JP2002086875A - Multicolor printing equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To contrive to improve working efficiency by eliminating waste of time in a plate feeding process or the like and to facilitate the controlling of the positional setting of printing drums by a method wherein the optimum positional relationship of the rotary directions of a plurality of the printing drums is established in order to obtain a favorable printing image. SOLUTION: Let A be the center of a printing impression cylinder 4, let B be the center of a printing drum 6 and let C be the center of a printing drum 8. Let θ be the angle between lines that connect the centers B and C of the printing drums 6 and 8 with the center A of the printing impression cylinder 4, the home positions in rotary direction of the two printing drums 6 and 8 are set staggered by an angle of (2×θ).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multicolor printing apparatus such as a stencil printing apparatus capable of performing multicolor printing in one pass (one sheet conveyance), and more particularly, to a plurality of printing apparatuses around a printing cylinder. The present invention relates to a multicolor printing apparatus in which a printing drum is arranged.

[0002]

2. Description of the Related Art As a multicolor printing apparatus of this type, for example, as described in Japanese Patent Application Laid-Open No. 4-163801, a double-cylinder stencil having a plurality of printing drums arranged around a single impression cylinder. Printing devices are known. A clamper for holding the leading end of the printing paper is provided on a part of the outer periphery of the impression cylinder, and the ink image of each printing drum is printed on the printing paper by one transfer of the printing paper with the rotation of the impression cylinder. It is transferred and multicolor overprinted. Although it is not a configuration in which a plurality of printing drums are arranged around one printing pressure cylinder, Japanese Patent Publication No. 2983661 discloses a plurality of printing drums arranged at equal intervals in the vertical direction and a plurality of printing drums corresponding to each printing drum. A plurality of press rollers individually provided at equal intervals in the vertical direction, plate discharging means also provided individually corresponding to each printing drum, and one plate making / pressing machine provided on the uppermost printing drum A multicolor printing apparatus having a plate feeding means and a belt wound between press rollers is described. The belt is provided with the same number of clampers as the number of printing drums at equal intervals.In the plate feeding process, the plate-making master supplied from the plate making / plate feeding means is clamped by the clamper and conveyed by the belt rotation. The print drum is released when it reaches the position of the corresponding print drum, and is wound while being clamped by the clamper of the print drum. Each plate discharging means is provided at the same position with respect to each printing drum.Because the plate-making master is transferred to each printing drum on the same straight line by belt conveyance, it is transferred to a plurality of printing drums adjacent to each other. On the other hand, the plate feeding point and the plate discharging point of the plate making / plate feeding means and the plate discharging means are the same without being shifted. The configuration described in Japanese Patent Publication No. 7-17083 has the same configuration.

[0003]

In the prior art relating to the arrangement of a plurality of printing drums around one impression cylinder,
There is no clear description of the positional relationship between the printing drums in the rotational direction. There is no description as to whether an attaching / detaching operation, an on / off operation of printing pressure during printing, a plate feeding operation, or a plate discharging operation is performed. According to Japanese Patent Publication No. 2983661 and Japanese Patent Publication No. Hei 7-17083, plate feeding and plate discharging operations cannot be performed simultaneously at the same timing.
Even if the timing is shifted, it is necessary to temporarily stop the rotation of the printing drum during plate feeding, which increases the total plate feeding time and reduces the efficiency of the printing operation.

In view of the above, the present invention finds an optimal rotational direction positional relationship between a plurality of printing drums in a configuration in which a plurality of printing drums are arranged around one printing pressure cylinder, and shortens plate feeding and plate discharging times. It is an object of the present invention to provide a multi-color printing apparatus capable of improving printing efficiency.

In order to achieve the above object, according to the first aspect of the present invention, one printing pressure cylinder having a clamper for holding the leading end of printing paper on a part of the outer circumference, and the printing pressure cylinder is disposed around the printing pressure cylinder. A multi-color printing apparatus having a plurality of printing drums and capable of multi-color overprinting, wherein a line connecting the center of two adjacent printing drums of the plurality of printing drums and the center of the printing cylinder is formed. When the angle is θ, the amount of deviation in the rotation direction between the two adjacent printing drums is set based on the angle θ.

According to a second aspect of the present invention, in the multicolor printing apparatus according to the first aspect, the two adjacent printing drums are set such that their home positions in the rotation direction are shifted by an angle of 2 × θ. Has been adopted.

According to a third aspect of the present invention, in the multicolor printing apparatus according to the first aspect, the two adjacent printing drums have a home position in the rotation direction at the time of attachment / detachment of two.
It is configured to be shifted by an angle of xθ.

According to a fourth aspect of the present invention, in the multicolor printing apparatus according to the first aspect, plate supply means for supplying a plate-making master is provided for each of the plurality of printing drums. The plate feeding points on two adjacent printing drums are set to be shifted by an angle of 2 × θ.

According to a fifth aspect of the present invention, in the multicolor printing apparatus according to the first aspect, plate discharging means for separating a used master and discharging the plate is provided for each of the plurality of printing drums. In addition, a configuration is adopted in which the peeling points on two adjacent printing drums are set to be shifted by an angle of 2 × θ.

According to a sixth aspect of the present invention, in the multicolor printing apparatus according to the first aspect, the printing drum is rotated by a driving source, and the printing drum is rotated by transmission of a driving force from the printing cylinder. A top and bottom adjustment mechanism that is driven and adjusts a position shift in a top and bottom direction that is a conveyance direction of the printing paper corresponding to each printing drum is provided, and the timing is adjusted by the driving source to rotate the two adjacent printing drums. The home position in the direction is set so as to be shifted by an angle of 2 × θ.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. First, an outline of the overall configuration of a multicolor stencil printing apparatus as a multicolor printing apparatus according to the present embodiment will be described with reference to FIG. As shown in FIG. 1, the multicolor stencil printing machine 2 includes a printing cylinder 4 and one of the printing press cylinders 4 arranged around the printing cylinder 4.
The printing drum 6 for the second color, the printing drum 8 for the second color, the plate discharging means 10 provided for the printing drum 6, and the plate feeding means 1
2 and a plate discharging means 1 provided corresponding to the printing drum 8
4, plate supply means 16, paper supply means 18, separation claw 20 for separating printed printing paper P from impression cylinder 4, paper discharge conveyance means 22 for conveying separated printing paper P, printing It has a discharge tray 24 on which the completed printing paper P is discharged and stacked.

A concave portion 4a is formed in the impression cylinder 4 to avoid interference with the printing drums 6 and 8. One end of the concave portion 4a in the rotation direction holds the leading end of the printing paper P. Is provided. The paper feeding means 18
The paper feed tray 28 on which the printing paper P is loaded and stored, and the paper feed roller 3
0, a separation roller 32, and a separation member 34 such as a separation pad urged in the direction of the arrow, and separates and feeds the stacked printing papers P one by one from the top. .
The fed printing paper P is temporarily stopped by the pair of registration rollers 36, and is sent to the clamper 26 of the impression cylinder 4 after correcting the oblique displacement or the like here.

The printing drum 6 has a clamper 3
Eight. The leading end of the master M1 supplied from the plate supplying means 12 is clamped by the clamper 38, and the master M1 is wound around the outer peripheral surface of the printing drum 6 as the printing drum 6 rotates. The printing drum 6 has a known drum configuration. That is, although not shown, one or more mesh screen layers are provided on the outer peripheral surface of the porous cylindrical substrate, and the master M1 is wound around the outer peripheral surface. An ink supply means 40 is provided inside the cylindrical substrate, and the ink supplied by the ink supply means 40 oozes out of the perforated portion of the master M1 by the pressing force of the impression cylinder 4, and is printed on the printing paper P. It is transferred to. The ink supply means 40 includes an ink roller 42.
And a doctor roller 44, and the ink roller 4
The ink is supplied to a wedge-shaped ink reservoir 46 formed between the second roller 2 and the doctor roller 44 by using an unillustrated rotation support shaft of the printing drum 6 as an ink supply pipe, and the ink stored in the ink reservoir 46 is discharged by the doctor roller 44. The ink is supplied to the ink roller 42 while the thickness is regulated to be constant. The ink supplied to the ink roller 42 is supplied to the inner surface of the cylindrical substrate.

The printing drum 8 also has a clamper 48 on a part of the outer periphery. The leading end of the master M2, which has been made and supplied from the plate supplying means 16, is clamped by the clamper 48,
With the rotation of the printing drum 8, the master M2 is wound around the outer peripheral surface of the printing drum 8. The printing drum 8 also has the same known configuration as the printing drum 6. The ink supply means 50 provided inside the printing drum 8 is
2 and a doctor roller 54, and ink is supplied to a wedge-shaped ink reservoir 56 formed between the ink roller 52 and the doctor roller 54 using an unillustrated rotary support shaft of the printing drum 8 as an ink supply pipe. The ink stored in the ink pool 56 is supplied to the ink roller 52 while the thickness thereof is regulated by the doctor roller 54 to a constant value. The ink supplied to the ink roller 52 is supplied to the inner surface of the cylindrical substrate.

The printing paper P is conveyed with the rotation of the impression cylinder 4, the first color ink image is transferred by pressing the printing drum 6, and the second color ink image is subsequently transferred by pressing the printing drum 8. Transcribed. When the second color ink image is transferred, the clamper 26 of the impression cylinder 4 is moved at a predetermined timing.
Is opened, and the leading end of the printing paper P is opened. The printing paper P whose leading end is opened is separated from the impression cylinder 4 by the separation claw 20, and is conveyed by the paper discharging and conveying means 22 to the paper discharging table 24.
Will be stacked. Although not shown, the paper discharging and conveying means 22 has a suction fan, and is configured to convey while suctioning by suction.

When a predetermined number of sheets have been printed and the next document is to be printed, the used master on the printing drum 6 is peeled off by the plate discharging means 10 and the plate feeding means 12 performs the printing based on the next document. The new master that has been made is wound around the outer peripheral surface of the printing drum 6. On the other hand, in the printing drum 8, the used master on the printing drum 8 is peeled off by the plate discharging device 14, and a new master made by the plate feeding device 16 based on the next original is wound around the outer peripheral surface of the printing drum 8. Is done.

In the present embodiment, in FIG.
A, the center of the printing drum 6 is B, the center of the printing drum 8 is C, and the angle formed by a line connecting the centers B and C of the printing drums 6 and 8 and the center A of the impression cylinder 4 is θ. In this case, the amount of displacement in the rotational direction between two adjacent printing drums 6, 8 is set based on the angle θ (claim 1). This will be specifically described below. First, the position of the clamper 38 of the print drum 6 and the position of the clamper 48 of the print drum 8 are shifted by an angle of (2 × θ) in the rotation direction. This means that the two print drums 6 and 8 are set such that their home position in the rotation direction (the position of the leading end of the image of the master wound on the drum) is shifted by an angle of (2 × θ). (Claim 2), and the two print drums 6 and 8 have their home position positions in the rotational direction at the time of attachment and detachment set to be shifted by an angle of (2 × θ). (Claim 3). This (2 ×
θ), the image position of the printing drum 6 and the image position of the printing drum 8 with respect to the printing paper P conveyed by the impression cylinder 4 are matched, and the position between the printing drums 6 and 8 is maintained. It is possible to easily determine whether the relationship is correct.

Further, the plate feeding point SP1 of the printing drum 6 (the position at which the master is supplied by the plate feeding means 12) SP1 and the plate feeding point SP2 of the printing drum 8 are set to be shifted by an angle of (2 × θ). (Claim 4). Also, the plate discharging point EP1 on the printing drum 6 and the plate discharging point EP2 on the printing drum 8 are set so as to be shifted by an angle of (2 × θ). This (2 ×
θ), the plate feeding can be simultaneously started for the two printing drums 6 and 8 at the same timing, and the plate discharge can be simultaneously started for the two printing drums 6 and 8 at the same timing. .

FIG. 1 shows a state in which the printing drum 6 is located at a home position for attachment / detachment. In this state, the printing drum 8 cannot be attached to / detached from an apparatus main body (not shown). To make the printing drum 8 detachable,
The printing drum 8 is further rotated from the state shown in FIG. 1 by the angle θ in the direction of the arrow to obtain the state shown in FIG. By rotating the print drum 8 by the angle θ, the print drum 8 is located at the home position for attachment and detachment. FIG. 3 shows a plate feeding start state of the printing drums 6 and 8. As described above, the plate feeding point SP1 on the printing drum 6 and the plate feeding point SP2 on the printing drum 8 are set to be shifted by an angle of (2 × θ), so that plate feeding can be started simultaneously. it can. Although not shown, printing can be started simultaneously on the printing drums 6 and 8 for the same reason.

As shown in FIG. 4, the driving structure of the printing cylinder 4 and the printing drums 6 and 8 in this embodiment is such that the main motor 60 as a driving source drives the printing cylinder 4 via a belt 62.
Are driven to rotate, and the printing drums 6 and 8 are driven to rotate by transmission of the driving force from the printing cylinder 4 via the belts 64 and 66, respectively. The print drums 6 and 8 are provided with top-and-bottom adjustment mechanisms 68 and 70, respectively, for adjusting a position shift in a top-to-bottom direction which is a transport direction of the printing paper P. The top and bottom adjustment mechanisms 68 and 70 have a well-known configuration including a planetary gear, and for example, a configuration described in JP-A-11-58918 can be adopted. The control means (not shown) controls the main motor 60 to control the top-and-bottom adjustment mechanisms 68 and 70, so that the home positions of the two printing drums 6 and 8 in the rotational direction are automatically shifted by an angle of 2 × θ. It is set (claim 6).

FIG. 5 is a diagram showing a positional relationship of an example in which three printing drums are arranged around the printing cylinder 4. In the present embodiment, the print drum 5 is the first color, the print drum 6 is the second color,
The printing drum 8 is a third color. Also in this case, the angle formed by the line connecting the center D of the printing drum 5 and the center B of the printing drum 6 with the center A of the impression cylinder 4 is set to θ, and the printing with the printing drum 5 is performed based on this. The positional relationship of the drum 6 is set in the same manner as in the above embodiment. In FIG.
Reference numeral 7 denotes an ink roller of the printing drum 5, and reference numeral 9 denotes a clamper. In FIG. 5, the clamper and the like of the printing cylinder 4 are omitted.

[0022]

According to the first aspect of the present invention, when an angle formed by a line connecting the center of two adjacent printing drums of the plurality of printing drums and the center of the impression cylinder is θ, Since the amount of displacement in the rotational direction between the two adjacent printing drums is set based on the angle θ, image displacement can be suppressed with high accuracy. Further, since the mutual positional relationship between the plurality of printing drums can be simplified, the adjustment and control of the positional deviation can be facilitated.

According to the second aspect of the present invention, the two adjacent printing drums are configured such that their home positions in the rotating direction are set to be shifted by an angle of 2 × θ. It is possible to easily adjust and control the displacement while ensuring the attachment and detachment.

According to the third aspect of the present invention, the two adjacent printing drums are configured such that their home positions in the rotating direction at the time of attachment / detachment are set to be shifted by an angle of 2 × θ. While securely attaching and detaching the print drum,
It is possible to easily adjust and control the displacement.

According to the fourth aspect of the present invention, plate supply means for supplying a plate-making master is separately provided for each of the plurality of print drums, and plate supply means for two adjacent print drums are provided. Since the points are set so as to be shifted by an angle of 2 × θ, plate feeding can be started simultaneously in a plurality of printing drums, thereby shortening the time in the plate feeding process and improving work efficiency. Can be.

According to the fifth aspect of the present invention, the plate discharging means for separating the used master and discharging the plate is provided separately for each of the plurality of printing drums, and the separation is performed between two adjacent printing drums. Since the points are set so as to be shifted by an angle of 2 × θ, plate discharging can be started simultaneously in a plurality of printing drums, and the time in the plate discharging process can be shortened to improve work efficiency. .

According to the sixth aspect of the present invention, the printing cylinder is driven to rotate by the driving source, and the printing drum is driven to rotate by transmission of the driving force from the printing cylinder. A top-bottom adjustment mechanism is provided for adjusting the displacement in the top-bottom direction, which is the direction in which the printing paper is conveyed, and the timing is adjusted by the drive source so that the home position in the rotation direction of two adjacent printing drums is 2 × θ. Since the configuration is set so as to be shifted by the angle, the setting of shifting by the angle of 2 × θ can be easily and reliably performed.

[Brief description of the drawings]

FIG. 1 is a schematic front view of a multicolor stencil printing apparatus as a multicolor printing apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic front view of a state where a second color printing drum is positioned at a home position.

FIG. 3 is a schematic front view showing a simultaneous start state of plate feeding.

FIG. 4 is a schematic front view showing a driving configuration.

FIG. 5 is a schematic front view of a multicolor stencil printing apparatus according to another embodiment.

[Explanation of symbols]

 Reference Signs List 4 printing impression cylinder 5, 6, 8 printing drum 10, 14 plate discharging means 12, 16 plate feeding means 26 clamper 60 main motor 68, 70 top-bottom adjustment mechanism P printing paper

Claims (6)

[Claims] 1. A multi-color printing apparatus comprising: a printing cylinder having a clamper at a part of an outer periphery thereof for holding a leading end of a printing sheet; and a plurality of printing drums arranged around the printing cylinder. In a multi-color printing apparatus capable of, when an angle formed by a line connecting the center of two adjacent printing drums of the plurality of printing drums and the center of the impression cylinder is θ, the angle θ is used as a reference. A multicolor printing apparatus, wherein the amount of displacement in the rotation direction between two adjacent printing drums is set. 2. The multicolor printing apparatus according to claim 1, wherein the two adjacent printing drums are set such that their home positions in the rotation direction are shifted by an angle of 2 × θ. Multicolor printing equipment. 3. The multi-color printing apparatus according to claim 1, wherein the two adjacent printing drums are set such that their home positions in the rotation direction at the time of attachment / detachment are shifted by an angle of 2 × θ. A multicolor printing apparatus characterized by the above-mentioned. 4. A multi-color printing apparatus according to claim 1, wherein plate-feeding means for feeding a plate-making master is separately provided corresponding to each of said plurality of printing drums. A multicolor printing apparatus, wherein plate feeding points on a drum are set to be shifted by an angle of 2 × θ. 5. A multi-color printing apparatus according to claim 1, wherein a plate discharging means for separating a used master and discharging the plate is provided for each of said plurality of printing drums. 2 peel points on print drum
A multicolor printing apparatus, which is set so as to be shifted by an angle of xθ. 6. A multicolor printing apparatus according to claim 1, wherein said printing drum is driven to rotate by a driving source, and said printing drum is driven to rotate by transmission of a driving force from said printing drum. A top-bottom adjustment mechanism is provided to adjust the position shift in the top-to-bottom direction, which is the direction in which the printing paper is conveyed, and the timing is adjusted by the drive source so that the home position in the rotation direction of the two adjacent printing drums is adjusted. A multicolor printing apparatus characterized in that it is set so as to be shifted by an angle of 2 × θ.