JP2023065994A - Printer - Google Patents

Abstract

To provide a printer capable of suppressing the occurrence of labor of cleaning.SOLUTION: A printer includes: an ink roller group having a plurality of ink rollers for sending ink from an ink fountain to a plate cylinder; a blade 22 for scraping ink E on a prescribed ink roller 41 among the plurality of ink rollers; and a recovery container 25 for recovering the scraped ink E. The blade 22 is movable between a contact position for scraping the ink E on the ink roller 41 by coming in contact with the ink roller 41, and a separation position separated from the ink roller 41. The ink roller 41 is rotated in a first rotation direction when scraping ink on the ink roller 41 by the blade 22, and includes a control part F for controlling the position change of the blade 22 and the rotation of ink roller 41. The control part F changes a position of the blade 22 in a contact position to a separation position, and rotates the ink roller 41 in a second rotation direction opposite to the first rotation direction with the position change of the blade 22.SELECTED DRAWING: Figure 3

Description

The present invention relates to printing presses.

For example, Japanese Patent Laid-Open No. 2002-200002 describes that ink scraping is performed to quickly reduce the amount of ink (ink film thickness) on the ink roller in the ink section. In this ink scraping, a blade (also called a doctor blade) is brought into contact with the outer peripheral surface of a predetermined ink roller in a group of rotating ink rollers for a set period of time to scrape the ink on the ink roller and collect it in a collection container. do. After the set time has elapsed, the blade is moved to a separated position away from the outer peripheral surface of the ink roller.

However, when the blade is separated from the ink roller, as shown in FIG. This stringing 27 is a state in which ink extends and hangs down between the separated blade 22 and a predetermined ink roller 41, and is a phenomenon that occurs due to the viscosity of ink. The hanging ink E is torn off by its own weight and falls out of the recovery container 25 from between the tip 22F of the blade 22 and the outer peripheral surface 41A of the predetermined ink roller 41 (indicated by the dashed line in FIG. 6). ), or may wrap around and adhere to the back surface 22c of the blade 22, resulting in troublesome cleaning.

JP 2019-116012 A

SUMMARY OF THE INVENTION The present invention has been made to solve such problems, and an object thereof is to provide a printing press that can suppress the need for cleaning.

In order to achieve the above object, a printing press according to the present invention comprises an ink roller group having a plurality of ink rollers for feeding ink from an ink fountain to a plate cylinder, and a predetermined ink roller out of the plurality of ink rollers. and a collection container for collecting the ink scraped by the blade. and a spaced position apart from the roller, wherein the predetermined ink roller is configured to rotate in the first rotation direction when the ink on the predetermined ink roller is scraped off by the blade, and A control unit for controlling position change of the blade and rotation of the predetermined ink roller, wherein the control unit changes the position of the blade from the contact position to the separated position, and moves the predetermined ink roller along with the position change of the blade. It is characterized by rotating in a second direction of rotation opposite to the first direction of rotation.

According to the above configuration, the predetermined ink roller is rotated in the second rotation direction opposite to the first rotation direction as the blade is moved from the contact position where ink scraping is completed to the separated position. As a result, the ink forming the stringiness generated between the tip of the blade and the outer peripheral surface of the predetermined ink roller moves so as to be wound around the ink roller rotating in the second rotation direction. As a result, stringing between the tip of the blade and the outer peripheral surface of the predetermined ink roller is difficult to occur, or even if it occurs, it is quickly eliminated, so that the ink falls out of the collection container or falls on the back surface of the blade. It can be suppressed that it wraps around and adheres. In addition, it is possible to suppress the occurrence of printing defects caused by stringiness.

Further, in the printing press according to the present invention, the blade is configured to contact the predetermined ink roller in an inclined posture in which the tip side faces obliquely upward at the contact position, and the control unit moves the blade to the contact position. After the position is changed to scrape off the ink, the rotation of the predetermined ink roller in the first rotation direction is stopped, the stop is maintained for a predetermined time, and then the blade is moved from the contact position to the separation position. It may be configured to change the position.

As described above, after the position of the blade is changed to the contact position and the ink is scraped off, the ink remaining on the blade is stopped by stopping the rotation of the predetermined ink roller in the first rotation direction for a predetermined time. The scraped ink gradually flows downward and is collected in the collection container. As a result, when the position of the blade is changed from the contact position to the separated position after a predetermined period of time, stringing is less likely to occur between the tip of the blade and the outer peripheral surface of the predetermined ink roller.

Further, in the printing press according to the present invention, the separation distance between the tip of the blade and the outer peripheral surface of the predetermined ink roller at the separation position of the blade is such that ink does not drip between the blade and the predetermined ink roller. It may be set to a distance that can be maintained.

As described above, if the distance between the tip of the blade and the outer peripheral surface of the predetermined ink roller at the spaced position of the blade is set to a distance that allows the ink to be held between the blade and the predetermined ink roller without dripping. , the stringy ink can be prevented from tearing and dropping.

Also, in the printing press according to the present invention, it is desirable that the separation distance be set to any value between 0.5 mm and 3.0 mm.

According to the present invention, as the blade is moved from the contact position to the separated position, the predetermined ink roller is rotated in the second direction of rotation opposite to the first direction of rotation. It is possible to provide a printing press that can suppress the occurrence of

1 is a schematic vertical cross-sectional side view of a printing press of the present invention; FIG. It is an enlarged view of the ink supply section of the printing press. It is a figure explaining the state which makes a blade contact a predetermined ink roller, and is scraping off ink. FIG. 10 is a diagram illustrating a state in which the blade is moved away from a predetermined ink roller to stop the rotation of the predetermined ink roller after the ink is scraped off; FIG. 5 is a diagram for explaining a state in which a predetermined ink roller is rotated in a direction opposite to that during scraping from the state in FIG. 4 ; FIG. 10 is a diagram showing a conventional example in which stringing occurs between the tip of the blade and the outer peripheral surface of the ink roller;

A printing press according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a printing press with an ink scraping function, which is a sheet-fed offset printing press (hereinafter simply referred to as printing press). This printing press includes a paper feeding unit A for feeding sheets as printing paper one by one from a paper stacking table, a printing unit B for printing on the sheets from the paper feeding unit A, It has a surface treatment section C for surface-treating sheets printed by the printing section B, and a sheet discharge section D for discharging the sheets. Here, the printing section B has four printing units 5 so that four-color printing can be performed. A printing unit that can perform the above printing may be used. Further, the specific configuration of each part constituting the printing machine is not limited to that shown in FIG.

The printing unit 5 includes a plate cylinder 1 , a blanket cylinder 2 , an ink roller group 4 , an impression cylinder 3 and a transfer cylinder 6 . Although not shown, each of the impression cylinders 3 is provided with two grippers (one or three or more) in the circumferential direction for gripping the fed sheet with a gripper base and a claw. I have it. Reference numeral 7 denotes a paper feeding cylinder, which serves to receive the sheet conveyed on the feeder board 8 and mouth plate 9 from the swing arm 10 and transfer it to the impression cylinder 3 . The paper feed cylinder 7 and the swing arm 10 are also provided with a pawl base and a pawl. A printing plate (not shown) on which an image is formed is wound around the plate cylinder 1 and fixed.

The delivery section D consists of a chain transport device with two delivery cylinders and a gripper. That is, a first paper discharge cylinder 11 adjacent to the impression cylinder 3 of the surface treatment section C and a second paper discharge cylinder 12 adjacent thereto are provided, and are provided on the front side (upstream side) in the sheet conveying direction. An endless chain 15 is wound between a sprocket 13 and a sprocket 14 provided on the rear side (downstream side) of the sheet conveying direction. The chain 15 goes around in a regulated state. The sheet conveyed to the second discharge cylinder 12 is gripped by a plurality of chain grippers (not shown) fixed to the chain 15 at predetermined intervals and discharged.

As shown in FIG. 1, the surface treatment section C is provided with a varnish cylinder 16 that faces and abuts the impression cylinder 3 . Although not shown, an anilox roller is provided for contacting the varnish cylinder 16 to supply varnish. The surface treatment section C has a cylinder lifting device (not shown) that supports the varnish cylinder 16 so that it can move up and down with respect to the impression cylinder 3 .

FIG. 2 is an enlarged view of the ink supply section. An ink fountain roller 18 supplied with ink in the ink fountain 17 rotates counterclockwise in the figure, and supplies ink to the ink roller group 4 consisting of a large number of ink rollers located downstream via an adjacent ink call roller 19. supply. Although not shown in detail, the ink pickup roller 19 reciprocates alternately to contact and separate from the ink fountain roller 18 and the lateral roller 20 adjacent to the downstream side. That is, when the ink scooping roller 19 is in contact with the ink fountain roller 18 , the ink scooping roller 19 is separated from the lateral roller 20 . This reciprocating motion is also called an ink calling operation, and the more ink is called up, the more ink is supplied to the ink roller group 4 . Further, the ink fountain key K provided in the ink fountain roller 18 can be moved in the direction of the arrow S so that the ink fountain key K can be brought into contact with or separated from the ink fountain roller 18. The ink fountain roller 18 is configured to supply a large amount of ink to the ink fountain roller 18. The ink fountain key K is moved by being driven by an ink fountain key drive motor (not shown). Incidentally, the ink fountain key K can also be configured so that it can come into contact with and separate from the ink fountain roller 18 by rotating in the direction of arrow R indicated by an imaginary line. Reference numeral 21 shown in FIG. 2 denotes a cleaning nozzle for supplying the ink roller group 4 with a cleaning liquid for cleaning the ink roller group 4 .

A plurality of the ink fountain keys K are arranged side by side in the axial direction of the ink fountain roller 18 (see FIG. 2), that is, in the width direction of the printed material (direction perpendicular to the transport direction). The opening of the ink fountain key K with respect to the ink fountain roller 18 is determined for each ink fountain key according to the amount of ink required based on the printed image.

To the left of one predetermined ink roller 41 (in FIG. 2, the ink roller positioned second from the bottom on the left end) in the ink roller group 4, there is a roller for reducing the film thickness of the ink on the predetermined ink roller 41. blade (also referred to as a doctor blade) 22 is provided. The blade 22 is configured to rotate in the arrow T direction by the extension and contraction of an air cylinder 23, which is an example of an actuator. Specifically, the tip of the piston rod 23A of the air cylinder 23 is connected to one end of the arm 24, and the other end of the arm 24 is linked to the lower end of the collection container 25 to which the blade 22 is attached. Therefore, by extending the air cylinder 23 in FIG. 2, the recovery container 25 is rotated clockwise about the axis X parallel to the rotation axis of the predetermined ink roller 41 to contact the predetermined ink roller 41 at the contact position (see FIG. 2). 3), and by shortening the air cylinder 23 opposite to the above, the collection container 25 is rotated counterclockwise about the axis X parallel to the rotation axis of the predetermined ink roller 41, and the ink roller 41 The blade 22 is configured to be movable between the separated positions (see FIGS. 4 and 5). The dimension of the blade 22 in the width direction (the direction penetrating through the plane of FIG. 2) is set to be longer than the dimension of the predetermined ink roller 41 in the width direction. When feeding ink, the predetermined ink roller 41 is configured not only to rotate but also to move in the direction of the rotation axis (the direction penetrating the plane of FIG. 2). The dimension in the width direction of the blade 22 is set so that it can be covered. The widthwise dimension of the collection container 25 is also set according to the widthwise dimension of the blade 22 .

Further, as shown in FIG. 3, the blade 22 includes a flat blade portion 22A that contacts the outer peripheral surface of the predetermined ink roller 41, and a support portion 22B that supports the lower side portion of the blade portion 22A. The portion 22B is fixed by a plurality of screws 26 to the inner side of an upper wall portion 25a that constitutes the collection container 25 and will be described later. The blade portion 22A is made of a hard synthetic resin and has a thinner thickness toward the tip, so that the ink can be reliably scraped off. The support portion 22B has an inclined surface 22b whose upper end portion is positioned closer to the predetermined ink roller 41 than the upper end side. We are making it possible to guide movement.

As shown in FIG. 3, the collection container 25 has a substantially V-shaped cross section, and includes a plate-like first inclined wall portion 25A on the side of the predetermined ink roller 41 and a plate-like wall portion 25A on the side spaced from the predetermined ink roller 41. and a bottom wall portion 25C curved in a substantially U-shape projecting downward connecting the lower end of the first inclined wall portion 25A and the lower end of the second inclined wall portion 25B. ing. The first inclined wall portion 25A includes a linear upper wall portion 25a to which the blade 22 is attached, and a lower wall portion 25b that linearly extends from the lower end of the upper wall portion 25a to the bottom wall portion 25C. The upper wall portion 25a is inclined toward the predetermined ink roller 41 side with respect to the lower wall portion 25b. When the tip of the blade 22 is in contact with the outer peripheral surface of the predetermined ink roller 41 , the upper end of the upper wall portion 25 a is separated from the outer peripheral portion of the predetermined ink roller 41 .

The blade portion 22A of the blade 22 configured as described above is configured to contact the outer peripheral surface of the predetermined ink roller 41 in a direction intersecting with the ink roller 41, that is, in an inclined posture in which the tip side faces obliquely upward. When scraping ink, the predetermined ink roller 41 is rotated counterclockwise so that the ink E on the predetermined ink roller 41 moves toward the blade 22 at the contact position of the blade portion 22A of the blade 22, as shown in FIG. rotated around. As a result, the ink E on the predetermined ink roller 41 can be scraped off by the blade portion 22A of the blade 22 . Further, the ink E scraped off by the blade portion 22A is deposited on the upper surface (front surface) 22a of the blade portion 22A which is inclined so that the upper end side is positioned closer to the predetermined ink roller 41 (in FIG. 3, it faces obliquely upward to the right). It moves to the recovery container 25 side by its own weight.

The printing press has a control section F (see FIG. 3) for controlling the position change of the blade 22 and the rotation of the predetermined ink roller 41 . The controller F changes the position of the blade 22 from the contact position to the separated position, and rotates the predetermined ink roller 41 so as to rotate the predetermined ink roller 41 in the clockwise direction opposite to the counterclockwise direction as the position of the blade 22 is changed. An instruction signal is output to a motor (not shown) that drives and rotates the . The counterclockwise rotation corresponds to the first rotation direction of the present invention, and the clockwise rotation corresponds to the second rotation direction of the present invention.

In addition, after changing the position of the blade 22 to the contact position to scrape off the ink, the control unit F stops the rotation of the predetermined ink roller 41, maintains the stop for a predetermined time, and then brings the blade 22 into contact. It is repositioned from the position to the spaced position (see FIG. 4). As described above, by stopping the rotation of the predetermined ink roller 41 for a predetermined time, the ink on the blade 22, especially the tip 22F, gradually flows downward. As a result, when the position of the blade 22 is changed from the contact position to the separated position after a predetermined period of time, stringing between the tip 22F of the blade 22 and the outer peripheral surface 41A of the predetermined ink roller 41 is less likely to occur or occurs. Even if it does, the amount of ink that causes stringiness can be reduced. A suitable value for the predetermined time (the time during which the rotation of the ink roller 41 is maintained to be stopped for a predetermined time) varies depending on the viscosity of the ink. In general, UV ink has higher viscosity and lower fluidity than oil-based ink, so it is necessary to lengthen the predetermined time. Therefore, if UV ink is used, it is preferable to set the time to about 10 seconds. Further, the predetermined time (stop time) of the predetermined ink roller 41 can be set to an arbitrary time. For example, the stop time for UV ink is set to 10 seconds, and the stop time for oily ink is set to a time shorter than 10 seconds. You may enable it to set.

As a result of experiments conducted by the inventors of the present application, the separation distance L (see FIG. 4) between the tip 22F of the blade 22 and the outer peripheral surface 41A of the predetermined ink roller 41 at the separation position of the blade 22 is 0.5 mm to 3.0 mm. It was found that it is preferable to set the value to an arbitrary value between , and it is particularly preferable to set the value to about 2.0 mm. In this embodiment, the separation distance L is 2.0 mm. The separation distance L is a distance at which the stringy ink E between the tip 22F of the blade 22 and the outer peripheral surface 41A of the predetermined ink roller 41 can be held as shown in FIG. 4 without dripping (see FIG. 6). FIG. 4 shows an example of a state in which the ink E is stretched substantially linearly between the blade 22 and the predetermined ink roller 41 and held.

Next, the adjustment of the thickness of the ink by scraping off the ink E on the predetermined ink roller 41 with the blade 22 will be described.

By pressing an ink scraping button or switch (not shown), the controller F extends the air cylinder 23 to move the blade 22 from the separated position in FIG. 2 to the contact position. A signal is output to the air cylinder 23 to cause the air cylinder 23 to The extension operation of the air cylinder 23 rotates the collection container 25 clockwise to bring the blade 22 into contact with the outer peripheral surface 41A of the predetermined ink roller 41 rotating counterclockwise (see FIG. 3). FIG. 3 shows a state in which the ink E moving toward the blade 22 is scraped off and collected in the collection container 25 . When the ink E is scraped off by the blade 22 and the film thickness adjustment is completed, the controller F stops the rotation of the predetermined ink roller 41 while the blade 22 remains at the contact position. The suspension is maintained for a predetermined time (for example, 10 seconds for UV ink). After a predetermined time has passed since the stop, the controller F moves the blade 22 from the contact position to the separated position (see FIG. 4). When the blade 22 is positioned at the separated position, the controller F outputs an instruction signal to the motor that drives and rotates the predetermined ink roller 41 so as to rotate the predetermined ink roller 41 clockwise as opposed to counterclockwise. The amount of rotation of the predetermined ink roller 41 in the clockwise direction at this time should be equal to or greater than the rotation angle necessary for the ink in the stringy state to be wound around the predetermined ink roller 41 . For example, 30° or more is sufficient.

As described above, by rotating the predetermined ink roller 41 in the clockwise direction opposite to the counterclockwise direction, stringiness is formed between the tip 22F of the blade 22 and the outer peripheral surface 41A of the predetermined ink roller 41. The ink E is pulled by the predetermined ink roller 41 and moved so as to be wound up by the predetermined ink roller 41 (see FIG. 5). As a result, stringing between the tip 22F of the blade 22 and the outer peripheral surface 41A of the predetermined ink roller 41 is difficult to occur, or even if it occurs, it is quickly eliminated. It is possible to prevent the particles from falling out of the recovery container 25 from the space between the roller 41 and the outer peripheral surface 41A, or from wrapping around and adhering to the back surface 22c (see FIG. 5) of the cutting edge 22A of the blade 22.

In this embodiment, after the blade 22 moves to the separated position, the predetermined ink roller 41 is rotated clockwise, which is opposite to the counterclockwise direction. The rotation of the predetermined ink roller 41 in the opposite direction may be started (simultaneously with the start), or at any position after the blade 22 starts moving to the separated position until it is positioned at the separated position.

It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

In the above-described embodiment, when scraping off the ink on the predetermined ink roller 41 to adjust the film thickness of the ink, the tip 22F of the blade 22 and the outer peripheral surface 41A of the predetermined ink roller 41 are prevented from being stringy. , the position change of the blade 22 and the rotation of the predetermined ink roller 41 are controlled by the controller F. The position change of the blade 22 and the rotation of the predetermined ink roller 41 may be controlled by the controller F so that stringing is less likely to occur between the tip 22F of the blade and the outer peripheral surface 41A of the predetermined ink roller 41 .

Further, in the above-described embodiment, the ink is scraped by the ink roller 41 positioned second from the left end of the ink roller group 4, but the ink is scraped by the other ink rollers of the ink roller group 4. It may be a configuration.

Further, in the above embodiment, the position of the blade 22 is changed by rotating the collection container 25, but the position of the blade 22 may be changed by sliding the collection container 25 linearly.

Further, in the above-described embodiment, the blade portion 22A of the blade 22 is configured in a flat plate shape, but it may be configured in a curved shape.

DESCRIPTION OF SYMBOLS 1... Plate cylinder, 2... Blank cylinder, 3... Impression cylinder, 4... Ink roller group, 5... Printing unit, 6... Transfer cylinder, 7... Paper supply cylinder, 8... Feeder board, 9... Mouth plate, 10... Swing Arm 11 First discharge cylinder 12 Second discharge cylinder 13, 14 Sprocket 15 Chain 16 Varnish cylinder 17 Ink fountain 18 Ink fountain roller 19 Roller 20 Roller roller 21 Cleaning nozzle 22 Blade 22A Cutting edge 22B Supporting part 22F Tip 22a Upper surface (surface) 22b Inclined surface 22c Back surface 23 Air cylinder 23A Piston Rod 24 Arm 25 Collection container 25A First inclined wall 25B Second inclined wall 25C Bottom wall 25a Upper wall 25b Lower wall 26 Screw 27 String drawing 41 Predetermined ink roller 41A Peripheral surface A Paper feeding unit B Printing unit C Surface treatment unit D Paper discharge unit E Ink F Control unit K Ink fountain key , L...separation distance, S, T, R...arrows, X...axis center

Claims (4)

An ink roller group having a plurality of ink rollers for sending ink from an ink fountain to a plate cylinder, a blade for scraping ink on a predetermined ink roller among the plurality of ink rollers, and a blade for scraping ink scraped off by the blade A collection container is provided for collecting ink, wherein the blade is configured to be movable between a contact position at which ink on the predetermined ink roller is scraped off by contacting the predetermined ink roller and a separation position at a distance from the predetermined ink roller, The predetermined ink roller is configured to rotate in a first rotational direction when ink on the predetermined ink roller is scraped off by the blade, and a control for controlling the position change of the blade and the rotation of the predetermined ink roller. having a department,
The control unit changes the position of the blade from the contact position to the separated position, and rotates the predetermined ink roller in a second direction of rotation opposite to the first direction of rotation as the position of the blade is changed. A printing machine characterized by: The blade is configured to come into contact with the predetermined ink roller in a tilted posture in which the tip side faces obliquely upward at the contact position, and the control unit changes the position of the blade to the contact position to scrape off the ink. after contacting the blade, the rotation of the predetermined ink roller in the first rotation direction is stopped, and after the stoppage is maintained for a predetermined time, the position of the blade is changed from the contact position to the separation position. 1. The printing press according to 1. The distance between the tip of the blade and the outer peripheral surface of the predetermined ink roller at the spaced position of the blade is set to a distance that allows ink to be held between the blade and the predetermined ink roller without dripping. 3. The printing press according to claim 1 or 2. 4. The printing press according to claim 3, wherein the separation distance is set to any value between 0.5 mm and 3.0 mm.

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