JP2010194727A - Dryer for printing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing machine which can certainly harden a print by drying while preventing the object from coming into contact with a dryer due to the flapping of the print. <P>SOLUTION: The dryer T for a printing machine includes ultraviolet irradiation parts 22, 23 and 24 which are so constituted that they can ascend the surface of a drying barrel 11. In addition, a holder 22 with a rack 22b to be engaged with a pinion 26 fixed to a shaft 25, is actuated vertically by rotation of a motor M. Besides, the position of the ultraviolet irradiation parts 22, 23 and 24 to the drying barrel 11, is decided in compliance with the state of a sheet P to be used. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a printer provided with a drying device using a light emitting diode, which is provided to dry an ultraviolet curable paint on a printing paper. In the present invention, the “paint” includes not only ink but also varnish used for surface protection and gloss of printed matter after printing with ink.

  In recent years, drying apparatuses using light emitting diodes that irradiate ultraviolet rays have been used as drying apparatuses for printing presses. Conventional drying equipment using a high-pressure mercury lamp or xenon lamp as a light source has a concern about adverse effects on the printed material due to heat generation. However, a drying device using a light-emitting diode as a light source generates less heat, so deformation of the printed material. There is an advantage that there is no fear of distortion. Patent Document 1 discloses a drying device for a printing press using a light emitting diode.

  On the other hand, a drying device using a light emitting diode needs to efficiently dry and cure a printed material passing at high speed, and it is necessary to reduce the distance from the printed material as much as possible.

JP 2008-207369 A

  Generally, in this type of printing machine, a sheet of paper to be printed is transported with the leading end in the transport direction being sandwiched between claws provided on the cylinder. As a result, the trailing edge of the sheet flutters and jumps up during transportation, and may come into contact with the drying device, causing the sheet to become dirty or scratched. Ink may also adhere to the drying device. was there. On the other hand, if the distance of the drying device is increased with respect to the sheet to prevent contact, there is a possibility of poor drying, and there is room for improvement.

  In view of the above-described problems, the present invention can reliably dry and cure a printed material while preventing contact with the drying device due to fluttering of the printed material in a printing machine equipped with a drying device using a light emitting diode. It is an object of the present invention to provide a printing press that can be used.

  The present invention provides a printing unit B for printing an image on a conveyed sheet P using an ultraviolet curable paint, and the ultraviolet curable type of the sheet P printed and conveyed by the printing unit B. In a printing machine provided with a drying device T having ultraviolet irradiation units 22, 23, 24 for drying and curing paint on the drying cylinder 11 by irradiation of a light emitting diode 24, the ultraviolet irradiation units 22, 23, 24 are provided. The drying cylinder 11 is provided so as to be able to contact and separate.

  Since the drying device in the printing press of the present invention is provided with the ultraviolet irradiation section so as to be able to come into contact with and separate from the drying cylinder, it is possible to prevent the contact between the sheet and the drying device, while the sheet used is used. There is an advantage that the light emitting diode can be irradiated at an optimum distance, and the UV-type curable paint on the sheet can be efficiently and surely dried and cured.

Schematic side view of a sheet-fed offset printing press equipped with a drying device according to the present invention Front view of main parts of drying device T Schematic block diagram showing the control unit of the drying device of the printing press according to the present invention Table showing the distance between the UV irradiation section and the drying cylinder for the paper thickness

  A printing press according to an embodiment of the present invention will be described with reference to FIGS. As shown in the schematic overall view of FIG. 1, the printing press according to this embodiment is a sheet-fed offset printing press. The printing machine includes a sheet feeding unit A for sending out sheets P as printing sheets one by one from a sheet stacking unit by a feeder device, a sheet separating device, and the like, and a sheet P from the sheet feeding unit A. A printing unit B for printing and a paper discharge unit C for discharging the sheet P are provided. Here, the printing unit B is a printing unit B including five printing units 5 so that five colors can be printed. However, the printing unit can print colors other than five colors, that is, one color or two or more colors. It may be. Further, although the paper discharge unit C is constituted by the chain conveying device 12 having a gripper, the paper discharge unit C may be a printing machine without the paper discharge unit C, or the specifics of each part constituting the printing machine. The specific configuration is not limited to that shown in the figure.

  The printing unit 5 includes a plate cylinder 1, a rubber cylinder 2, an ink roller group 4, an impression cylinder 3, and a transfer cylinder 6. The ink roller group 4 supplies ink that is an ultraviolet curable paint. Although not shown, each of the cylinders 3 and 6 has two grippers (one or three or more in the circumferential direction) for gripping the fed sheet P with the claw base and the claw. ) Reference numeral 7 denotes a paper feed cylinder which plays a role of receiving the sheet P conveyed on the feeder board 8 and the mouth plate 9 from the swing arm 10 and transferring it to the impression cylinder 3. The feeding cylinder 7 and the swing arm 10 are also provided with the claw base and the claw.

  A drying device T according to the present invention is provided between the final printing unit 5 of the printing unit and the paper discharge unit C. That is, the sheet P conveyed by the impression cylinder 3 of the final printing unit 5 is transferred to the transfer cylinder 6 and further transferred to the drying cylinder 11. A drying device T is provided on the upper portion of the drying cylinder 11.

  As shown in FIG. 2, the drying device T includes a large number of light emitting diodes 24 having irradiation axes in a direction substantially orthogonal to the surface of the drying drum 11, and the light emitting diodes 24 are disposed above the drying drum 11. ing. A large number of these light-emitting diodes 24 are provided on the substrate 23 and are arranged in the width direction of the sheet P (drying cylinder 11). Specifically, 44 light emitting diodes 24 are arranged on a straight line at a predetermined interval, but one light emitting diode 24 is provided on one substrate 23, and this substrate 23 is made of a sheet of paper. Four units are connected in the width direction. The ultraviolet curable paint on the sheet P is cured by the ultraviolet irradiation of the light emitting diode 24. The substrate 23, the light emitting diode 24, and a holder 22 described later constitute an ultraviolet irradiation unit.

  Guide rails 21 and 21 are fixed to left and right frames of a printing press (not shown), respectively. Holders 22 and 22 are engaged with the guide rails 21 and 21 so as to be movable up and down, respectively. The portion of the holder 22 that engages with the guide rail 21 is an LM guide. The holder 22 has a substantially L shape, and the substrate 23 provided with the light emitting diode 24 is placed thereon. Therefore, the light emitting diode 24 can move up and down together with the holder 22.

  A shaft 25 is suspended between the left and right frames of the printing press, and can be rotated by a motor M fixed to the frame at one end of the shaft 25. Pinions 26 are fixed to the left and right portions of the shaft 25. On the other hand, a rack 22a is formed on one side surface of the holder 22, and the rack 22a and the pinion 26 are engaged with each other. Therefore, by rotating the shaft 25 and the pinion 26 by the motor M, the holder 22 having the rack 22 a meshed with the pinion 26 moves up and down with the substrate 23 and the light emitting diode 24. Since the left and right holders 22 and 22 are moved up and down by the same shaft 25, there is no displacement in the vertical direction of the left and right holders 22 and 22 when ascending and descending, and the holder 22, that is, the light emitting diode 24 is moved up and down accurately. Can be made. The left and right holders 22 and 22 may be moved up and down by separate driving.

  Detection pieces 22b are provided at the left and right lower ends of the holder 22 in FIG. On the other hand, an upper limit detection sensor 27, an intermediate position detection sensor 28, and a lower limit detection sensor 29 are fixed to the guide rail 21 from the upper side to the lower side. Each of the sensors 27 to 29 is a proximity sensor, and is configured to detect passage of the detection piece 22b.

  FIG. 3 is a schematic block diagram showing the control unit of the drying device of the printing press according to the embodiment of the present invention. The upper limit detection sensor 27, the intermediate position detection sensor 28, the lower limit detection sensor 29, the motor M, and the touch panel type. In addition, various operations of the printing press are possible, and the monitor 51 and the control unit 50 notify the operator of various statuses of the printing press. The control unit 50 includes a microprocessor 50a (which may be a sequencer) that performs arithmetic processing, a ROM 50b that stores data and a predetermined program (such as an arithmetic expression or a table), a RAM 50c that can store various information relating to the machine speed, a micro It is configured using an interface 50d that mediates exchange of various signals between the processor 50a and a device provided outside the control unit 50.

  Next, the operation of the drying device of the printing press according to the embodiment of the present invention will be described. In the printing operation, the operator performs various inputs via the monitor 51. At that time, the sheet thickness is also input. The motor M moves up and down according to an instruction from the control unit 50 based on the input sheet thickness, and the motor M stops when the sensors 27 to 29 detect the detection piece 22b of the holder 22. Specifically, the control is performed as shown in the table of FIG. That is, when the input paper thickness is less than 0.2 mm, the motor M is driven so that the distance between the surface of the drying cylinder 11 and the light emitting diode 24 of the ultraviolet irradiation section becomes 10 mm, and the lower limit detection sensor 29 detects the detection piece 22b. Is detected, the motor M is controlled to stop. Similarly, when the input sheet thickness is 0.2 mm or more and less than 0.4 mm, the motor M is driven so that the distance becomes 15 mm, and the motor M stops when the intermediate position detection sensor 28 detects the detection piece 22b. It is controlled as follows. When the input paper thickness is 0.4 mm or more, the motor M is driven so that the distance becomes 25 mm, and the motor M is controlled to stop when the upper limit detection sensor 27 detects the detection piece 22b. As the paper thickness increases, the paper fluttering tends to increase, so that the ultraviolet irradiation section is spaced apart as the paper thickness increases.

  In the present embodiment, the vertical position of the ultraviolet irradiation unit is determined according to the thickness of the paper, but the present invention is not limited to this. Depending on the type of paper, the upper and lower positions of the ultraviolet irradiation section may be determined, or the upper and lower positions may be determined according to the type of ink used, the number of printing units, and the presence or absence of varnish coating, These may be combined. Further, the ultraviolet irradiation unit may be moved up and down according to the printing speed. In this case, as the speed increases, the flutter increases in an accelerated manner. Therefore, it is better to separate the ultraviolet irradiation portions more as the speed increases. That is, it is a feature of the present invention that it is controlled so as to determine the optimum vertical position of the ultraviolet irradiation unit according to the state of the used sheet (thickness, rigidity, wetness, conveyance state, etc.). .

  The drying apparatus of the printing press according to the present invention is not limited to the above-described embodiment, and various modifications and improvements can be made within the scope described in the claims. For example, in the above-described embodiment, the light emitting diode 24 and the substrate 23 that are the ultraviolet irradiation unit, and the holder 22 that holds them are moved up and down by driving the motor M and automatically stopped by the sensors 27 to 29. 22 may be manually moved up and down to a desired position. Moreover, it is a type which performs varnish coating with a varnish unit after printing by a printing unit, and this varnish may be an ultraviolet curable type. In the above-described embodiment, the sheet-fed offset printing machine is used. However, the present invention is not limited to this, and a rotary paper offset printing machine, an ink jet printing machine, or a flexographic printing machine may be used.

  The printer according to the present invention is extremely useful in a printer having a drying device.

DESCRIPTION OF SYMBOLS 11 Drying cylinder 21 Guide rail 22 Holder 22a Rack 22b Detection piece 23 Substrate 24 Light emitting diode 25 Axis 26 Pinion 27 Upper limit detection sensor 28 Intermediate position detection sensor 29 Lower limit detection sensor 50 Control part 51 Monitor M Motor T Drying device

Claims (1)

  A printing unit for printing an image on the conveyed sheet using an ultraviolet curable paint, and the ultraviolet curable paint of the sheet printed and conveyed by the printing unit is emitted on a drying cylinder. A printing machine comprising a drying device having an ultraviolet irradiation unit for drying and curing by irradiation of a diode, wherein the ultraviolet irradiation unit is brought into contact with and separated from the drying cylinder. apparatus.

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