JP4767457B2 - Control method and control apparatus for preventing occurrence of registration error during acceleration / deceleration in gravure printing press - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control method and a control device for a gravure printing machine, and more particularly to a control method and a control device for preventing occurrence of a registration error during acceleration / deceleration.
[0002]
[Prior art]
With reference to FIG. 10, a gravure printing machine for three-color printing will be briefly described. In FIG. 10, the gravure printing machine includes three-stage printing units 110, 120, and 130. The printing unit 110 includes a plate cylinder 111 and an impression cylinder 112, and a number of free rolls 113. Similarly, the printing units 120 and 130 include plate cylinders 121 and 131 and impression cylinders 122 and 132, respectively, and a large number of free rolls 123 and 133.
[0003]
The printing substrate 100 delivered from a printing substrate delivery unit (not shown) enters the first color printing unit 110 through the free roll 113 on the entry side, and the first color image is printed thereon. The printing substrate 100 on which the first color pattern is printed enters the second color printing unit 120 via a free roll, and the second color pattern is printed thereon. Similarly, the third color printing unit 130 prints the third color pattern on the printing base material 100 on which the second color pattern is printed. Thereafter, the printing substrate 100 is wound up by a winding unit (not shown).
[0004]
As is well known, in a gravure printing machine, in order to correct printing misalignment, each color printing unit prints a pattern of each color, and at the same time, register marks for detecting misprinting are spaced at equal intervals in the margin of the pattern. Print with. Registration mark detectors 124 and 134 for detecting printed registration marks are provided on the exit sides of the printing units 120 and 130 for the second and subsequent colors, respectively. The outputs of the registration mark detectors 124 and 134 are sent to the registration error correction devices 125 and 135. Each of the registration error correction devices 125 and 135 determines the amount of registration mark deviation.
[0005]
By the way, this type of gravure printing machine has a so-called line shaft type in which the plate cylinders of a plurality of stages of printing units are commonly driven by a single line shaft driven by a motor, and the printing cylinder of a plurality of stages of printing units. It is roughly classified into a so-called sectional drive type that is individually driven by a motor provided for each.
[0006]
The correction of misregistration varies depending on the above two types, but in FIG. 10, correction rolls 126 and 136 are provided on the second color and third color entrance sides, respectively, and the misregistration correction devices 125 and 135 respectively discriminate. The case where the correction rolls 126 and 136 are adjusted in the vertical direction according to the amount of deviation and the path length on the entry side of the printing unit is changed is shown. This is often used in a line shaft type gravure printing machine.
[0007]
On the other hand, in the case of the sectional drive type, the misregistration correction is performed by controlling the rotational speed of the plate cylinder in accordance with the discriminated deviation amount using the fact that the plate cylinder is driven individually. Yes.
[0008]
[Problems to be solved by the invention]
By the way, in the gravure printing machine, the tension of the printing base material entering the plate cylinder directly affects the printing registration. However, as is clear from FIG. 10, the gravure printing machine has a large number of free rolls between the plate cylinders as drive rolls, and accelerates or decelerates the printing speed (conveying speed of the printing substrate) (hereinafter referred to as acceleration / deceleration). In general, the tension of the printing substrate entering the plate cylinder is changed by the moment of inertia of the free roll. This tension variation causes the printing base material to expand and contract, causing registration errors.
[0009]
On the other hand, with conventional gravure printing machine control, even when the printing speed is accelerated or decelerated, the presence or absence of misregistration is determined by the register mark. The misregistration is corrected by the operation. In other words, there is a problem that the registration correction is performed after the registration error occurs, and the printing base material cannot be used during the correction after the registration error occurs, resulting in a waste.
[0010]
SUMMARY OF THE INVENTION An object of the present invention is to provide a control method and a control device for a gravure printing machine that can prevent the occurrence of a registration error accompanying the acceleration / deceleration of the printing speed.
[0011]
[Means for Solving the Problems]
The present invention relates to a control method of a gravure printing machine in which one or more free rolls are arranged between a plurality of plate cylinders, and printing that enters the plate cylinder in each plate cylinder during acceleration / deceleration of a printing substrate. A first multiplication value of the printing speed of the substrate and its acceleration is calculated, and further, the first multiplication value is multiplied by the elongation rate of the printing substrate, and depending on the arrangement of the free roll and the inertia moment of the free roll By multiplying a constant specific to the conveyance line, a second multiplication value is calculated, and a path length on the entrance side of the plate cylinder is adjusted by the second multiplication value, so that the plate cylinder is adjusted during acceleration / deceleration of the printing substrate. It is characterized in that the occurrence of a registration error is prevented by suppressing the fluctuation in tension of the printing substrate to be entered.
[0012]
In this control method, when the gravure printing machine is a sectional drive type, the angle of the plate cylinder is corrected by a value obtained by dividing the second multiplication value by the plate circumference of the plate cylinder.
[0013]
In this control method, at the end of the acceleration / deceleration, the adjustment amount of the path length or the correction angle of the plate cylinder is set to 0 based on a time constant obtained by dividing the path length on the free roll entering side by the printing speed. It is preferable to return it.
[0014]
Furthermore, in this control method, each plate cylinder operates its relative angle to perform correction during acceleration / deceleration, and in order to prevent a correction operation at one step from interfering with a correction operation at the next step, It is preferable that the correction operation is performed in a coordinated manner for all colors by adding the angle to the next plate cylinder in a cascade.
[0015]
According to the present invention, in the control device for a gravure printing machine in which one or more free rolls are arranged between a plurality of plate cylinders as drive rolls, the printing base material that enters the plate cylinder in each plate cylinder An acceleration detecting means for calculating the acceleration from the printing speed, a first multiplying means for multiplying the printing speed and the calculated acceleration, and an elongation rate of the printing base material on the multiplication result of the first multiplying means. And a second multiplication means for multiplying the arrangement of the free roll and a constant specific to the transport line due to the inertial moment of the free roll, and the result of multiplication of the second multiplication means A control device for a gravure printing machine characterized by adjusting a path length to reduce a registration error by suppressing a variation in tension of a printing substrate entering the plate cylinder when accelerating or decelerating the printing substrate. Will be provided
[0016]
In the present control device, when the gravure printing machine is of a sectional drive type, it further comprises a dividing means for dividing the pass length adjustment amount by the plate circumference of the plate cylinder, thereby dividing the dividing means. As a result, the angle of the plate cylinder is corrected.
[0017]
In the present control device, a time constant calculating means for calculating a time constant by dividing the path length on the free roll entering side by the printing speed, and the path based on the calculated time constant at the end of the acceleration / deceleration. First-order lag filter means for returning the length adjustment amount or the correction angle of the plate cylinder to 0 is provided.
[0018]
Furthermore, in this control device, each plate cylinder operates its relative angle to perform correction at the time of acceleration / deceleration, and in order to prevent a correction operation at one step from interfering with a correction operation at the next step, It is preferable that the correction operation is performed in cooperation with all the colors by providing a means for adding the angle in a cascade manner to the next plate cylinder.
[0019]
[Action]
In the present invention, by operating the path length on the entrance side of the plate cylinder at the time of acceleration / deceleration of the printing speed, the tension of the printing substrate entering the plate cylinder is made constant and the occurrence of registration error is suppressed. In addition, if the plate cylinder is a sectional drive, the relative phase of each plate cylinder can be made arbitrarily variable, so the relative path is manipulated during acceleration / deceleration, resulting in a path length on the entry side. The same effect as the operation can be obtained.
[0020]
The correction amount of the path length on the entrance side is obtained by multiplying the printing speed of the printing substrate by the acceleration, and multiplying this by the constant of the line configuration depending on the moment of inertia of the free roll and the arrangement, and the elongation of the printing substrate. Obtainable.
[0021]
Also, at the end of acceleration / deceleration, give the correction amount a time constant specific to the line configuration consisting of the path length and the printing speed of the printing substrate, and gradually reduce the correction amount from the end of acceleration / deceleration to the steady state phase. return.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIGS. 1-9, embodiment of the control method by this invention is described. First, a basic model of a gravure printing machine will be described with reference to FIG. Here, it is composed of a three-stage printing unit, and each stage is provided with a plate cylinder as a driving roll and an impression cylinder.
[0023]
In FIG. 6, the moment of inertia of the free roll between adjacent plate cylinders is represented by J1 and J2 between 1 color and 2 colors and between 2 colors and 3 colors, respectively. Here, when each plate cylinder accelerates simultaneously, the inertia of the plate cylinders J1 and J2 decreases the tension of the printing base of the plate cylinder side path lengths L11 and L21 (increases during deceleration), conversely. The tension of the printing base material having the path lengths L12 and L22 on the cylinder side increases (decreases during deceleration). A registration error occurs due to the tension fluctuation of the printing base on the side of the plate cylinder. In FIG. 6, v represents a printing speed (that is, a printing substrate conveyance speed), α represents an acceleration, and T represents a tension.
[0024]
Next, in FIG. 7, the tension of the printing substrate between the plate cylinders in the constant speed state is T0. By accelerating / decelerating the printing substrate, a tension difference Td is generated before and after the free roll, and the free roll is accelerated / decelerated by this tension difference Td.
[0025]
In order to suppress the tension fluctuation on the free roll exit side during acceleration / deceleration, as shown in FIG. 8, the adjustment amount (correction amount) Lm is added to the path length L2 of the free roll and the next plate cylinder. The tension between the roll and the next plate cylinder may be maintained at T0 in a constant speed state, and as a result, the occurrence of registration errors can be suppressed.
[0026]
That is, in the case of a gravure printing machine provided with a correction roll as described in FIG. 10, the correction roll may be controlled to correct the path length Lm.
[0027]
On the other hand, in the sectional drive type gravure printing machine, as shown in FIG. 9, the adjustment of the path length between the free roll and the next plate cylinder during acceleration / deceleration is performed by adjusting the relative phase of the next plate cylinder, that is, the plate cylinder. This can be realized by moving the surrounding position by Lm.
[0028]
The adjustment amount Lm of the path length between the free roll being accelerated and decelerated and the next-stage plate cylinder is set such that the acceleration α, the printing speed v, and the elongation rate Ke of the printing base material when the tension on the free roll exit side is constant at T0. Is proportional to the moment of inertia J of the free roll and inversely proportional to the path length L2 between the free roll and the plate cylinder.
[0029]
In the sectional drive type plate cylinder, the phase of the plate cylinder is corrected. Therefore, the correction angle θ is an adjustment amount inversely proportional to the plate circumference.
[0030]
The path lengths L1 and L2 shown so far are modeled with the free roll between adjacent plate cylinders as a single moment of inertia J, but in reality, there are multiple free rolls and printing is performed during acceleration / deceleration. It acts on the substrate. Therefore, among the above variables, the path length L and the inertia moment J of the free roll are set as constants specific to the transport line, and a multiplier Kt is set according to the actual machine.
[0031]
FIG. 1 shows a control system for realizing the above correction. That is, in the case of a gravure printing machine provided with a correction roll as described in FIG. 10, the printing speed v is obtained by differentiating the printing speed v with the differentiator (acceleration detecting means) 10. The acceleration α is multiplied by the first multiplier (first multiplication means) 11, and the multiplication result is multiplied by the elongation percentage Ke of the printing substrate by the second multiplier 12, and the multiplier Kt specific to the conveyance line is multiplied. The correction roll is controlled with the value multiplied by the third multiplier 13 to realize the path length adjustment amount Lm. Needless to say, the arrangement relationship between the second multiplier 12 and the third multiplier 13 may be opposite to that shown in FIG. 1, and these may be combined into one as the second multiplication means.
[0032]
On the other hand, in the case of a sectional drive type gravure printing machine, a divider 14 surrounded by a broken line in FIG. 1 is added, and the plate length is divided by the plate circumference length of the plate cylinder. The barrel drive motor is controlled to achieve the correction angle θ.
[0033]
In order to configure the control system as described above, in any type of gravure printing machine, a speed for detecting the speed of a rotating portion such as a drive motor or a plate cylinder or the printing substrate itself as the printing speed v A sensor is provided. Of course, the register mark detector signal is not used in the present invention.
[0034]
Next, referring to FIG. 2, at the end of the acceleration / deceleration of the printing speed, the tension on the free roll entering side must be returned from (T0-Td) to T0, but the tension T of the printing substrate is the path length L1. Is a first-order lag characteristic of a time constant obtained by dividing by the printing speed v of the printing substrate. Therefore, at the end of acceleration / deceleration, it is necessary to return the path length adjustment amount Lm or the plate cylinder correction angle θ to 0 in accordance with the first-order lag characteristic.
[0035]
FIG. 3 shows, in time series, the relationship between the printing speed v during and after the acceleration, the tension T of the printing substrate in the path length L1, the path length adjustment amount Lm, and the plate cylinder correction angle θ. .
[0036]
FIG. 4 shows a control system for realizing the operation after the end of acceleration / deceleration matched with the temporary delay characteristic as described above with a configuration including the first-order delay filter 20. This control system is connected to the output side of the control system shown in FIG. Needless to say, in the case of a gravure printer of the type that corrects the path length adjustment amount Lm by the correction roll, the divider 14 in FIG. 4 is deleted.
[0037]
In FIG. 4, since the path length L1 on the free roll entering side is also modeled, the proportional term that determines the first-order lag time constant is set according to the actual machine. The path length L1 is divided by the printing speed v of the printing substrate by the divider 21 to obtain a time constant T2 at the end of acceleration / deceleration. During acceleration / deceleration, the time constant is set to 0, and the path length adjustment amount Lm (or correction angle θ) is directly added to the path length (or plate cylinder angle). At the end of acceleration / deceleration, the time constant is switched from 0 to T2 and the primary delay The correction amount is set to 0 by the first-order delay curve as shown in FIG. 3 by the filter 20, and the original phase is returned to the normal state.
[0038]
The above switching is performed by providing a line for giving the time constant 0 to the first-order lag filter 20 and a line for giving the time constant T2, and providing switches S1 and S2 on the time constant 0 line and the time constant T2 line, respectively. It is realized with. Since acceleration / deceleration start and end are defined by command signals from the main controller of the gravure printing machine, normally, switch S1 is turned on and switch S2 is turned off. S2 is turned on.
[0039]
By the way, in the section drive type gravure printing machine, when the relative phase angle is operated in each plate cylinder, the correction on the exit side of the plate cylinder is opposite to that on the entrance side and directly interferes with the tension of the printing substrate in the next stage. Resulting in.
[0040]
Therefore, in this embodiment, as shown in FIG. 5, the acceleration / deceleration compensation amount at the previous stage is added to the compensation amount at the next stage, and the addition result is added to the compensation amount at the next stage, and so on. The amount is added.
[0041]
【The invention's effect】
As described above, in the present invention, when accelerating or decelerating the printing base material, the path length or the plate cylinder angle is corrected using the printing speed itself of the printing base material, not the signal of the register mark detector. Thus, it is possible to perform control before the registration error occurs, not after the registration error occurs. Therefore, as in the prior art, useless printing from when a registration error occurs until it is corrected is not performed, and wasteful disposal of the printing substrate can be reduced.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a control system for acceleration / deceleration of a printing substrate according to the present invention.
FIG. 2 is a diagram for explaining a transition in tension of a printing base on the free roll entering side at the end of acceleration / deceleration.
FIG. 3 shows, in time series, the relationship between the printing speed during and after the acceleration, the tension of the printing base material in the path length portion on the free roll side, the path length adjustment amount, and the plate cylinder correction angle. It is a figure.
FIG. 4 is a block diagram showing a control system for operation after completion of acceleration / deceleration according to the present invention.
FIG. 5 is a diagram for explaining cascade addition control of correction amounts of a plurality of plate cylinders, which is applied to a sectional drive type gravure printing machine in the present invention.
FIG. 6 is a diagram for explaining a basic model of a gravure printing machine.
7 is a diagram for explaining tension fluctuation of the printing base material when the printing base material is accelerated / decelerated in the configuration of FIG. 6; FIG.
8 is a diagram for explaining an operation necessary for suppressing a variation in tension from the state of FIG.
FIG. 9 is a diagram for explaining a case where the same tension fluctuation suppression as in FIG. 8 is realized in a sectional drive type gravure printing machine.
FIG. 10 is a diagram showing a general configuration of a gravure printing machine.
[Explanation of symbols]
10 Differentiators 11-13 First to third multipliers 14, 21 Divider 20 First order lag filters 110, 120, 130 Printing units 111, 121, 131 Plate cylinders 112, 122, 132 Impression cylinders 113, 123, 133 Free Rolls 124, 134 Registration mark detectors 125, 135 Registration deviation correction devices 126, 136 Correction rolls

Claims (8)

In a control method of a gravure printing machine in which one or more free rolls are arranged between a plurality of plate cylinders,
When accelerating and decelerating the printing substrate, each plate cylinder calculates a first multiplication value of the printing speed and acceleration of the printing substrate entering the plate cylinder, and further, the first multiplication value is calculated by the printing substrate. Multiplying the elongation rate and multiplying by a constant specific to the conveying line due to the arrangement of the free roll and the moment of inertia of the free roll, the second multiplication value is calculated, and the entrance side of the plate cylinder is calculated by the second multiplication value Control of gravure printing machine, which prevents the occurrence of registration error by controlling the tension fluctuation of the printing substrate entering the plate cylinder when the printing substrate is accelerated or decelerated by adjusting the path length of the printing substrate Method. 2. The control method according to claim 1, wherein when the gravure printing machine is a sectional drive type, the angle of the plate cylinder is corrected by a value obtained by dividing the second multiplication value by the plate circumference of the plate cylinder. A control method for a gravure printing machine. 3. The control method according to claim 1, wherein when the acceleration / deceleration is completed, the pass length adjustment amount or the plate cylinder correction is based on a time constant obtained by dividing the pass length on the free roll side by the printing speed. A control method for a gravure printing machine, wherein the angle is returned to zero. In the control method according to claim 2 or 3, in order to prevent each plate cylinder from operating at its relative angle and correcting at the time of acceleration / deceleration, and preventing a correction operation at one stage from interfering with a correction operation at the next stage, A control method for a gravure printing machine, wherein a correction angle of a certain stage is added in a cascade manner to a plate cylinder of the next stage, whereby all colors perform a correction operation in cooperation. In a control device for a gravure printing machine in which one or more free rolls are arranged between a plurality of plate cylinders,
Acceleration detecting means for calculating the acceleration from the printing speed of the printing base material entering the plate cylinder in each plate cylinder, first multiplication means for multiplying the printing speed and the calculated acceleration, and the first multiplication A second multiplication means for multiplying the multiplication result of the means by the elongation percentage of the printing substrate, and multiplying the free roll arrangement by a constant specific to the conveying line due to the moment of inertia of the free roll, and the second multiplication By adjusting the path length on the entrance side of the printing cylinder by the multiplication result of the means, when the printing substrate is accelerated or decelerated, the tension fluctuation of the printing substrate entering the printing cylinder is suppressed and the occurrence of a registration error is prevented. A control device for a gravure printing machine, characterized in that it is configured as described above. 6. The control device according to claim 5, wherein when the gravure printing machine is of a sectional drive type, further comprising division means for dividing the pass length adjustment amount by the plate circumference of the plate cylinder. An apparatus for controlling a gravure printing machine, wherein angle correction of the plate cylinder is performed based on a division result. 7. The control device according to claim 5, further comprising time constant calculating means for calculating a time constant by dividing a path length on the free roll entering side by the printing speed, and a time constant calculated at the end of the acceleration / deceleration. And a first-order lag filter means for returning the adjustment amount of the path length or the correction angle of the plate cylinder to 0 based on the control unit of the gravure printing machine. In the control device according to claim 6 or 7, in order to prevent each plate cylinder from operating the relative angle and correcting at the time of acceleration / deceleration, and preventing a correction operation at a certain stage from interfering with a correction operation at the next stage, An apparatus for controlling a gravure printing machine, comprising means for adding a correction angle of a certain stage in a cascade manner to a plate cylinder of a next stage, whereby all colors perform a correction operation in cooperation.

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