports 2a and 2b to the ink fountain 100 is started. . Further, the data processing unit 10 continues to input the position signals output from the liquid level sensors 1a and 1b, and when it detects that the ink level has reached a predetermined position, the data valves 10 set the electromagnetic valves 3a and 3b to “closed”. The supply of ink from the discharge ports 2a and 2b to the ink fountain 100 is stopped.

  The predetermined position is a position calculated based on actually measured data of the ink consumption speed as an appropriate position corresponding to the pattern area ratio. The predetermined position is a high position in a region where the ink consumption speed is fast, and the predetermined position is a low position in a region where the ink consumption speed is slow. Therefore, if the predetermined position is expressed by the distance from the bottom of the ink fountain 100, for example, the calculation includes (predetermined position) = (coefficient) × (ink consumption speed) × (printing speed). Apply an expression. Here, as the (coefficient), a small value is adopted within a range that does not cause a problem that ink runs out based on the actual data obtained by repeated printing.

  As is clear from the above arithmetic expression, the predetermined position does not reflect the size (depth) of the ink fountain 100. Therefore, problems such as ink overflowing from the ink fountain 100 and ink running out may occur. In order to prevent this, the data processing unit 10 keeps the ink surface within a predetermined reference range regardless of the predetermined position determined as described above. For example, the data processing unit 10 performs data processing for correcting the control mode based on the position signals output from the liquid level sensors 1a and 1b in the control of the ink preliminary supply amount. FIG. 2 is an explanatory diagram of control for maintaining the ink surface in the ink fountain 100 within a predetermined reference range. In FIG. 2, a predetermined reference range is set between the ink holding lower limit position and the ink holding upper limit position. When the position signals output from the liquid level sensors 1a and 1b are input and the position signals are included in the predetermined reference range, data processing for correcting the control mode is not performed.

  In the control of the ink preliminary supply amount, when at least the print item is new, the data processing unit 10 calculates the preliminary ink supply amount according to the pattern area ratio. For this calculation, the data processing unit 10 sets the amount of ink ejected to the ink fountain 100 to zero. That is, the solenoid valves 3a and 3b are set to “closed”. At that time, the position signals output from the liquid level sensors 1a and 1b are input, and the ink consumption speed corresponding to the pattern area ratio of the printing plate and the printing speed is calculated from the changing speed of the ink surface position. Then, the data processing unit 10 outputs an operation signal for operating the preliminary ink supply amount to be discharged to the ink fountain 100 based on the ink consumption speed to the electromagnetic valves 3a and 3b (that is, controls the preliminary ink supply amount to be discharged). To do). When the print item is not a new item, that is, when it is a repeat item, the control can be performed on the basis of the ink consumption speed as the record input from the production management device or the like.

The configuration has been described above. Next, the operation of the ink supply device of the present invention will be described. The operation process in the ink supply apparatus of the present invention is shown in FIG. 3 as a flowchart. In the example shown in FIG. 3, the operation process includes a preparation process before printing (S <b> 1 to S <b> 4) and a process (S <b> 5 to S <b> 8) from the start of printing to the determination of the ink amount to be discharged and the start of ink supply. ).
First, in step S1 (measuring the ink level of the ink fountain) in FIG. 3, the data processing unit 10 inputs a position signal output from the liquid level sensors 1a and 1b. The position signal includes information on the position of the ink surface stored in the ink fountain 100.
Next, in step S2 (aligning the ink surface of the ink fountain to the reference position), the data processing unit 10 calculates the difference between the ink surface position indicated by the position signal and the reference position. The ink supply to the ink fountain 100 is stopped when the printing of the previous printing item is completed. That is, in many cases, the position of the ink surface indicated by the position signal is lower than the reference position. Therefore, the data processing unit 10 outputs an operation signal for opening the electromagnetic valves 3a and 3b so that the difference is reduced. The time from opening to closing of the solenoid valves 3a and 3b is longer when the calculated difference is large, and shorter when the calculated difference is smaller. In order to align the ink surface of the ink fountain with a reference position with high accuracy, steps S1 and S2 are repeated. When the position of the ink surface indicated by the position signal is higher than the reference position, an operation signal for opening the electromagnetic valves 3a and 3b is not output, and the process proceeds to the next step.

  Next, in step S3 (preliminary supply based on the average pattern area ratio of the plate), the data processing unit 10 performs preliminary ink supply based on the pattern area ratio of the printing plate. That is, as described above, the data processing unit 10 inputs the position signal output from the liquid level sensors 1a and 1b, and when the ink surface has not reached a predetermined position corresponding to the average pattern area ratio of these areas. Then, the electromagnetic valves 3a and 3b are opened, and the ink supply from the ink discharge ports 2a and 2b to those areas of the ink fountain 100 is started. The data processing unit 10 continues to input a position signal while supplying ink, and when detecting that the ink surface has reached a predetermined position, the electromagnetic valves 3a and 3b are closed to supply the ink. Stop.

Next, in step S4 (sensing start), the data processing unit 10 inputs a position signal indicating the position of the ink surface output from the liquid level sensors 1a and 1b.
Next, in step S5 (measuring the ink consumption rate in the inspection area), the data processing unit 10 inputs a signal relating to the operating state of the printing press. When the operation state is “printing start”, the “printing speed” output by the printing press is input. The data processing unit 10 calculates the ink consumption speed based on the input data. For example, an arithmetic expression of (ink consumption speed) = (ink surface position decreasing speed) / (printing speed) is applied to the calculation. This equation shows the ink consumption speed when the printing speed is constant. In other words, the ink consumption speed is the ink consumption per unit time (the amount of decrease in the position of the ink surface) when the printing speed is constant.
Ink is not supplied to the ink fountain 100 while this calculation is being performed.

Next, in step S6 (data management based on temperature (outside air / ink) and average area ratio), the data processing unit 10 calculates the ink level lowering amount and the printing speed collected by the liquid level sensors 1a and 1b, or calculated from them. The ink consumption speed is stored, and the stored numerical values are managed as a database using the outside air temperature, ink temperature, ink brand, and average pattern area ratio as keys.
By repeating such a process at the start of printing, data representing the ink liquid level reduction amount (ink consumption speed) per unit time with respect to the average pattern area ratio is accumulated. Therefore, a linear regression operation is performed on the accumulated data to interpolate the ink consumption speed with respect to an arbitrary average picture area ratio.
A graph with the pattern area ratio on the horizontal axis and the ink consumption rate on the vertical axis is shown in FIG. The actual measurement value obtained by the calculation in step S5 is represented by one point in FIG. By repeating the process described above when printing is started, the number of points increases. In step S6, an equation (straight line) of a linear equation is obtained from the plurality of points in the example shown in FIG. By substituting into this equation, it is possible to obtain the ink consumption rate for an arbitrary average pattern area ratio.

Next, in step S7 (supplying an amount that does not exceed the upper limit of the ink level), the data processing unit 10 inputs a position signal indicating the position of the ink level output by the liquid level sensors 1a and 1b. Then, based on the ink consumption speed obtained by the above-described interpolation complement, ink for supplying the ink consumption after the start of printing is supplied. That is, the position signals output from the liquid level sensors 1a and 1b are input, and the electromagnetic valves 3a and 3b are set to “open” until the ink level reaches a predetermined position corresponding to the average pattern area ratio of these areas. Ink is supplied to the areas of the ink fountain 100 from the outlets 2a and 2b.
In addition, the data processing unit 10 uses the ink consumption speed obtained by the above-described interpolation complementation for the calculation of the preliminary ink supply amount in the next and subsequent printing.

  Next, in step S8 (when sensing or ink is insufficient), the data processing unit 10 inputs position signals output from the liquid level sensors 1a and 1b, and puts them at predetermined positions according to the average picture area ratio of those areas. On the other hand, it is determined whether or not the position of the ink surface is too low, that is, whether or not the ink is insufficient. The state where ink is insufficient is, for example, a state where the position of the ink surface is lowered by a certain distance or more with respect to a predetermined position corresponding to the average picture area ratio of each region. Naturally, when there is even one region where the ink level is lower than the ink retention lower limit shown in FIG. 2, the position of the ink surface is lowered. When the data processing unit 10 determines that the position of the ink surface is too low, the data processing unit 10 returns to step S7 and supplies ink. Further, when the data processing unit 10 determines that the position of the ink surface has not decreased too much, the data processing unit 10 stays at step S8 and continues this determination.

It is a figure which shows an example of a structure in the ink supply apparatus of this invention. It is explanatory drawing of control which keeps the ink surface in the ink fountain 100 in a predetermined | prescribed reference range. It is a flowchart which shows the process of the operation | movement in the ink supply apparatus of this invention. It is a figure which shows the graph which made the horizontal axis | shaft the pattern area rate and made the vertical axis | shaft the ink consumption rate. It is a figure which shows the ink fountain filled with a large amount of ink so that ink may not be exhausted. It is a figure which shows the process in which a large amount of ink is filled into an ink fountain so that ink may not be exhausted and printed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a, 1b Liquid level sensor 2a, 2b Ink discharge port 3a, 3b Solenoid valve 4a, 4b Ink piping 5 Linear movement mechanism 6 Temperature sensor 10 Data processing part 100 Ink fountain 101a, 101b, ... Ink key 102 Ink discharge roller

Claims (4)

An ink supply device comprising a control means for controlling a preliminary ink supply amount to be supplied to an ink fountain before starting printing in accordance with a pattern area ratio of a printing plate. 2. The ink supply apparatus according to claim 1, further comprising a liquid level sensor that detects a position of an ink surface in the ink fountain and outputs a position signal, wherein the control means sets the amount of ink discharged to the ink fountain to zero. The position signal is input, the ink consumption speed corresponding to the pattern area ratio of the printing plate and the printing speed is calculated from the change speed of the position of the ink surface after the start of printing, and the preliminary ink is calculated based on the ink consumption speed. An ink supply device that controls a supply amount. 3. The ink supply apparatus according to claim 2, wherein the control unit collects data of the ink consumption speed according to the pattern area ratio and printing speed of the printing plate, and performs an arbitrary pattern area ratio and arbitrary printing by linear regression calculation. An ink supply device that calculates an ink consumption speed according to a speed and applies the control to the ink preliminary supply amount. 4. The ink supply device according to claim 1, wherein a plurality of the ink discharge ports are arranged in an ink fountain with a plate cylinder rotation axis direction as an alignment direction, and the pattern area ratio is determined by the ink discharge port. Ink supply, characterized in that the pattern area ratio in each region obtained by dividing the printing plate in the direction of the plate cylinder rotation axis with respect to each of the ink supply means, apparatus.

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