JP5186147B2 - Printing device - Google Patents

Description

  The present invention relates to a printing apparatus that sandwiches a sheet between a plate cylinder and a press roller and transfers an image of the plate cylinder to the sheet, and more particularly to a printing apparatus having a cleaning mechanism that cleans ink adhering to the press roller. is there.

  Conventionally, in the above printing apparatus, stencil printing apparatuses provided with a cleaning mechanism for cleaning a press roller using a blade are disclosed in Patent Document 1 and Patent Document 2.

Also, Patent Document 3 and Patent Document 4 disclose a printing apparatus that coats the outer peripheral surface of rubber that is a press roller member with silicon rubber, a fluorine compound layer, or the like in order to facilitate cleaning of the press roller with a blade. Yes.
Japanese Patent Laid-Open No. 01-206049 JP 2002-137523 A Japanese Patent Laid-Open No. 10-157083 JP 2004-58384 A

  The press roller presses the paper against the plate cylinder in order to transfer the ink onto the paper, and the outer peripheral surface is usually formed of rubber. Here, if the blade is brought into contact with the press roller whose outer peripheral surface is made of rubber and cleaning is attempted, a large frictional force is generated, and the blade is involved, or the press roller becomes slower than the rotation of the plate cylinder. As a result, a print image shift or a master shift occurs. Therefore, in order to reduce the friction of the outer peripheral surface of the press roller, it has been considered to configure the outer peripheral surface with silicon rubber, a fluorine compound layer, or the like. However, when coating the outer peripheral surface of the press roller, there is a problem of durability of the coating layer.

  Accordingly, an object of the present invention is to provide a printing apparatus that is excellent in durability and capable of performing high-quality printing in order to solve the above problems.

The invention according to claim 1 is a printing apparatus in which a sheet is pressed against a plate cylinder by a press roller for printing, and includes a cleaning mechanism for cleaning the press roller. The press roller includes a roller shaft and an outer periphery of the roller shaft. a rubber layer provided on has a roller body, and a metal layer formed on the outer periphery of the roller body, wherein the cleaning mechanism has a blade for scraping ink adhered to the metal layer, wherein The surface roughness of the metal layer is characterized in that the Ry value is 7 μm or less . Here, the Ry value indicates the maximum height of the surface roughness.

In the above invention, a metal layer is formed on the outer peripheral surface of the press roller, and the ink adhering to the metal layer is scraped off by the blade of the cleaning mechanism. Of course, it is possible to prevent transfer, and by making the outer peripheral surface of the press roller a metal layer, while reducing the wear of the press roller by the blade and maintaining the durability of the press roller, Printing quality can also be maintained.
In the above invention, the surface roughness of the metal layer is such that the Ry value is 7 μm or less, so that the blade can easily come into contact with the metal layer, and the amount of ink remaining after scraping can be reduced. .

  The invention according to claim 2 is characterized in that, in the invention according to claim 1, the thickness of the metal layer is more than 20 μm and less than 400 μm.

  In the above invention, since the thickness of the metal layer is more than 20 μm and less than 400 μm, when the outer peripheral surface of the press roller has a metal layer, printing can be performed without losing the balance between the pressing force of the plate cylinder and the press roller. The printing quality can be kept high.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein the hardness of all the press rollers including the press roller and the metal layer on the outer peripheral surface thereof is 65Hs or more and less than 95Hs. It is characterized by that.

  In the above invention, since the hardness of all the press rollers including the press roller and the metal layer on the outer peripheral surface thereof is set to 65Hs or more and less than 95Hs, when the outer peripheral surface of the press roller has a metal layer, the plate cylinder Printing can be performed without losing the balance of the pressing force of the press roller and the printing quality can be maintained high.

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the press roller is driven so that a peripheral speed of the press roller is equal to a peripheral speed of the plate cylinder. It is characterized by being driven by a mechanism.

  In the above invention, since the peripheral speed of the press roller is driven so as to be the same as the peripheral speed of the plate cylinder, it is possible to prevent displacement of the print image due to a delay in the peripheral speed of the press roller with respect to the plate cylinder. High quality can be maintained.

The invention according to claim 5 is the invention according to any one of claims 1 to 4 , wherein the printing apparatus has a double-sided printing function.

  In the above invention, the double-sided printing apparatus prints one side of the paper in the first printing process, and in the next printing process, the press roller comes into contact with one side of the printed paper, so that the ink easily adheres to the press roller. However, the effect of the present invention capable of preventing ink transfer can be further exhibited as compared with a normal printing apparatus.

[First Embodiment]
1 to 3 show an embodiment of a stencil printing apparatus according to the present invention, and the present invention will be described based on these drawings.

FIG. 1 is a schematic side view of a stencil printing apparatus according to the present invention. This printing apparatus includes a paper feeding device 1 that feeds paper, a paper ejection device 2 that discharges paper, and plate making that makes stencil paper. Apparatus 3, plate cylinder 4 on which stencil paper is mounted and printing is performed, press roller 5 for pressing the sheet against the plate cylinder, cleaning mechanism 6 for removing ink adhering to press roller 5, and used And a stencil discharge device 7 for collecting the stencil sheet as a stencil.
For convenience of explanation, the following description will be given with the paper feeder arrangement side as the rear side of the printing apparatus and the paper discharge apparatus arrangement side as the front side of the printing apparatus.

  In FIG. 2, which is an upper perspective view of the press roller portion, the press roller 5 includes a roller shaft 51, a cylindrical roller body 52 that is a rubber layer, and a metal layer 53 formed on the outer periphery of the roller body 52. ing. The roller shaft 51 is rotatably supported by a pair of arm plates 8 arranged at intervals in the paper width direction, and the arm plate 8 is supported by a swing shaft 9 that is rotatably supported by the printing apparatus main body. The press roller 5 swings up and down in accordance with the printing timing by the swing of the swing shaft 9, and comes into contact with the lower end surface of the plate cylinder 4 when it is lifted to hold the paper between the plate cylinder 4 To do. The metal layer 53 is formed by fitting a metal cylinder made by plating on the outer peripheral surface of the press roller 5 or by directly performing plating. Various metals such as aluminum, copper, stainless steel, and nickel can be used for the metal layer 53. The thickness of the metal layer 53 is set to be greater than 20 μm and less than 400 μm, and is preferably set to 50 μm to 310 μm. The surface roughness of the metal layer 53 preferably has a maximum height (Ry value) of 7 μm or less. The hardness of the press roller 5 including the roller main body 52 and the metal layer 53 on the outer peripheral surface thereof is set to 65Hs or more and less than 95Hs, but is preferably set to 65Hs to 85Hs.

  The press roller 5 has an outer diameter of the roller shaft 51 of about 12 mm and a thickness of the roller body 52 of about 10 mm. Although depending on the material of the metal layer 53, when the metal layer 53 is attached to the outer peripheral surface of the press roller 5 having no metal layer 53 by about 50 μm to 310 μm, the hardness of the press roller 5 becomes about 65 Hs to 85 Hs. .

  In FIG. 3, which is an enlarged longitudinal sectional view of FIG. 2, the cleaning mechanism 6 includes a pair of metal blade support plates 61-1 and 61-2 and a urethane rubber made of urethane rubber fixed to the tip of each blade support plate. Mainly composed of blades 62-1 and 62-2. The blade support plates 61-1 and 61-2 are fixed to fixed shafts 63-1 and 63-2 arranged in parallel to the swing shaft 9 and the roller shaft 51 and below the shafts. The leading ends of the blades 62-1 and 62-2 are positioned by the positioning shims 64-1 and 64-2 so as to contact the metal layer 53 of the press roller, and are moved forward and upward toward the front end of the press roller 5. It extends. The front end of the blade 62-1 on the front side extends in a substantially tangential direction in the vicinity of the front end of the press roller 5 so as to be substantially opposite to the rotation direction A of the press roller 5, and the front end contacts the metal layer 53. The ink adhering to the metal layer 53 of the roller 5 is scraped off. The tip of the rear blade 62-2 extends in a substantially tangential direction at a position slightly behind and below the contact portion of the front blade 61-1 so as to be substantially opposite to the rotation direction A of the press roller 5, The tip is in contact with the metal layer 53, and the ink left by the front blade 62-1 is scraped off. The lengths of the blades 62-1 and 62-2 in the axial direction are the same as the length of the press roller 5 in the axial direction.

  In the embodiment, two blades 62-1 and 62-2 are provided, but one blade may be provided, or three or more blades may be provided.

[Operation]
Next, the operation of the printing apparatus having the above configuration will be described.

  In FIG. 1, a stencil sheet made by the plate making apparatus 3 is mounted on the outer peripheral surface of the plate cylinder 4 before starting printing.

  When printing is started, the paper of the paper feeding device 1 is supplied to the timing roller 12 one by one from the top by the paper feeding roller 11, and the timing roller 12 matches the rotation angle of the plate cylinder 4 at a predetermined feeding timing. Then, the sheet is fed into the image forming unit between the plate cylinder 4 and the press roller 5.

  The sheet fed to the image forming unit is pressed against the outer peripheral surface of the plate cylinder 4 by the rising press roller 5, whereby the image of the stencil sheet of the plate cylinder 4 is transferred (printed) on the upper surface of the sheet.

  The printed paper is discharged from the paper discharge device 2 to the paper tray 21.

  While printing is normally performed on the upper surface of the paper, almost no ink adheres to the press roller 5, but even if the paper is not fed from the paper feeding device 1 or the paper is jammed before the image forming unit. The press roller 5 rises and contacts the plate cylinder 4 in accordance with the rotation of the timing roller 12 and the plate cylinder 4, so that the ink may directly adhere to the metal layer 53 on the outer peripheral surface of the press roller 5.

  Further, when printing the back side of the paper on which one side is printed, the printed side comes into contact with the press roller 5, and the ink on the printed side adheres to the metal layer 53 on the outer peripheral surface of the press roller 5. There are things to do.

  When ink adheres to the outer peripheral surface of the press roller 5 in this way, the ink attached to the press roller 5 is scraped off in two stages by the two blades 62-1 and 62-2 while the press roller 5 is rotating. It is done.

  Therefore, even when normal printing is started again, the ink does not adhere to the back surface of the paper from the press roller 5, and the back surface of the paper can be prevented from being stained.

[Effect of the embodiment]
According to the printing apparatus having the above configuration, the following effects can be exhibited.

  The press roller 5 is subjected to printing many times, but ink adhering during printing is scraped off by the blades 62-1 and 62-2. Therefore, it is possible to prevent the adhered ink from being transferred to the paper.

  Since the metal layer 53 is formed on the outer peripheral surface of the press roller 5, it is possible to improve the durability of the press roller 5 during printing and cleaning.

  The thickness of the metal layer 53 is more than 20 μm and less than 400 μm, and the hardness of the press roller 5 including the roller main body 52 and the metal layer 53 on the outer peripheral surface is 65 Hs or more and less than 95 Hs. While adopting a durable metal layer 53 on the outer peripheral surface of the plate, the ink attached to the press roller 5 can be smoothly scraped off by the blades 62-1 and 62-2, and the pressing force of the plate cylinder 4 and the press roller 5 can be removed. High-quality printing can be performed without losing the balance.

  Incidentally, when the thickness of the metal layer 53 is 400 μm or more, the hardness of the press roller 5 is too high, and the print image is deteriorated. Further, when the thickness of the metal layer 53 is 20 μm or less, the metal layer 53 itself is wrinkled or torn, so that the ink adhering to the metal layer 53 cannot be scraped well. It may cause deterioration.

  Since the surface roughness of the metal layer 53 has an Ry value (maximum height) of 7 μm or less, when the ink attached to the metal layer 53 is scraped with the blades 62-1 and 62-2, the blade 62-1, 62-2 can easily come into contact with the metal layer 53, so that the remaining ink is not scraped off.

  In addition, when the hardness of the press roller 5 including the roller main body 52 and the metal layer 53 on the outer peripheral surface thereof is 95 Hs or more, the balance of the pressing force between the press roller 5 and the plate cylinder 4 is lost, and the printing image is deteriorated. It will get worse. Incidentally, the hardness of the press roller 5 that does not have the metal layer 53 is usually about 30 to 35 Hs.

  By configuring the blades 62-1 and 62-2 with urethane rubber, the frictional force between the metal layer 53 of the press roller 5 and the blades 62-1 and 62-2 has an appropriate magnitude. The ink attached to the metal layer 53 can be effectively scraped off while preventing biting of -2.

  Since the cleaning mechanism 6 has the two blades 62-1 and 62-2, the ink that could not be scraped off by the single blade 62-1 can be surely scraped off. Further, by making the widths of the blades 62-1 and 62-2 equal to the axial length of the press roller 5, the ink adhering to the press roller 5 can be removed over the entire length of the press roller 5 without leakage. It becomes possible.

  Since the blades 62-1 and 62-2 that are in contact with the metal layer 53 of the press roller 5 are arranged so that the tips of the blades 62-1 and 62-2 face the rotation direction A of the press roller 5, That is, as shown in FIG. 3, the rear surfaces of the blades 62-1 and 62-2 extending from below are brought into contact with the press roller 5 rotating in the rotation direction A in the vicinity of the front end portion of the press roller 5. The blades 62-1 and 62-2 are brought into contact with the press roller 5 more strongly when the press roller 5 is rotated than when being brought into contact with the vicinity of the rear end of the roller 5. From the viewpoint of contact pressure, the blade 62-1 , 62-2 makes it easier to scrape ink adhering to the press roller 5. Accordingly, ink can be scraped off more effectively.

[Another embodiment]
The printing apparatus according to the embodiment preferably includes a configuration in which the roller shaft 51 of the press roller 5 is connected to a drive mechanism such as a motor, and the press roller 5 is driven at the same peripheral speed as the peripheral speed of the plate cylinder 4.

  When the peripheral speed of the press roller 5 is driven to be the same as the peripheral speed of the plate cylinder 4, it is possible to prevent a print image from being shifted due to a delay in the peripheral speed of the press roller 5 with respect to the plate cylinder 4.

  FIG. 4 shows a modified example of the blades 62-1 and 62-2, where the cross-sections of the tip portions of the blades 62-1 and 62-2 are formed in a single-sided shape with an acute triangle. A slope B is formed on the radially outer side.

  When the blades 62-1 and 62-2 are formed as described above, the blades 62-1 and 62-2 can more easily scrape the ink attached to the press roller 5. Accordingly, ink can be scraped off more effectively.

[Other Embodiments]
FIG. 5 is an example in which the present invention is applied to a stencil duplex printing apparatus having a duplex printing function, and the stencil duplex printing apparatus has a first printing unit 41 and a second printing unit 42 spaced apart in the front-rear direction. The switchback type reversing path 43 comprising a plurality of air suction type belt conveying mechanisms is arranged in the conveying path between the printing units 41 and 42. Except for the structure in which the pair of printing units 41 and 42 and the reverse path 43 are provided, the configuration is the same as in the first embodiment, and the same components are denoted by the same reference numerals.

The operation of the printing apparatus having the above configuration will be described.
The sheets of the sheet feeding device 1 are supplied one by one from the top to the timing roller 12 by the sheet feeding roller 11. The timing roller 12 adjusts the sheet in accordance with the rotation angle of the plate cylinder 4 of the first printing unit 41. The image is sent to the image forming unit of the first printing unit 41.

  The sheet fed to the image forming unit is pressed against the outer peripheral surface of the plate cylinder 4 by the rising press roller 5, whereby the image of the stencil sheet of the plate cylinder 4 is transferred (printed) on the upper surface of the sheet. The printed paper is discharged to the reverse path 43.

  While printing is normally performed on the upper surface of the paper, almost no ink adheres to the press roller 5, but even if the paper is not fed from the paper feeding device 1 or the paper is jammed before the image forming unit. The press roller 5 rises and contacts the plate cylinder 4 in accordance with the rotation of the timing roller 12 and the plate cylinder 4, so that the ink may directly adhere to the metal layer 53 on the outer peripheral surface of the press roller 5.

  When ink adheres to the outer peripheral surface of the press roller 5 in this way, the ink attached to the press roller 5 is scraped off in two stages by the two blades 62-1 and 62-2 while the press roller 5 is rotating. Thus, it is possible to prevent the adhered ink from being transferred to the paper.

  In the reversing path 43, the sheet is turned upside down (front and back) and sent to the image forming unit of the second printing unit 42.

  The sheet fed to the image forming unit of the second printing unit 42 is pressed against the outer peripheral surface of the plate cylinder 4 by the rising press roller 5, whereby the image of the stencil sheet of the plate cylinder 4 is applied to the upper surface of the sheet. Transferred (printed). The printed paper is discharged from the paper discharge device 2 to the paper tray 21.

  In the second printing unit 42, the printing surface of the paper printed by the first printing unit 41 comes into contact with the press roller 5, so that the ink on the printing surface adheres to the metal layer 53 on the outer peripheral surface of the press roller 5. There are things to do.

  When ink adheres to the outer peripheral surface of the press roller 5 in this way, the ink attached to the press roller 5 is scraped off in two stages by the two blades 62-1 and 62-2 while the press roller 5 is rotating. It is done.

According to the printing apparatus having the above configuration, the following effects can be exhibited.
The press roller 5 is subjected to printing many times, but the ink printed by the first printing unit 41 may adhere to the press roller 5 when printing by the second printing unit 42. Although there is ink, the adhered ink is scraped off by the blades 62-1 and 62-2. Therefore, it is possible to prevent the adhered ink from being transferred to the paper.

  In particular, in the case of the above-described double-sided printing apparatus, two printing units of the plate cylinder 4 and the press roller 5 are provided, and one side of the paper printed by the first printing unit 41 is a press roller in the second printing unit 42. Since the ink is likely to be re-transferred to the press roller 5, the application of the present invention to such a double-sided printing apparatus can provide a remarkable effect by cleaning.

  In the above embodiment, the example in which the present invention is applied to the stencil printing apparatus for single-sided printing and the stencil printing apparatus for double-sided printing has been shown, but the present invention is applied to all stencil printing apparatuses such as stencil printing apparatuses for multicolor printing. The invention can be applied. Further, the present invention can be applied to a printing apparatus other than a stencil as long as the printing apparatus includes a printing unit that transfers an ink image to a printing medium based on a stencil sheet.

  Since the present invention is a printing apparatus that is excellent in durability and prevents high quality printing by removing ink adhering to a press roller and preventing transfer to paper, the industrial utility value is It ’s big.

It is a schematic side view of a stencil printing apparatus. It is an upper perspective view of a press roller part. It is a longitudinal cross-sectional enlarged view of FIG. It is a cross-sectional enlarged view similar to FIG. 3 which shows the modification of a blade. It is a schematic side view of other embodiment of the stencil printing apparatus by this invention.

DESCRIPTION OF SYMBOLS 1 Paper feeder 2 Paper discharge device 3 Plate making device 4 Plate cylinder 5 Press roller 6 Cleaning mechanism 7 Plate discharge device 8 Arm plate 9 Oscillating shaft 51 Roller shaft 52 Roller body 53 Metal layer 61-1 Blade support plate 61-2 Blade support Plate 62-1 Blade 62-2 Blade 63-1 Fixed shaft 63-2 Fixed shaft 64-1 Positioning shim 64-2 Positioning shim

Claims (5)

In a printing apparatus that prints by pressing a sheet against a plate cylinder by a press roller,
Equipped with a cleaning mechanism to clean the press roller,
The press roller has a roller shaft, a roller body that is a rubber layer provided on the outer periphery of the roller shaft, and a metal layer formed on the outer periphery of the roller body ,
The cleaning mechanism has a blade for scraping off ink adhering to the metal layer;
The surface roughness of the metal layer has an Ry value of 7 μm or less .   The printing apparatus according to claim 1, wherein the thickness of the metal layer is more than 20 μm and less than 400 μm.   The printing apparatus according to claim 1 or 2, wherein the hardness of all the press rollers including the press roller and the metal layer on the outer peripheral surface is 65Hs or more and less than 95Hs. The printing apparatus according to claim 1 , wherein the press roller is driven by a drive mechanism so that a peripheral speed of the press roller is equal to a peripheral speed of the plate cylinder. The printing apparatus according to claim 1 , having a double-sided printing function.

Images