JPH0649370B2 - Method and device for automatic press-fitting of printing machine - Google Patents

Description

The present invention relates to a rotary plate cylinder type printing machine, and more particularly to a printing machine in which pressure setting and press-fitting of an impression cylinder that presses printing paper against a blanket cylinder in a printing mode is automated. The present invention relates to an automatic press-fitting method and device.

[Conventional technology]

2. Description of the Related Art In recent years, card printing machines have been in the limelight with the diversification of printing demand. The printed cards include business cards, postcards, telephone cards, coasters, and the like, and have various thicknesses. When printing such a comparatively large amount of card, an offset printing machine using a rotary plate cylinder method is used.

Here, the offset printing machine has a plate cylinder around which a printing plate is wound, a blanket cylinder that rotates by pressing the plate cylinder, and an impression cylinder that rotates by pressing printing paper on the blanket cylinder. . When the blanket cylinder is rotated by the main motor, the plate cylinder and the impression cylinder gear-connected to the blanket cylinder rotate at a constant circumferential speed.

Next, after supplying water to the printing plate wound around the blanket cylinder, the oily ink is uniformly supplied by the ink roller. Ink only adheres to it. And
The ink attached to the printing plate is transferred to the peripheral surface of the blanket cylinder as the plate cylinder rotates.

Next, after setting the blanket cylinder in the press fit state,
When, for example, card paper as printing paper is supplied between the blanket cylinder and the impression cylinder, the card paper passes while being pressed against the blanket cylinder by the impression cylinder. Here, since the ink applied to the printing portion of the printing plate is transferred to the peripheral surface of the blanket cylinder as described above, this ink is transferred again to the card paper, and the printing plate is printed on the card paper. Printing is performed by coloring the portion corresponding to the printed portion of with ink.

Here, a press-fitting mechanism of an offset printing press based on a rotary plate cylinder method that has been generally used in the past is a lever that is rotationally engaged with an eccentric shaft of an impression cylinder that rotatably supports the impression cylinder via a relief mechanism by a spring. Is provided, and by rotating this lever, the impression cylinder is moved to a set position in which the impression cylinder is separated from the blanket cylinder by 0.05 to 0.3 mm depending on the thickness of the paper. The adjustment of the set position is set by rotating the handle for adjusting the printing pressure. Therefore, in the press-fitting mechanism configured as described above, printing paper having a thickness equal to or greater than the set interval passes between the blanket cylinder and the impression cylinder, and the printing force is set by the relief position of the impression cylinder by the spring. The pressure will be set. In the press-fitting operation, first, the print pressure adjustment handle is operated according to the thickness of the printing paper to be used to adjust the set position, and then the test print is performed. The printing pressure is set to the optimum value by operating the handle for.

[Problems to be solved by the invention]

However, in the printing machine having the above configuration, the setting position must be adjusted according to the thickness of the printing paper, so it is necessary to accurately grasp the paper thickness of the printing paper. Also, in a printing machine that prints ordinary paper, since the range of paper thickness used is narrow, it is possible to make the printing pressure almost constant by the escape force of the impression cylinder by the spring. When handling a wide range of card paper, such as telephone cards, etc., to very thick cards, such as coasters, it is possible to cover the entire range of paper thickness simply by using the spring to relieve the impression cylinder. Since the printing pressure cannot be optimized, the printing quality is deteriorated, resulting in the need for a specialized operator.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an automatic press-fitting method and device for a printing press that can automatically perform press-fitting suitable for printing paper used by a simple operation. To do.

[Means for solving problems]

An automatic press-fitting method of a printing machine according to the present invention includes a blanket cylinder to which printing ink is transferred on a peripheral surface, and a rotatable eccentric portion of an impression cylinder eccentric shaft so that the peripheral surface can be pressed against the peripheral surface of the blanket cylinder. A supported press cylinder, wherein the press cylinder is rotated about the center of rotation of the eccentric shaft of the press cylinder to bring the printing paper into close contact with the peripheral surface of the blanket cylinder. A first member that can rotate integrally with the center of rotation of the shaft and a second member that can move at a constant speed by a press-fitting motor are provided, and one sheet of printing paper is interposed between the blanket cylinder and the impression cylinder. Then, the first member is rotated in the press-fitting direction by the second member via the elastic body to bring the printing paper into close contact with the blanket cylinder and the impression cylinder, and the movement of the second member is started. From the above by stopping the first member The time required to deform the body by a predetermined amount is stored as a reference pressure control amount, and a pressure adjustment control amount is obtained by adding a correction for fine adjustment to this reference pressure control amount, and when printing using the printing paper, The press-fitting motor that controls the rotation of the impression cylinder eccentric shaft is controlled by a value corresponding to the press-fitting control amount from the press origin.

In order to achieve such a press-fitting method, the automatic press-fitting device of the printing machine according to the present invention can press the peripheral surface of the blanket cylinder to which the printing ink is transferred and the peripheral surface of the blanket cylinder. And an impression cylinder rotatably supported on the eccentric portion of the impression cylinder eccentric shaft, and the printing cylinder is rotated by rotating the impression cylinder about the center of rotation of the impression cylinder eccentric shaft. In a printing press closely contacting with a peripheral surface, a first member fixed to a rotation center portion of the impression cylinder eccentric shaft, and a holding member rotatably supported by the impression cylinder eccentric shaft around the rotation center portion. A second member that is rotationally controlled at a constant speed by a press-fitting motor with a function, and the first member that is provided between the first and second members to rotate the first member in the press-fitting direction. Press the elastic body that accompanies the press-fitting motor A paper setting switch that is activated in the reverse direction, a pressure origin sensor that detects the initial position of the drive control system from the press-fitting motor to the impression cylinder, and a predetermined rotation angle between the first and second members. A reference pressure sensor that detects that the elastic body is deformed by a predetermined amount due to a difference and a press-fitting control unit, and the press-fitting control unit is a state in which the printing paper is inserted between the blanket cylinder and the press cylinder. The control amount of the press-fitting motor from the time when the pressure origin sensor is set to the time when the reference pressure sensor is operated is taken in as a reference pressure control amount, and a correction for fine adjustment is added to the reference pressure control amount. A press-fitting control amount is calculated, and the press-fitting control amount is given to the press-fitting motor during actual printing using the printing paper.

[Action]

In the automatic press-fitting method and apparatus of the printing press configured as described above, the printing paper (card paper) is simply inserted between the blanket cylinder and the impression cylinder, and the paper setting switch is operated. It automatically calculates the press-fitting position that suits, and automatically reproduces the press-fitting position when printing, so without knowing the thickness of the printing paper,
The printing pressure suitable for this printing paper is automatically obtained. When such a method and configuration are adopted, even if the thickness range of the card paper used is extremely wide like a card printing machine, the press-fitting position is automatically set for each card paper, The optimum print quality will always be obtained. In addition, since the printing pressure can be adjusted only by changing the correction amount even during printing, it is extremely easy to adjust the printing quality.

Example of Invention

FIG. 1 is a front view of a main part of a press-fitting mechanism part showing an embodiment of an automatic press-fitting method and device for a printing press according to the present invention. In the figure, reference numeral 1 is a blanket cylinder rotated by a main motor (not shown), and a plate cylinder (not shown) having a printing plate wound on its peripheral surface is pressed to rotate at a constant circumferential speed. Reference numeral 2 denotes an impression cylinder that can rotate about the eccentric portion of the impression cylinder eccentric shaft 3. When printing paper is supplied in the print mode, the eccentric portion is rotated about the center of rotation of the impression cylinder eccentric shaft. It is rotated counterclockwise in FIG.
The peripheral surface of the same impression cylinder 2 is pressed against the peripheral surface of the blanket cylinder 1 via the printing paper, and the printing paper is brought into close contact with the peripheral surface of the blanket cylinder 1 with a set pressure. Reference numeral 4 is a print paper supply detection sensor for detecting the print paper supplied from the print paper supply mechanism 5 between the blanket cylinder 1 and the impression cylinder 2, and 6 is an arm as a fan-shaped first member, The acute angle portion is fixed to the impression cylinder eccentric shaft 3. Reference numeral 6a is a tongue piece in which a part of the arm 6 is bent, and reference numeral 7 is an arm as a second member rotatably supported substantially coaxially with the arm 6, and has a width narrower than that of the arm 6. . 7a,
Reference numeral 7b is a tongue piece in which a part of the arm 7 is bent, and 8 is a reference pressure sensor fixed at a position farthest from the tongue piece 6a on the arm 6 in the rotational direction. Generates a pressure detection signal. Reference numeral 9 denotes a spring that serves as an elastic body that prevents the arms 6 and 7 from rotating in opposite directions, and in this case, is stretched between the tongue pieces 6a and 7a. Reference numeral 10 denotes a fan-shaped gear, which is fixed to the tip of the arm 7 so as to project more outward than the arm 6. Reference numeral 11 denotes a press-fitting motor having a holding function when stopped, and examples of the motor having such a function include a stepping motor, a servo motor, an ultrasonic motor and the like. In the following description, a stepping motor is used as the press-fitting motor. 12 is a gear mounted on the output shaft of the press-fitting motor 11, 13 is a gear having a diameter sufficiently larger than the gear 12 rotatably supported by the shaft 14, and 15 is a gear 13 coaxially fixed to the gear 13. The gear 15 has a sufficiently small diameter, and the gear 15 meshes with the gear 10. Therefore, the gears 13 and 15 sufficiently decelerate the rotation output of the press-fitting motor 11 to rotate the arm 7. Reference numeral 16 is a pressure origin sensor fixed to the frame, and when a sensor arm 16a fixed to the side surface of the gear 13 is detected, a pressure origin detection signal is generated.

In addition, the pressure origin is the state where the press-fitting motor 11 is free,
That is, when the power is turned off and the hold function is released, the tension of the spring 9 causes the tongue 6a and the tongue 7 to move.
When b is closest to the rotating direction and the impression cylinder 2 is the farthest from the blanket cylinder 1, the press-fitting motor 11
It is set at a position where the pressure origin detection sensor 16 cannot detect the pressure origin unless it is reversed. If this is done while the press-fitting motor 11 is rotating in the forward direction when searching for the pressure origin, this direction is the press-fitting direction. Therefore, if the arm 16a cannot be detected for some reason, the press-fitting state is set. This is to prevent the occurrence of an accident such as damage to the blanket cylinder when a thick card paper is inserted due to the progress of.

FIG. 2 is a block diagram showing a control system, in which 17 is a paper setting switch, 18 is an operation switch, 19 is a stop switch, 20 is a printing pressure fine adjustment switch, and 21 is a control unit, Detection sensor 4, reference pressure detection sensor 8, pressure origin detection sensor 16, paper setting switch 1
7, a central processing unit (hereinafter referred to as CPU) 22 to which the output signals of the operation switch 18, the stop switch 19 and the printing pressure fine adjustment switch 20 are input, and a read only memory (hereinafter, referred to as a CPU) 22 in which a processing program is stored. RO
23), a random access memory (hereinafter referred to as RAM) 24 for storing various data, and an oscillating circuit 25 for generating a clock signal as a reference for processing and supplying the clock signal to the CPU 22. 26 is the CPU 2
2 is a driver circuit for rotationally driving the press-fitting motor 11 according to the output signal of 2.

The operation of the automatic press-fitting device of the printing press having the above configuration will be described below with reference to the flowchart shown in FIG.

First, when the power is turned on, the CPU 22 operates and the third
As shown in step S ₁ of the figure, it is determined whether or not the pressure origin sensor 16 detects the arm 16a and generates a pressure origin detection signal. Here, when the determination result in step S ₁ is a node, since the pressure origin search is set to be performed by the reverse rotation drive as described above, the reverse rotation drive pulse of the unit number is generated. It is supplied to the driver circuit 26. When the driver circuit 26 receives the rotational drive command, the driver circuit 26 rotates the press-fitting motor 11 in the reverse direction by the command pulse number, that is, in the direction opposite to the arrow in FIG. 1, in response to the command signal. Next, returning to step S ₁ , it is determined whether or not the pressure origin is detected. Such a behavior to the determination of the step S ₁ is a yes, that continue until圧原point is detected. When圧原point detection sensor 16 generates a圧原point detection signal by detecting the sensor arm 16a, the determination in step S ₁ in the CPU22 proceeds to step S ₃ becomes YES.
Next, in step S _3, the process proceeds to step S ₄ after resetting the paper setting flag F.

Since the press-fitting motor 11 has the holding function as described above, it is in the hold state at the pressure origin detection position. When the press-fitting motor 11 is in the hold state, all the parts meshing with the output shaft of the press-fitting motor 11 are locked and the position is fixed.

Here, when operating the sheet setting switch 17 after inserting the print sheet that is intended to be printed between the blanket cylinder 1 and impression cylinder 2, the determination in step S ₄ proceeds to step S ₅ becomes YES. Step S ₅
In, the CPU 22 generates a unit number of normal rotation pulses and supplies them to the driver circuit 26. Then, the driver circuit 26 drives the press-fitting motor 11 in the normal direction by an amount designated by the number of pulses. Here, when the press-fitting motor 11 rotates normally, the gear 12 mounted on the output shaft rotates counterclockwise as indicated by the arrow in FIG. When the gear 12 rotates counterclockwise, the large diameter gear 13 meshing with the gear 12 is decelerated and rotates clockwise. When the gear 13 rotates, the small diameter gear 15 coaxially fixed to the gear 14 also rotates to the right.

Here, the small-diameter gear 15 is fixed to the tip portion of the arm 7 and has the same fan-shaped gear 1 as the large-diameter gear.
Since the gear 15 meshes with 0, the right rotation of the gear 15 causes the arm 7 to rotate to the left while the speed is further reduced. Then, the number of forward rotation pulses generated in step S _5, since a small number of pulses are determined in advance,
The movement amount of the arm 7 is very small. When the process of step S ₅ in this manner is completed, a determination of among whether the reference pressure detection sensor 8 are generating reference pressure detection signal proceeds to step S _6. Here, if the determination in step S ₆ is NO, the process returns to step S ₅ to execute the unit amount press-fitting operation, and then the determination in step S ₆ is performed. When such an operation is repeated, the arm 7 is sequentially rotated leftward, so that the arm 6 is also rotated leftward via the spring 9. Since the arm 6 is fixed to the eccentric cylinder eccentric shaft 3, rotation of the arm 6 to the left moves the impression cylinder 2 to the blanket cylinder 1 via the printing paper.
It means that they are moving closer to. And
When the impression cylinder 2 is pressed against the blanket cylinder 1 via the printing paper to prevent its movement, the arm 6 is fixed in that position, and only the arm 7 rotates left against the tension of the spring 9. Will continue. Then, when the arm 7 reaches the position of the reference pressure detection sensor 8, the reference pressure detection signal is generated assuming that the printing pressure corresponding to the extension of the spring 9 is applied to the printing paper. In this way, when the reference pressure detection signal is generated, the CPU 22 makes a positive determination in step S ₆ and proceeds to step S ₇ . In step S _7, stores the fourth from圧原point detection position A shown in FIG., The RAM24 number forward pulses generated to a position where printing pressure V predetermined is applied to the printing paper as a reference pressure control amount X To do. Then, step _{S 8}
In the above, the press-fitting control amount Y is calculated by adding the correction of the fine adjustment amount nΔx to the reference pressure control amount X to calculate RA.
Store in M24. Here, since Δx is a constant, the fine adjustment uses the content of the soft counter that is incremented and decremented each time the printing pressure fine adjustment switch 20 shown in FIG. 2 is operated up / down as the correction value n. . In this case, the correction value n for maximizing the printing pressure is 0, and by setting the correction value n to 0, as is apparent from FIG. 4, the press-fitting control amount Y becomes the reference pressure. It will coincide with the controlled variable X. By doing so, no matter how much the printing pressure is increased by fine adjustment, the printing pressure does not rise above the reference pressure, and damage to the blanket cylinder 1 and the like is prevented.

Next, in step S _9, and calculates the standby position Z in the case where the supply of the printing paper during and printing until the printing paper at the start of printing is supplied and stopped RAM2
Store in 4. Here, the standby position Z is calculated by executing Y-k. Since k is a constant, the standby position is a position that is always a certain distance away from the press-fitting position. This is because the press-fitting operation is performed quickly and accurately by setting the standby position at a position sufficiently closer to the press-fitting position than the press-origin detection position.

Next, in step S _10, and generates a reverse rotation pulse to reach the圧原point, to secure the impression cylinder located in圧原point. Next, in step S _11, the process proceeds to step S ₄ after setting the flag F indicating the completion of the paper setting process. When the setting of the paper in this manner is completed, the determination in step S ₄ from the determination in step S ₁₂ to transition when was no is yes, the process proceeds to step S _13.

Next, when the operation switch 18 is operated, the result of the determination is NO, and the operation that has been waiting due to the repeated operation is determined to be YES, and the process proceeds to step S ₁₄ . Step S
_{In 14} , the Z normal rotation pulses are generated to further move the impression cylinder located at the pressure origin in the press-fitting direction to move to the standby position Z. Next, in step S _15, the printing paper feed detecting sensor 4 Wait until HatsuTadashi the detection signal, when the supply of the printing paper is detected, the determination moves to step S ₁₆ is YES. Step S ₁₆
In, by generating k number of forward rotation pulse, performs printing by setting the impression cylinder 1 on the calculated pressed Re position in step S _8. Next, in step S _17, from the output of the printing sheet feed detection sensor 4, a determination of among whether the next printing paper is supplied. And
If this determination is yes, the printing state is continued by repeating the operation. In contrast, when the supply of the printing paper is cut off, the determination in step S ₁₇ proceeds to step S ₁₈ is NO. Step S ₁₈
In order to prevent contact of the impression cylinder 2 with the blanket cylinder 1, since the supply of printing paper is stopped,
Generates a number of reverse rotation pulses, the process proceeds to step S ₁₉ to set the impression cylinder 2 to the standby position. In step S _19, performs a determination within whether stop switch 19 is operated, if the determination result is no, waits for supply of print paper proceeds to step S _15. Further, when the determination in step S ₁₉ is yes,
Returns to the step S ₄ to determine the state of the sheet setting switch 17.

Although not shown in FIG. 3, the printing pressure adjustment switch 2
When 0 is operated up or down, the Y value and the Z value associated therewith are corrected in real time by interrupt processing, so that the printing pressure can be corrected even during printing.

Therefore, in the automatic press-fitting method and apparatus of the printing press configured as described above, the paper setting switch 17 is provided by sandwiching the printing paper to be used between the blanket cylinder 1 and the impression cylinder 2 whose rotation is stopped. Even if the thickness of the printing paper is not grasped only by operating, the optimum press-fitting position when this printing paper is used is automatically obtained. Next, when the operation switch 18 is operated, the impression cylinder 2 is quickly and accurately moved and held at the press-fitting position which is automatically obtained in advance, so that the optimum printing pressure is reproduced and high-quality printing is performed. Will be easily obtained from the beginning. And in the printing press configured in this way,
Since the printing paper itself is placed between the blanket cylinder 1 and the impression cylinder 2 to automatically set the conditions, even when the thickness of the card paper to be used varies widely, as in a card printing machine, a new Blanket cylinder 1
This can be dealt with by an extremely easy operation in a nearly completely automatic state, in which the paper setting switch is operated only by operating the paper setting switch between the pressure cylinder 2 and the pressure drum 2.

In the above embodiments, the case where the control unit is configured by software processing using the CPU has been described, but the present invention is not limited to this, and may be configured by a dedicated circuit. There is also no. Furthermore,
In the above embodiments, the case where the stepping motor is used as the press-fitting motor has been described, but any device having a holding function may be used, and a servo motor, an ultrasonic motor or a general motor may be used as those having these characteristics. A motor mechanism combined with an electromagnetic brake is possible.

〔The invention's effect〕

As described above, the automatic press-fitting method and device for the printing press according to the present invention is such that the printing paper (card paper) is inserted between the blanket cylinder and the impression cylinder and the paper setting switch is operated. Since the press-fitting position that matches the print paper is automatically calculated and this press-fitting position is automatically reproduced at the time of printing, it is possible to print a print mark that matches the print paper without knowing the thickness of the print paper. The pressure will be obtained automatically. When such a method and configuration are adopted, even if the thickness range of the card paper used is extremely wide like a card printing machine, the press-fitting position is automatically set for each card paper, The optimum print quality will always be obtained. Further, since the printing pressure can be adjusted only by changing the correction amount even during printing, there are various excellent effects such as extremely easy adjustment of printing quality.

[Brief description of drawings]

FIG. 1 is a side view of an essential part showing an embodiment of an automatic press-fitting method and apparatus for a printing press according to the present invention, FIG. 2 is a block diagram showing an example of a control system, and FIG. 3 shows the operation of FIG. FIG. 4 is a flow chart for explaining, and FIG. 4 is a characteristic diagram showing the relationship between the movement amount of the impression cylinder and the drive pulse supplied to the press-fitting motor. 1 is a blanket cylinder, 2 is an impression cylinder, 3 is an eccentric axis of the impression cylinder, 4 is a printing paper supply detection sensor, 6 and 7 are arms (first and second members), 6a and 7a are tongue pieces, and 8 is a reference Pressure detection sensor, 9 is a spring (elastic body), 10, 12, 13, 1
5 is a gear, 11 is a press-fitting motor, 14 is a shaft, 16 is a pressure origin sensor, 16a is a sensor arm, 17 is a paper setting switch, 18 is an operation switch, 19 is a stop switch, 20 is a printing pressure fine adjustment switch, 21 Is a control unit, 22 is a CPU, 23 is a ROM, 24 is a RAM, 25 is a transmission circuit, and 26 is a driver circuit.

Claims (4)

[Claims] 1. A blanket cylinder to which printing ink is transferred on a peripheral surface, and an impression cylinder rotatably supported by an eccentric part of an impression cylinder eccentric shaft so that the peripheral surface can be pressed against the peripheral surface of the blanket cylinder. A printing press for rotating the impression cylinder about the rotation center of the impression cylinder eccentric shaft to bring the printing paper into close contact with the peripheral surface of the blanket cylinder; A first member that can be integrally rotated and a second member that can be moved at a constant speed by a press-fitting motor are provided, and one sheet of printing paper is interposed between the blanket cylinder and the impression cylinder, and an elastic body is interposed. The first member is rotated in the press-fitting direction by the second member to bring the printing sheet into close contact with the blanket cylinder and the impression cylinder, and the first member is stopped and the first member is stopped. Required to deform the elastic body by a predetermined amount due to The reference pressure control amount is stored as a reference pressure control amount, and a correction for fine adjustment is added to this reference pressure control amount as a press-fitting control amount, and this press-fitting control is performed from the pressure origin at the time of printing using the printing paper. An automatic press-fitting method for a printing press, characterized in that a press-fitting motor that controls the rotation of the impression cylinder eccentric shaft is controlled by a value corresponding to the amount. 2. A position corresponding to a value obtained by subtracting a constant value k from a press-fitting control amount is set as a standby position, and rotation drive control of the constant value k is executed for the press-fitting motor only when a print sheet is supplied. As a result, the press-fitting process is speeded up, and the automatic press-fitting method for the printing press according to claim 1. 3. A blanket cylinder to which printing ink is transferred on a peripheral surface, and an impression cylinder rotatably supported by an eccentric portion of an impression cylinder eccentric shaft so that the peripheral surface of the blanket cylinder can be pressed against the peripheral surface. A printing machine that rotates the impression cylinder around the rotation center of the impression cylinder eccentric shaft to bring the printing paper into close contact with the peripheral surface of the blanket cylinder, and is fixed to the rotation center of the impression cylinder eccentric shaft. A first member, a second member rotatably supported by the pressure drum eccentric shaft about the center of rotation, and controlled to rotate at a constant speed by a press-fitting motor having a holding function; An elastic body that is provided between the first and second members and that accompanies the rotational movement of the first member in the press-fitting direction, and a sheet setting switch that activates the press-fitting motor in the press-fitting direction. , The pressure from the press-fitting motor Pressure origin sensor for detecting the initial position of the drive control system up to the reference pressure and a reference pressure for detecting that the elastic body is deformed by a predetermined amount due to a difference in predetermined rotation angle between the first and second members. A sensor and a press-fitting control unit, wherein the press-fitting control unit operates the reference pressure sensor from the time when the pressure origin sensor is set when the printing paper is inserted between the blanket cylinder and the press cylinder. The control amount of the press-fitting motor up to the time is taken in as the reference pressure control amount, and a value obtained by adding a correction for fine adjustment to this reference pressure control amount is calculated as the press-in control amount, and the actual amount using the printing paper is used. An automatic press-fitting device for a printing press, wherein the press-fitting control amount is given to the press-fitting motor during printing. 4. The press-fitting control unit rotates the press-fitting motor in the press-fitting direction from the press origin position by the amount corresponding to the standby amount, which is obtained by compiling a constant value k from the press-fitting control amount. A patent that is characterized in that the press-fitting motor is made to hold and wait, and the press-fitting motor is subjected to a rotational drive control in an amount corresponding to a constant value k in the press-fitting direction only when the printing paper is supplied to bring the press-fitting state. An automatic press-fitting device for a printing press according to claim 3.