JP2001158081A - Controlling method for operation of ink pump in printing press - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a controlling method for operation of an ink pump in a printing press, in which such the frequency is reduced that ink of the ink pump is stuck and even if ink is stuck, restoration of slight sticking is made quick and further discovery of sticking of ink is made quick and loss is decreased. SOLUTION: In the controlling method for operation of the ink pump in a printing press, such an ink feeding device is equipped that both an ordinary ink feeding operation mode, in which ink is fed from an ink feeding source to an ink roller side by using the ink sucking/discharging mechanisms 21, 22, 23a in the inside of the ink pump, and an ink sticking preventing operation mode, in which ink of the inside of the ink pump 15 is rocked, are selectively changed over. When the ink pump is not moved, the ink sucking/discharging mechanisms are operated by the ink sticking preventing operation mode and thereby the ink pump is prevented from being not operated by sticking of ink.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the operation of an ink pump in a printing press which prevents the ink pump used in the printing press from sticking to the ink.

[0002]

2. Description of the Related Art Conventionally, a method of operating an ink pump for supplying an ink used for a printing machine or the like will be described with reference to a sectional view of a printing unit shown in FIG. 9, a side view of a printing unit shown in FIG. It will be described using FIG. As shown in FIG. 11, the newspaper rotary press 1 has a multi-page configuration, and performs printing such that the multi-color pages can be arranged on an arbitrary page. It comprises a front four-color back one-color unit 4, a front four-color back two-color unit 5, and the like, and a paper feed device 27 is provided so that the web 8 can be supplied to each.

The web 8 printed by the printing units 2, 3, 4, 5 is conveyed and formed into pages by the web conveying section 6, introduced into the folding machine 7, folded by the folding machine 7, and cut. The paper is discharged and transported to a counting and packing section (not shown). Explaining using the example of the front and back one-color unit 2,
As shown in FIGS. 9 and 10, the ink supplied from the ink pump unit 9 passes through the ink roller group 10 and passes through the plate cylinder 1.
The ink supplied to the printing plate mounted on 1 and attached to the pattern of the printing plate transfers to the surface of the blanket cylinder 12 and is transferred to the web 8 for printing.

Generally, the web 8 has a width of four newspaper pages as shown in FIG. 10, and the ink pump unit 9 generally has one page width and one unit. The ink pump unit 9 includes eight ink pumps 15, and the pumps 15 are individually driven by stepping motors (not shown). In newspaper printing, an operation using a part of several color units or an operation using a half of the width of the web 8 is common. Therefore, the operation of the ink pump unit 9 attached to a color unit that is not used (for example, a mark marked with a circle in FIG. 11) is stopped.

[0005]

However, if the operation is stopped for a long time, the ink may solidify due to a change in the properties of the ink and the ink pump 15 may not operate. Conventionally, when the ink pump 15 does not work, it is often noticed only after printing and knowing that ink has not adhered. Therefore, the user responds by cleaning the ink pump 15 after noticing or changing the configuration of the printing unit used. At this time, the printed matter printed becomes a waste sheet, and in some cases, the printing is started after the ink pump 15 is completely cleaned. Therefore, printing is delayed, causing trouble for the user, and handling by a large number of workers for emergency processing. Work, etc., resulting in considerable losses.

Accordingly, the present invention has been made to solve the above-mentioned problems, and the frequency of ink fixation of an ink pump is reduced. It is an object of the present invention to provide an ink pump operation control method for a printing press that can reduce the loss by speeding up the detection of the sticking.

[0007]

SUMMARY OF THE INVENTION The present invention provides first, second, and third aspects.
The third invention also relates to an ink pump operation control method for a printing press, in which an ink pump that is not used for printing is operated in an ink sticking prevention operation mode to prevent the ink pump from being disabled due to ink sticking. It is characterized by the following.

The first invention uses a normal ink supply operation mode in which ink is supplied from an ink supply source to an ink roller by using an ink suction / discharge mechanism in an ink pump.
In an ink pump operation control method for a printing press provided with an ink supply device capable of selectively switching between an ink sticking prevention operation mode in which ink in an ink pump is oscillated, when the ink pump is not operating, The ink suction / ejection mechanism is operated in the ink sticking prevention operation mode to prevent the ink pump from being unable to operate due to the ink sticking.

According to the first aspect of the present invention, the ink pump having the ink suction / discharge mechanism itself has a normal ink supply operation mode for supplying ink from the ink supply source to the ink roller side, and oscillates the ink in the ink pump. The ink sticking prevention operation mode can be selectively switched, and when the ink pump is not operating, the ink suction / removal mode is set.
Since the discharge mechanism is operated to prevent ink sticking, ink sticking is detected before printing, so that it is quickly found, the frequency of ink sticking of the ink pump is low, and it is possible to prevent the ink pump from being unable to operate due to the ink sticking.

Further, the present invention provides a normal ink supply operation mode in which ink is supplied from an ink supply source to an ink roller side by using an ink suction / discharge mechanism in an ink pump, and an ink supply operation mode in which ink in the ink pump is supplied. A plurality of ink supply devices capable of selectively switching between an oscillating ink sticking prevention operation mode, and only the ink pump of the first ink supply device used for printing in the ink supply device is used for the normal ink supply. In the ink pump operation control method for a printing press operated in an operation mode, an ink pump of a second ink supply device that is not used for printing among the plurality of ink supply devices is operated in the ink sticking prevention operation mode. The operation of the ink pump is prevented from being disabled due to the sticking of the ink pump.

According to the second aspect of the present invention, the ink pump itself having the ink suction / discharge mechanism has a normal ink supply operation mode for supplying ink from the ink supply source to the ink roller side, and oscillates the ink in the ink pump. The point that the mode can be selectively switched to the ink sticking prevention operation mode is the same as that of the first invention. However, since the ink pump of the first ink supply device for printing performs a normal ink supply operation, the ink flows. However, since the ink pump of the second ink supply device, which is not used for printing, does not perform a normal ink supply operation, an ink sticking prevention operation is performed to oscillate the ink inside the ink pump, thereby causing the ink to stick. Prevents ink pump operation failure.

The ink suction / discharge mechanism includes a pressure variable means for changing a pressure in the ink pump, and an ink suctioned from the ink suction end by the pressure variable means from the ink pump to the ink suction. Swinging means swinging toward the end or toward the ink discharge end,
A configuration in which the ink sucked in the ink pump is swung is also an effective means of the second invention.

According to this technical means, the ink suction / discharge mechanism comprises the pressure variable means and the oscillating means, and the ink sucked into the ink pump by the pressure variable means is moved into the ink pump by the oscillating means. Swinging toward the ink suction end or toward the ink discharge end, it is possible to prevent the ink from sticking.

The oscillating means has a stepping motor for driving the ink pump, and the oscillating operation is performed between the start of ink suction and the end of suction or between the start of ink discharge and the end of discharge. It is preferable that the stepping motor is configured to perform the reciprocating rotation by a predetermined angle corresponding to the section. According to such a technical means, the ink does not span the suction step from the start of ink suction to the end of the ink supply and the discharge step from the start of the ink discharge to the end of the ink discharge. It is not sent to the side.

According to the third aspect of the present invention, the first ink suction / discharge operation and the second ink suction / discharge operation performed at a cycle earlier than the first ink suction / discharge operation can be selectively varied. A plurality of ink supply devices provided with possible ink pumps, wherein only the ink pump of the first ink supply device used for printing in the ink supply device is selectively used in the first ink suction / ejection operation. In the ink pump operation control method for a printing machine that supplies ink, an ink pump of a second ink supply device that is not used for printing in the plurality of ink supply devices is driven by the second ink suction / ejection operation. The ink pump is operated in an ink sticking prevention operation mode to prevent the ink pump from operating due to the sticking of the ink.

According to a third aspect of the present invention, there is provided an ink for selectively changing a first ink suction / discharge operation and a second ink suction / discharge operation performed at a cycle earlier than the first ink suction / discharge operation. A second ink supply unit for supplying ink during normal printing by operating only the ink pump of the first ink supply device having a pump for printing in the first ink suction / discharge operation, and not providing printing for printing; The ink pump of the ink supply device is operated at a cycle earlier in the second ink suction / discharge operation than in the first ink suction / discharge operation. That is, the stepping motor for driving the ink pump is rotated in one direction at a cycle earlier than the first ink suction / discharge operation, while allowing a very small amount of ink to be discharged, or a very small amount of ink is discharged. The stepping motor for driving the ink pump is repeatedly driven in one direction and in the opposite direction at a cycle earlier than the first ink suction / discharge operation while allowing the amount.

According to this technique, for example, as shown in FIG. 6B, the anti-sticking operation is set to a cycle allowing a very small discharge amount in consideration of the printing operation time, so that the very small discharge amount of the ink is set. Can be performed and the ink sticking prevention movement mode can be performed, so that ink sticking can be prevented.

Further, when the operation of the ink pump is observed, a drive command signal to a stepping motor for driving the ink pump of the first ink supply device for printing among the plurality of ink supply devices is output. It is also an effective means in the first, second, or third invention that the ink pump is operated when the ink pump is not operating. By such a technical means, even if the ink pump of the first ink supply device used for printing is stopped, it is possible to prevent ink from sticking.

Further, when the operation of the ink pump is observed, a drive command signal to a stepping motor for driving the ink pump of the first ink supply device for printing among the plurality of ink supply devices is output. In the first, second or third aspect of the present invention, it is effective to control so that the output of the stepping motor is increased when the ink pump is not operating. By such a technical means, the ink pump in the ink pump having a lightly fixed state of ink can be released from the fixed state, which is effective.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be illustratively described in detail below with reference to the drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention thereto, but are merely illustrative examples. It's just

FIG. 1 is a block diagram of an ink pump operation control device in a printing press according to the present embodiment, and FIG.
FIG. 3 is a diagram for explaining an operation mode of the ink pump, and FIG.
FIG. 4 is a diagram illustrating the operation of the ink pump, FIG. 5 is a diagram illustrating the operation of the ink pump during the sticking prevention operation according to the first embodiment, and FIG. 6A is a diagram illustrating the first embodiment. FIG. 6B is a time chart of the ink pump operation during the anti-sticking operation according to the second embodiment. FIG. 6B is a time chart illustrating the ink pump operation during the anti-sticking operation according to the second embodiment.

In FIG. 1, an ink pump control device 28
Has a CPU (Central Processing Element) inside and is capable of selecting and setting the page configuration to be printed, the color configuration, the ink pump device to be used, and the like. The operation mode of the ink pump can be selectively set based on the mode signal.

A motor drive circuit 13 which operates in accordance with a command from the ink pump control device 28 is connected. The motor drive circuit 13 drives a stepping motor 16 so that the pump 15 operated by the motor 16 performs ink suction and discharge. Perform control. In addition, the power selector 19 controls the motor drive circuit 13 according to a command from the ink pump control device 28.
To control the number of rotations of the motor 16 to control the amount of ink suction and discharge by the ink pump 15.

Here, the configuration of the stepping motor 16 and the ink pump 15 will be described. As shown in FIG. 3, a crank 25 is fixed to the rotation shaft of the stepping motor 16, and the ink pump 15 is arranged at an angle α with respect to the rotation axis of the stepping motor 16. A barrel 2 formed in a cylindrical or prismatic shape in the ink pump 15
3 is provided with a cylindrical cavity 23a, and small-diameter ink paths 31 and 32 orthogonal to the cavity 23a are provided, and the ink path 31 side communicates with an ink fountain (not shown) to form an ink path 32.
The side communicates with the ink roller group 10 (FIG. 9).

The plunger shaft 21 is provided in the cavity 23a.
Is inserted so as to be rotatable and slidable, and a pin 24 is implanted at an outer end of the plunger shaft 21. The pin 24 is joined to a universal joint 26 provided on a crank 25 of the motor 16. The inside of the cavity is D perpendicular to the axis.
A valve cut portion 22 cut to have a cross section is provided.

Since the ink pump 15 is configured as described above, the plunger shaft 21 rotates as the stepping motor 16 rotates, and at the same time, the stroke S reciprocates in the axial direction of the plunger shaft 21. Plunger shaft 21
The ink sucks and discharges by reciprocating in the axial direction with the rotation.

That is, as shown in FIG. 4, the start of suction (1), the suction (2), the end of suction (3) and the direction of the valve cut portion 22 of the plunger shaft 21 become the direction of the suction port of the pump. The plunger shaft 21 moves leftward. As a result, the tip side of the plunger shaft 21 becomes a negative pressure, and ink is sucked from the suction port, that is, the ink path 31, and the ink is accumulated in the tip cavity 23a of the plunger shaft 21. Further, the plunger shaft 21 rotates, and the discharge start (4), discharge (5), discharge end (6), the direction of the valve cut portion 22 becomes the direction of the discharge port, and the plunger shaft 21 moves rightward in the figure. . As a result, the ink accumulated in the tip end cavity 23a of the plunger shaft 21 is pressed, and the pressed ink is discharged to the discharge port, that is, the ink path 32.
Extruded into This is repeated to supply ink.

Now, as shown in FIG. 3, the ink pump 15 is located at a position where the crank 25 of the motor 16 can be observed.
The sensor 18 is arranged at a position where the movable portion of the camera can be visually recognized. The sensor 18 may be any type that observes the movement of the ink pump 15 irrespective of the magnetic type or the light reflection type. Therefore, whether the pump 15 is operating or not is determined by the motion detection control circuit 14 in which the output change sent by the sensor 18 due to the rotation speed of the motor in each mode from the ink pump control device 28 is turned into an ON / OFF signal. By molding, it is determined whether or not a waveform is input at a predetermined pitch.

The sensor 18 is connected to the motion detection control device 14, and the motion detection control device 14 is connected to the ink pump control device 28 and the timer 20, and the timer 20 is connected to the ink pump control device 28. . Then, the timer 20 is in the ink supply movement mode,
After the drive signal of the motor drive circuit 13 which operates according to the command of the ink pump control device 28, the operation of the pump is determined, and when the pump is not operating, time measurement is started and the time is sent to the ink pump control device 28. . In addition, the timer 20 determines the movement of the pump after the drive signal of the motor drive circuit 13 that operates in accordance with the command of the ink pump control device 28 in the sticking prevention movement mode, and starts timing when the pump is not moving. Is sent to the ink pump controller 28.

The ink pump control device 28 is connected to a machine stopping device 29 and an alarm device 30. If the movement of the ink pump 15 cannot be detected within a specified time, the machine stopping device 29 is driven to drive the printing press. Is stopped, and an alarm indicating the ink fixation state is output to the alarm device 30.

In the case of the ink pump used for the operation, the mode signal from the ink pump operation mode switching circuit 17 is, as shown in FIG. The rotation speed N at which the stepping motor 16 is rotated is determined by the initial setting for setting the ejection amount in accordance with the image ratio of the printed pattern in the portion covered by 15 and the rotation degree B determined by the adjustment value by the minute adjustment operation by the operator. The ink is sent to and stored in the pump control device 28, and an appropriate amount of ink corresponding to the pattern and speed is ejected in the same manner as in the related art.
Note that the rotation speed N of the stepping motor 16 is N = Max
The ink pump 15 is operated at the number of rotations × A × B.

In the case of an ink pump which is not used for the operation, as shown in FIGS. 2B and 2C, an anti-adhesion operation mode for performing an anti-adhesion operation is sent to and stored in the ink pump control device 28. . That is, when the input to the stepping motor drive circuit 13 of FIG. 2B is driven by a command system of a constant rotation speed irrespective of the image ratio or speed, "A" is used.
Is selected, or when “C” in FIG. 2C is selected, the driving cycle T, the direction of rotation, the rotation angle θ, and the duration as shown in FIG. It becomes the sticking prevention operation mode in which the time t is set.

By the way, as a typical operation method of the sticking prevention operation, the direction of the valve cut portion 22 of the plunger shaft 21 is applied to both the suction port and the discharge port as shown in FIGS. 5 (a) and 5 (b). The robot is repeatedly rotated in a range where no problem occurs (a range of ± θ), and the operation is performed as shown in FIG. Alternatively, as shown in FIG. 6B, a very small amount of ink is discharged and the plunger shaft 21 is rotated in the same direction for a very short period of time at a specific cycle. You may make it rotate repeatedly for a long time.

Next, the operation of the present embodiment thus configured will be described with reference to the flowchart of FIG. In a state where the power of the printing press operation is turned on and whether or not the ink pump 15 is used for the operation is determined in advance by a selection command,
The way of operation is changed between the ink pump 15 used for operation and the ink pump 15 not used for operation. That is, in the case of the ink pump used for operation (50),
In the ink supply operation mode (51), as shown in FIG. 2 (a), the rotation degree A determined by a function based on the printing speed and the discharge amount corresponding to the image ratio of the printed pattern of the portion covered by the ink pump 15 are set. The motor 16 is rotated by the number of rotations N at which the stepping motor 16 is rotated according to the initial setting for the rotation and the rotation degree B determined by the adjustment value by the minute adjustment operation by the operator, and the ink is supplied.

This ink supply operation mode continues until the end of printing as long as the ink pump used for the operation is running (52). However, the operation of the ink pump used for the operation is stopped (52) and the operation is resumed. If the ink pump is not used (50), the operation proceeds to the sticking prevention operation mode (53).

When the operation of the ink pump used for the operation is stopped (52), the operation enters the anti-sticking operation mode (53), and it is determined whether or not the pump is operating again. If the pump is operating (54). , If it is an ink supply operation pump (55), the ink supply operation mode (5
Returning to 1), printing is continued.

If the pump is not operating in step (54), the driving force of the pump is increased (57).
If the pump does not operate even after the specified time has passed, it is determined again whether the pump is an ink supply operation pump (58).
If the ink supply pump is used, the printer is stopped and an alarm is issued (59).

On the other hand, in step (50), if the ink pump is not used for the operation, the operation proceeds to the anti-sticking operation mode (53). If the pump is not operating, the timer 20 is operated to start the time measurement ( 54), The driving force of the pump is increased (57), and if the pump does not operate after the lapse of the specified time, it is determined again whether or not the pump is an ink supply operation pump (58). , The operation of the ink pump is stopped and an alarm is issued (60).

As described in detail above, in the present embodiment, in the ink pump 15 for performing the ink supply operation, if the ink pump 15 is not fixed, the ink supply operation is continued, and the ink pump 15 is fixed. In this case, the sticking of the pump 15 is detected by the sensor 18, the sticking prevention operation is started, and the power is increased. However, if the pump 15 does not move within the specified time, the printing press is stopped and an alarm is issued. Can be fixed by this operation,
Even if it does not recover, the fixation is found before operation, so the machine can be stopped, the machine configuration can be changed, the path of the printing paper can be changed and operation can be performed, or the ink pump 15 can be disassembled and cleaned.

Accordingly, the frequency of inoperability due to sticking is reduced, and even if sticking occurs, it is known before printing, so that waste of paper due to printing can be reduced, time wasted, the printing configuration is changed, and the pump 15 is cleaned. Time can be allocated, productivity can be improved, and costs can be reduced.

Further, the ink pump 15 which does not supply the ink is set in the sticking prevention operation mode, and is operated occasionally so that the ink is not fixed without discharging the ink. Even if sticking occurs, the power selector 19 drives the stepping motor 16 with high output, so that light sticking can be eliminated, and the frequency of operation failure due to sticking can be further reduced. Can be.

The sensor 1 detects the movement of the ink pump 15.
8, the fixing state can be detected early, and the fixing frequency can be greatly reduced including the case of the above-described ink supply operation mode. Therefore, it is possible to largely reduce waste of paper, wasted time, and improve productivity. , Cost can be reduced.

In addition, as shown in FIG. 6B, a method in which the sticking prevention operation is performed with an extremely small discharge amount in an operation cycle in consideration of the printing operation time can also be performed. In this case, the simultaneous cleaning after the printing operation is sufficient. The same effect can be obtained because the discharge can be performed to any extent.

FIG. 8 is an operation flow chart of the ink pump according to the second embodiment. When the power for the printing press operation is turned on and the ink pump is used for the operation (50), the ink supply operation mode (51) is entered to supply the ink.

This ink supply operation mode continues until the end of printing as long as the ink pump used for the operation is running (52). However, when the ink pump used for the operation is stopped (52), the operation of the pump is stopped. The drive power is increased (57), and if the pump does not operate after the specified time (61), the printing press is stopped and an alarm is issued (59). If the ink pump is not used for operation (50), the operation proceeds to the sticking prevention operation mode (53).

If the pump is not running,
0 is activated to start timekeeping (54), the driving force of the pump is increased (57), and if the pump does not operate after the specified time (56), the operation of the ink pump is stopped and an alarm is issued. Is issued (60).

In this embodiment, when it is detected in the ink supply operation mode that the ink pump 15 is not operating, the machine operation may be immediately stopped and an alarm may be issued.

In the second embodiment, the operation is performed as described above. Therefore, in the above-described first embodiment, when the ink pump 15 for supplying ink detects that the ink pump 15 is not operating in the ink supply operation mode, the ink pump 15 is switched to the sticking prevention operation mode and operated. 8, the operation mode is not set to the sticking prevention operation mode as shown in FIG.
In this case, the power is increased by increasing the exciting current, and the operation is performed as it is. When the specified time is exceeded, the machine stops operating and issues an alarm.

As described in detail above, the second embodiment is
The same operations and effects as those of the first embodiment can be obtained, and the system is simplified since the flow is simplified.

[0050]

As described above in detail, according to the present invention, the frequency of ink sticking of the ink pump is reduced, and even if ink is stuck, light ink can be recovered quickly, and the discovery of ink sticking can be accelerated. Thus, it is possible to provide a method of controlling the operation of the ink pump in a printing press, which reduces the loss.

[Brief description of the drawings]

FIG. 1 is a block diagram of an ink pump operation control device in a printing press according to an embodiment.

FIG. 2 is a diagram illustrating an operation mode of an ink pump.

FIG. 3 is a configuration diagram of an ink pump.

FIG. 4 is an explanatory diagram of an operation of the ink pump.

FIG. 5 is an explanatory diagram of an ink pump operation during a sticking prevention operation according to the first embodiment.

FIG. 6A is a time chart of the ink pump operation during the sticking prevention operation according to the first embodiment, and FIG. 6B is a time chart of the ink pump operation during the sticking prevention operation according to the second embodiment. FIG.

FIG. 7 is a flowchart according to the first embodiment.

FIG. 8 is a flowchart according to a second embodiment.

FIG. 9 is a sectional view of a printing unit.

FIG. 10 is a side view of the printing unit.

FIG. 11 is an overall front view of a newspaper rotary press.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Newspaper rotary press 15 Ink pump 16 Stepping motor 21 Plunger

Claims (7)

[Claims] 1. An ordinary ink supply operation mode in which ink is supplied from an ink supply source to an ink roller side by using an ink suction / discharge mechanism in an ink pump, and ink sticking prevention in which ink in the ink pump swings. In an ink pump operation control method for a printing press provided with an ink supply device capable of selectively switching between an operation mode and an operation mode, when the ink pump is not operating, the ink suction / ejection mechanism is operated in the ink sticking prevention operation mode. A method for controlling the operation of an ink pump in a printing press, wherein the method comprises: 2. A normal ink supply operation mode in which ink is supplied from an ink supply source to an ink roller side by using an ink suction / discharge mechanism in an ink pump, and ink sticking prevention in which ink in the ink pump swings. A plurality of ink supply devices capable of selectively switching between an operation mode and a printing operation in which only the ink pump of the first ink supply device used for printing in the ink supply device is operated in the normal ink supply operation mode; In the method for controlling the operation of an ink pump in a machine, an ink pump of a second ink supply device that is not used for printing in the plurality of ink supply devices is operated in the ink sticking prevention operation mode, and the ink pump due to the sticking of the ink is operated. A method for controlling operation of an ink pump in a printing press, comprising preventing operation failure. 3. The ink suction / discharge mechanism includes: a pressure variable unit that changes a pressure in the ink pump; and an ink sucked from an ink suction end by the pressure variable unit.
3. A swing unit swinging from the inside of the ink pump toward the ink suction end or toward the ink discharge end, wherein the ink sucked in the ink pump is swung. An ink pump operation control method in the printing press according to the above. 4. The oscillating means has a stepping motor for driving the ink pump, and the oscillating operation is performed between the start of ink suction and the end of suction or between the start of ink discharge and the end of discharge. 4. The ink pump operation control method for a printing press according to claim 3, wherein the step is performed by reciprocating the stepping motor by a predetermined angle corresponding to a section. 5. A first ink suction / discharge operation and said first ink suction / discharge operation.
A plurality of ink supply devices provided with ink pumps capable of selectively changing a second ink suction / discharge operation performed at a cycle earlier than the ink suction / discharge operation of the present invention, and performing printing in the ink supply device. In an ink pump operation control method for a printing machine that selectively supplies ink by the first ink suction / discharge operation only to the ink pump of a first ink supply device, the method includes the steps of: performing printing in the plurality of ink supply devices; The ink pump of the second ink supply device, which is not provided, is driven by the second ink suction / discharge operation to operate in the ink sticking prevention operation mode to prevent the ink pump from being disabled due to the ink sticking. A method for controlling the operation of an ink pump in a printing press. 6. A drive command signal to a stepping motor for driving the ink pump of a first ink supply device for printing among a plurality of ink supply devices while observing the movement of the ink pump. 6. The ink pump operation control method for a printing press according to claim 1, wherein when the ink pump is not operating, the operation in the ink sticking prevention movement mode is performed. 7. A drive command signal to a stepping motor for driving the ink pump of the first ink supply device for printing among a plurality of ink supply devices while observing the movement of the ink pump. 6. The ink pump operation control method for a printing press according to claim 1, wherein when the ink pump is not operating, the output of the stepping motor is controlled to increase.