JP2007015183A - Stencil printing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stencil printing apparatus in which troubles such as paper jams do not occur and wasteful stencil paper is not used when printing is performed by only a part of a plurality of printing units.
SOLUTION: Drums 25 and 36 having outer peripheral walls 25a and 36a formed of an ink impermeable member, ink supply means for supplying ink to the surfaces of the outer peripheral walls 25a and 36a, and pressing the outer peripheral walls 25a and 36a. The apparatus includes a plurality of printing units 4 and 6 having press rolls 27 and 38, and each of the printing units 4 and 6 includes cleaning means 90 and 95 for removing ink adhering to the surface of the outer peripheral wall 25a. When printing is performed, the surfaces of the outer peripheral walls 25a and 36a of the printing portion where printing is not performed are cleaned by the cleaning means 90 and 95, and the stencil sheet 12 is not wound around the outer peripheral walls 25a and 36a, and ink is supplied from the ink supply means. Instead, the printing paper 20 is transported between the rotating outer peripheral walls 25a and 36a and the press rolls 27 and 38 positioned at the pressing position.
[Selection] Figure 1

Description

  The present invention relates to a stencil printing apparatus including a plurality of printing units each having a drum and a press roll, and capable of performing color printing, for example.

  In this type of conventional stencil printing apparatus, the outer peripheral wall provided rotatably is formed of an ink permeable member, the drum on which the stencil paper is mounted on the surface of the outer peripheral wall, and the surface of the outer peripheral wall from the inside of the drum There are two printing units between the paper supply unit and the paper discharge unit, each having an ink supply unit that supplies ink to the printer and a press roll that moves between a pressing position that presses the outer peripheral wall and a separating position that separates the outer peripheral wall. .

  A stencil sheet punched for the first color is mounted on the drum of the first printing section, and a stencil sheet punched for the second color is mounted on the drum of the second printing section. Then, the printing paper is sequentially conveyed to the first and second printing units, and each printing unit conveys the printing paper between the rotating outer peripheral wall and the press roll positioned at the pressing position. Are transferred onto the printing paper from the perforations of the stencil sheet, thereby obtaining a two-color printed matter.

  By the way, in such a stencil printing apparatus, there is a method of performing monochromatic printing using only one of the printing units. In monochromatic printing, it is necessary to prevent ink transfer when the printing paper passes through a printing section where printing is not performed. As a method therefor, a method has been proposed in which the drum of the non-printing section is stopped and the press roll is transported without applying printing pressure to the printing paper (see, for example, Patent Document 1).

In addition, a method has also been proposed in which a non-perforated stencil sheet is wound around a drum in a non-printing section and transported so that ink is not transferred to the printing paper using a press roll as a pressing position (see, for example, Patent Document 2).
JP 2000-326614 A JP 2001-315422 A

  However, in the former case, when the printing paper is conveyed through the printing unit where printing is not performed, the conveyance force is not applied from the drum and the press roll. There is a high possibility of trouble.

  In the latter case, since the printing paper is conveyed while being nipped between the drum and the press roll, troubles such as paper jam do not occur. However, since the stencil paper without perforation is wound around the drum, One sheet of wasted paper is wasted. Such a situation similarly occurs when there are three or more drums and printing is performed with a printing color smaller than the number of drums.

  By the way, the present applicant has an outer peripheral wall that is rotatable and formed of an ink impermeable member, a drum on which a stencil sheet is mounted on the surface of the outer peripheral wall, and the outer peripheral wall of the drum. A stencil printing apparatus including an ink supply unit that supplies ink to the surface and a press roll that presses a fed printing medium against an outer peripheral wall has been proposed (see, for example, Japanese Patent Application Laid-Open No. 2004-122712). In this stencil printing apparatus, when the outer peripheral wall of the drum is rotated and the surface of the outer peripheral wall is supplied with ink from the ink supply means, and the printing medium is fed, the printing medium is turned into a press roll. The stencil sheet is conveyed while being pressed against the outer peripheral wall of the stencil sheet and the drum, while the ink between the outer peripheral wall of the drum and the stencil sheet is diffused downstream in the printing direction while being pressed by the pressing force of the press roll. The diffused ink oozes out from the perforations of the stencil sheet and is transferred to the print medium side, and an ink image is printed on the print medium.

  The above-described two-color stencil printing apparatus can be manufactured using a drum having an outer peripheral wall formed of such an ink impermeable member. In the stencil printing apparatus having such a structure, since the outer peripheral wall is an ink impermeable member, the ink supplied to the surface of the outer peripheral wall does not enter the outer peripheral wall. Easy to do.

  That is, in the printing unit that does not perform printing, the stencil sheet used for the previous printing is wound around the outer peripheral wall as it is, but ink is not supplied to the outer peripheral wall from the ink supply means during printing. And a printing paper is conveyed in the state which pressed the press roll to the outer peripheral wall with the press pressure weaker than the time of normal printing. In this way, in the printing unit that does not perform printing, the printing paper is reliably and stably conveyed while being nipped between the outer peripheral wall and the press roll, so that troubles such as paper jams do not occur. Further, since an unperforated stencil sheet is not wound around the outer peripheral wall, there is no need to use a useless stencil sheet.

  However, even in an apparatus using a drum of an ink impermeable member, there is some residual ink between the outer peripheral wall and the stencil sheet after normal printing. Accordingly, if the printing paper is transported between the outer peripheral wall and the press roll in a state where the press pressure is applied even if it is weak, there is a possibility that ink stains will occur on the printing paper.

  SUMMARY OF THE INVENTION Accordingly, the present invention provides a stencil printing apparatus that does not cause trouble such as a paper jam when printing is performed only in a part of a plurality of printing units, and that does not use waste stencil paper. With the goal.

  The invention according to claim 1, which achieves the above object, has a drum in which an outer peripheral wall provided rotatably is formed of an ink impermeable member, and a stencil sheet is mounted on a surface of the outer peripheral wall, and an outer peripheral wall of the drum A plurality of printing units each including an ink supply unit that supplies ink to the surface of the sheet, and a press roll that moves between a pressing position that presses the outer peripheral wall and a separating position that separates the outer peripheral wall, and a printing medium is provided in the plurality of printing units. In each of these printing sections, the printing medium is transported between the rotating outer peripheral wall and the press roll positioned at the pressing position, and is supplied to the outer peripheral wall from the ink supply means in this transport process. In the stencil printing apparatus for printing by transferring ink from the stencil sheet to the printing medium, each printing unit removes ink adhering to the surface of the outer peripheral wall. When the printing unit has printing means and performs printing only in a part of the plurality of printing units, the printing unit that does not perform printing cleans the surface of the outer peripheral wall by the cleaning unit, and the cleaned outer periphery. The printing medium is transported between the rotating outer peripheral wall and the press roll positioned at the pressing position without winding stencil paper around the wall and without supplying ink from the ink supply means to the outer peripheral wall. It is characterized by that.

  A second aspect of the present invention is the stencil printing apparatus according to the first aspect, wherein the cleaning unit is in contact with the outer peripheral wall by driving a driving source and driving the driving source to scrape the remaining ink. And an ink scraping member that shifts between a standby position separated from the surface of the outer peripheral wall.

  A third aspect of the present invention is the stencil printing apparatus according to the second aspect, wherein the ink scraping member is a blade.

  A fourth aspect of the present invention is the stencil printing apparatus according to any one of the first to third aspects, wherein the ink recovery port has an ink recovery port at a position downstream of the maximum printing area of the outer peripheral wall. Ink recovery means for recovering the ink flowing in is provided.

  A fifth aspect of the present invention is the stencil printing apparatus according to the first or fourth aspect, wherein the cleaning means abuts against the outer peripheral wall by driving a driving source and the driving source to wipe off residual ink. An ink wiping member that changes between a position and a standby position that is separated from the surface of the outer peripheral wall is provided.

  A sixth aspect of the present invention is the stencil printing apparatus according to the fifth aspect, wherein the ink wiping member is a cleaning cloth.

  A seventh aspect of the present invention is the stencil printing apparatus according to the fifth aspect, wherein the ink wiping member is a cleaning roll.

  According to the first aspect of the present invention, the ink remaining on the outer peripheral wall after removing the stencil sheet is easily and cleanly removed by cleaning the cleaning means because the outer peripheral wall is an ink impermeable member. A print medium conveyed through a printing unit that does not perform printing passes without being smudged with ink even if conveyed while being pressed against an outer peripheral wall by a press roll, and a printed matter printed only by the printing unit that performs printing can be obtained. it can. In the printing unit that does not perform printing, the print medium is reliably and stably conveyed while being nipped between the outer peripheral wall and the press roll, and the stencil sheet is not wound around the outer peripheral wall. As described above, when printing is performed only in a part of the plurality of printing sections, trouble such as paper jam does not occur, and wasteful stencil paper is not used.

  According to the invention of claim 2, when the outer peripheral wall is rotated in a state where the ink scraping member is positioned at the ink scraping position, the ink scraping member moves while scraping the remaining ink on the surface of the outer peripheral wall. Residual ink on the entire wall can be removed. In addition, since the ink scraping member can be positioned at the standby position except during cleaning, it is possible to prevent the cleaning unit from hindering other operations such as a printing operation.

  According to the third aspect of the present invention, the remaining ink can be scraped off strongly and without damage.

  According to the invention of claim 4, since the residual ink scraped off by the ink scraping member can be recovered from the ink recovery port, wasteful ink consumption can be suppressed.

  According to the invention of claim 5, when the outer peripheral wall is rotated in a state where the ink wiping member is positioned at the cleaning position, the ink wiping member moves while wiping off the remaining ink on the surface of the outer peripheral wall, so that the remaining area of the entire outer peripheral wall remains. Ink can be removed. In addition, since the ink wiping member can be positioned at the standby position except during cleaning, it is possible to prevent the cleaning unit from hindering other operations such as a printing operation.

  According to the invention of claim 6, the remaining ink can be removed without causing any damage to the outer peripheral wall.

  According to the invention of claim 7, the remaining ink can be removed without causing any damage to the outer peripheral wall.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  1 to 5 show an embodiment of the present invention, FIG. 1 is a schematic configuration diagram of a stencil printing apparatus, FIG. 2 is a perspective view of a first drum, and FIG. 3 is a cross-sectional view taken along line AA in FIG. 4 is a cross-sectional view taken along the line BB in FIG. 2, and FIG. 5 is a flowchart at the time of monochromatic printing.

  In FIG. 1, a stencil printing apparatus 1 includes an original reading unit (not shown), a plate making unit 2, a paper feeding unit 3, a first printing unit 4, an intermediate transport unit 5, and a second printing unit 6. The paper discharge unit 7 is mainly composed of a first plate discharge unit 8 and a second plate discharge unit 9.

  The document reading unit is provided on the upper portion of the apparatus body 10 and reads a document to be printed as image data. The read image data is generated as plate making data for the color ink of the first drum 25 and the color ink of the second drum 36. The plate making data can be processed based on a predetermined command (enlargement, reduction, etc.).

  The plate making unit 2 includes a plate making unit 11 provided in the apparatus main body 10 so as to be horizontally movable. The plate making unit 11 supplies a stencil sheet 12 to a first drum by a plate making unit moving means (not shown). It is moved between the base paper supply position (the phantom line position in FIG. 1) and the second base paper supply position (the solid line position in FIG. 1) for supplying the stencil paper 12 to the second drum. The stencil unit 11 includes a base paper storage unit 13 for storing the rolled long stencil base paper 12, a plurality of transport rolls 14 for guiding the stencil base paper 12 stored in the base paper storage unit 13 to the transport downstream side, and these A thermal head 15 disposed on the downstream side of the conveyance roll 14, a platen roll 16 disposed at a position opposed to the thermal head 15 and rotated by a driving force of a light pulse motor (not shown), a platen roll 16, A pair of base paper feed rolls 17, 17 which are arranged on the downstream side of the stencil sheet 12 with respect to the thermal head 15 and are rotated by the driving force of the light pulse motor, the pair of base paper feed rolls 17, 17 and the platen roll 16, And a base paper cutter 18 disposed between the thermal head 15 and the thermal head 15.

  The paper feed unit 3 includes a paper feed base 21 on which print papers 20 as print media are stacked, primary paper feed rolls 22 and 23 that transport only the uppermost print paper 20 from the paper feed base 21, and A pair of secondary paper feed rolls 24 that feed the printing paper 20 moved by the primary paper feed rolls 22 and 23 between the first drum 25 and the first press roll 27 in synchronization with the rotation of the first drum 25 described later. , 24. The rotation of a main motor (not shown) is selectively transmitted to the primary paper feed rolls 22 and 23 and the pair of secondary paper feed rolls 24 and 24 via respective paper feed clutches (not shown). It is configured.

  Further, the paper feed unit 3 includes a paper sensor S1 having a paper conveyance path between the primary paper feed rolls 22 and 23 and the secondary paper feed rolls 24 and 24 as a detection point, secondary paper feed rolls 24 and 24, A secondary paper feed sensor S2 having a paper conveyance path between one drum 25 as a detection point is provided. The paper sensor S1 detects whether or not the printing paper 20 is conveyed from the primary paper feeding rolls 22 and 23 within a predetermined allowable timing. The secondary paper feed sensor S2 detects whether the printing paper 20 is conveyed from the secondary paper feed rolls 24, 24 within a predetermined allowable timing.

  The first printing unit 4 includes a first drum 25 whose outer peripheral wall 25a is rotated in the direction of arrow A in FIG. 1 by the driving force of the main motor, and an outer peripheral wall 25a of the first drum 25. , A first press roll 27 disposed below the first drum 25, a first ink supply means 54 for supplying ink to the surface of the outer peripheral wall 25a of the first drum 25, A first ink collecting unit 73 that collects excess ink on the surface of the first drum 25 and a first cleaning unit 90 that removes ink adhering to the surface of the outer peripheral wall 25a are provided.

  The first press roll 27 is between a pressing position where the first press roll 27 is pressed against the outer peripheral wall 25a of the first drum 25 by a driving force of a solenoid device (not shown) and a spaced position where the first press roll 27 is separated from the outer peripheral wall 15a of the first drum 25. It is configured to be translatable. The first press roll 27 is always positioned at the pressing position during the printing mode period (including trial printing), and is positioned at the separated position during the period other than the printing mode.

  Further, the first printing unit 4 includes a separation claw 28 and a separation nozzle 29 that are disposed in the vicinity of the first drum 25 on the downstream side of the sheet conveyance. The separation claw 28 is inserted between the outer peripheral surface of the first drum 25 and the front end of the printing paper 20 that is conveyed while being attached thereto. As a result, the printing paper 20 that is stuck to the outer peripheral surface of the first drum 25 and is about to rotate is forcibly peeled off from the outer peripheral surface of the first drum 25. An air nozzle (not shown) is provided at the tip of the separation claw 28, and the tip separation air is discharged from the air nozzle at the timing when the printing paper 20 is peeled off. As a result, the leading edge of the printing paper 20 attached to the outer peripheral surface of the first drum 25 is peeled off by the compressed leading edge separation air. The separation air generated by the separation fan 30 is blown from the separation nozzle 29 between the outer peripheral surface of the first drum 25 and the printing paper 20 conveyed in a state of being attached to the first drum 25, and the separation air causes the first separation air to be generated. The printing paper 20 that is stuck to the outer peripheral surface of the first drum 25 and is about to rotate is forcibly separated from the outer peripheral surface of the first drum 25.

  Then, the first printing unit 4 clamps the tip of the stencil sheet 12 conveyed from the plate making unit 2 with the clamp unit 26, and rotates the first drum 25 in this clamped state so that the stencil sheet 12 is moved to the first drum 25. The printing paper 20 is wound around the outer peripheral wall 25a and pressed against the stencil paper 12 of the first drum 25 by the first press roll 27 with the printing paper 20 conveyed in synchronization with the rotation of the first drum 25. Ink is transferred from the perforated portion of the stencil sheet 12 to print an image of the first color.

  The intermediate conveying unit 5 includes a pair of belt-hanging pulleys 31 and 31 disposed at a sheet conveying downstream position of the first drum 25 and a sheet conveying upstream position of a second drum 36 described later, and the pair of belt-hanging pulleys 31. , 31, an infinite end belt 32, a suction fan 33 for sucking the printing paper 20 onto the paper transport surface of the infinite end belt 32, and a belt driving means (not shown) for moving the infinite end belt 32. I have. The intermediate conveyance unit 5 receives the printing paper 20 peeled from the first drum 25 and feeds the received printing paper 20 between the second drum 36 and the second press roll 38 in synchronization with the rotation of the second drum. It is supposed to be.

  Further, the intermediate transport unit 5 is provided with an intermediate sensor S3. The intermediate sensor S3 detects whether or not the printing paper 20 is separated from the first printing unit 4 within a predetermined allowable timing.

  The second printing unit 6 has the same configuration as the first printing unit 4, and the second drum 36 whose outer peripheral wall 36 a rotates in the direction of arrow B in FIG. 1 by the driving force of the main motor (not shown), A base paper clamping portion 37 that is provided on the outer peripheral wall 36 a of the two drums 36 and clamps the leading end of the stencil base paper 12; a second press roll 38 that is disposed below the second drum 36; A second ink supply means (not shown) for supplying ink to the surface of 36a; a second ink recovery means (not shown) for collecting excess ink on the surface of the second drum 36; and a surface of the outer peripheral wall 36a. And a second cleaning means 95 for removing ink adhering to the ink. In addition, the structure of the 2nd press roll 38 is the same as that of the 1st press roll 27, and abbreviate | omits description.

  The second printing unit 6 includes a separation claw 39 and a separation nozzle 40 that are disposed in the vicinity of the second drum 36 on the downstream side of the sheet conveyance. The separation claw 39 is inserted between the outer peripheral surface of the second drum 36 and the front end of the printing paper 20 that is conveyed while being attached thereto. As a result, the printing paper 20 that is stuck to the outer peripheral surface of the second drum 36 and is about to rotate is forcibly peeled off from the outer peripheral surface of the second drum 36. An air nozzle (not shown) is provided at the front end of the separation claw 39, and compressed front end separation air is discharged from the air nozzle at the timing when the printing paper 20 is peeled off. As a result, the leading edge of the printing paper 20 attached to the outer peripheral surface of the second drum 36 is peeled off by the compressed leading edge separation air. The separation air generated by the separation fan 41 is blown from the separation nozzle 40 between the outer peripheral surface of the second drum 36 and the printing paper 20 conveyed in a state of being attached to the outer surface of the second drum 36. The printing paper 20 which is stuck to the outer peripheral surface of the two drums 36 and is about to rotate is forcibly separated from the outer peripheral surface of the second drum 36.

  Then, the second printing unit 6 clamps the tip of the stencil sheet 12 conveyed from the plate making unit 2 with the clamp unit 37, and rotates the second drum 36 in this clamped state so that the stencil sheet 12 is moved to the second drum 36. The printing paper 20 is wound around the outer peripheral wall 36a and is conveyed in synchronization with the rotation of the second drum 36 by pressing the printing paper 20 against the stencil sheet 12 of the second drum 36 by the second press roll 38. Ink is transferred from the perforated portion of the stencil sheet 12 to print a second color image.

  The paper discharge unit 7 includes a belt conveyance mechanism 42 that conveys the printing paper 20 that has been peeled off from the second drum 36, and a paper discharge tray 43 on which the printing paper 20 that has been discharged from the belt conveyance mechanism 42 is placed. . The belt transport mechanism 42 includes a pair of pulleys 42a and 42a, an infinite end belt 42b hung between the pair of pulleys 42a and 42a, and a suction fan that sucks the printing paper 20 onto the paper transport surface of the infinite end belt 42b. 42c and a belt driving means (not shown) for moving the endless belt 42b, the printing paper 20 separated from the second drum 36 is transported to the paper discharge tray 43 and placed on the paper discharge tray 43. It is supposed to be placed. The belt transport mechanism 42 is provided with a paper discharge sensor S4. The paper discharge sensor S4 detects whether or not the printing paper 20 is discharged from the second printing unit 6 within a predetermined allowable timing.

  The first stencil unit 8 has a pair of stencil rolls 44 that convey the stencil sheet 12 that has been unclamped from the first drum 25 while the tip of the stencil sheet 12 wound around the first drum 25 is released from the clamp. , 44 and a plate discharge box 45 for storing the stencil sheet 12 conveyed by the pair of plate discharge rolls 44, 44.

  The second stencil unit 9 has a pair of stencil rolls 46 that conveys the stencil sheet 12 that is unclamped from the second drum 36 while the tip of the stencil sheet 12 wound around the second drum 36 is released from the clamp. , 46 and a plate discharging box 47 for storing the stencil sheet 12 conveyed by the pair of plate discharging rolls 46, 46.

  Next, the configuration of the first drum 25, the base paper clamp unit 26, the first ink supply unit 54, and the first ink collection unit 73 will be described.

  As shown in FIGS. 2 to 4, the first drum 25 includes a support shaft 50 fixed to the apparatus main body 10, and a pair of side disks that are rotatably supported by the support shaft 50 via bearings 51. 52 and a cylindrical outer peripheral wall 53 fixed between the pair of side disks 52 and 52. The outer peripheral wall 53 is integrally driven with a pair of side disks 52, 52 and is driven to rotate by the rotational force of a main motor (not shown). The outer peripheral wall 25a is formed of an ink impermeable member that has rigidity and does not allow ink to pass through. Further, the outer peripheral surface of the outer peripheral wall 25a is subjected to a fluororesin coating process such as a Teflon (registered trademark) process to form a cylindrical surface having no unevenness.

  The base paper clamp portion 26 is provided by using a clamp recess 53a formed along the axial direction of the support shaft 50 of the outer peripheral wall 25a. One end side of the base paper clamp portion 26 is rotatably supported by the outer peripheral wall 25a and protrudes from the outer peripheral wall 25a in the clamp release state indicated by the phantom line in FIG. 4, but the outer peripheral wall in the clamp state indicated by the solid line in FIG. It is provided so as not to protrude from 25a. Therefore, the stencil sheet 26 can clamp the stencil sheet 12 without protruding onto the outer peripheral wall 25a.

  The outer peripheral wall 25a is rotated in the direction of arrow A in FIGS. 2 and 4, and a position slightly rotated from the base paper clamp portion 26 is set as a printing start point. Therefore, the rotation direction A becomes the printing direction M, and the area below the printing start point is the printing area. In the first embodiment, the maximum print area is set to an area capable of A3 size printing. An ink supply port 55 of the first ink supply means 54 is provided upstream of the maximum print area of the outer peripheral wall 25a in the printing direction M.

  As shown in FIGS. 2 to 4, the first ink supply means 54 is sucked by an ink container 57 in which ink is stored, an ink pump 58 that sucks ink in the ink container 57, and the ink pump 58. A first pipe 59 for supplying the ink, and a support shaft 50 to which the other end of the first pipe 59 is connected, an ink passage 60 is formed therein, and a hole 61 is formed at a position opposed to 180 degrees; A rotary joint 63 that is rotatably supported on the outer peripheral side of the support shaft 50 and has a communication hole 62 that can communicate with the hole 61, one end connected to the rotary joint 63, and the other end guided to the outer peripheral wall 53. The second pipe 64 is connected to the other end of the second pipe 64, and the ink supply port 55 is opened on the surface of the outer peripheral wall 53.

  The ink supply port 55 is formed by using an ink supply recess formed along the printing orthogonal direction N of the outer peripheral wall 53 and an ink distribution member 68 disposed inside the recess.

  As shown in FIGS. 2 to 4, the first ink collecting means 73 has an ink collecting port 72 that is opened downstream from the maximum printing area of the outer peripheral wall 53, and one end connected to the ink collecting port 72. The third pipe 74 is connected to the other end of the third pipe 74, and a rotary joint 63 having a communication hole 75 formed therein. The rotary joint 63 is rotatably supported, and a hole 76a to which the communication hole 75 can be connected. And a support shaft 50 having an ink passage 76b formed therein, a fourth pipe 77 having one end connected to the support shaft 50, and a filter 80 interposed in the middle of the fourth pipe 77 to trap paper dust and the like. An ink pump (for example, a trochoid pump) 78 that is interposed in the middle of the fourth pipe 77 and sucks the ink 56 in the fourth pipe 77, and the other end of the fourth pipe 77 are connected. And it is configured from the container 79..

  The ink recovery port 72 is formed by using an ink recovery recess formed along the printing orthogonal direction N of the outer peripheral wall 53 and a pipe fixing member 82 arranged inside the recess. The rotary joint 63 is also used as the ink supply means 54. Further, since the support shaft 50 is also used in the ink passage of the first ink supply means 54, it has a double pipe structure.

  As shown in FIGS. 1 and 4, the first cleaning unit 90 is in contact with the solenoid device 91 that is a driving source fixed to the apparatus main body 10 side, and the outer peripheral wall 25 a by driving the solenoid device 91, thereby remaining ink. Blade 92, which is an ink scraping member that changes between an ink scraping position (the phantom line position in FIG. 4) and a standby position (solid line position in FIGS. 1 and 4) spaced from the surface of the outer peripheral wall 25a. It consists of and.

  The blade 92 has a width at least equal to or larger than the width of the maximum print area, and is formed of a material that does not damage the outer peripheral wall 25a. Further, the blade 92 is set so as to come into contact with the surface of the outer peripheral wall 53 on the rotation downstream side at an angle of less than 90 degrees.

  In addition, each configuration of the second drum 36, the base paper clamp unit 37, the second ink supply unit (not shown), and the second ink collection unit (not shown) on the second printing unit 6 side is the first printing unit. Since it is the same as that of 4 side, description is abbreviate | omitted. As shown in FIG. 1, the second cleaning unit 95 has the same configuration as the first cleaning unit 90, and a solenoid device 96 that is a drive source fixed to the apparatus main body 10 side and driving of the solenoid device 96 The blade 97 is moved between the ink scraping position and the standby position.

  Next, plate making and printing control operations during two-color printing of the stencil printing apparatus 1 will be described.

  When the two-color plate making mode is selected, plate making / discharge plate processing on the first drum 25 side is executed. First, a control unit (not shown) checks whether or not the stencil sheet 12 is wound around the first drum 25. If it is wound, the stencil sheet 12 is removed from the first drum 25 and the stencil box is removed. Release to 45.

  When the evacuation process is completed, thermal piercing is performed on the stencil sheet 12 by the thermal head 15 based on the first color plate-making data read by the original reading operation. Then, the front end of the stencil sheet 12 made of the stencil is clamped by the first clamp portion 26, and the first drum 25 is rotated in this clamped state so that the stencil sheet 12 is wound around the outer peripheral wall 25a of the first drum 25. The landing process is performed. This completes the plate making operation on the first drum 25 side. Next, when the plate making operation of the first drum 25 is completed, the plate making / discharge plate processing of the second drum 36 is executed. First, the plate making unit 11 is moved from the first base paper supply position on the first drum 25 side to the second base paper supply position on the second drum 36 side by a plate making unit moving means (not shown). Next, a control unit (not shown) checks whether or not the stencil sheet 12 is wound around the second drum 36. If it is wound, the stencil sheet 12 is removed from the second drum 36 and discharged. Dispose of in the box 47. Thermal piercing is performed on the stencil sheet 12 by a thermal head 15 based on the read plate-making data of the second color. Then, similarly to the first drum 25, a plate making process in which the stencil sheet 12 thus made is wound around the second drum 36 is performed, and the plate making operation on the second drum 36 side is completed.

  Next, when the two-color printing mode is selected, the main motor (not shown) rotates to rotate the first and second drums 25 and 36, and the printing paper is fed from the paper feeding unit 3 in synchronization with this rotation. 20 is fed to the first drum 25. The fed printing paper 20 is pressed against the stencil sheet 12 of the first drum 25 by the first press roll 27, whereby a first color image is printed on the printing paper 20. The printing paper 20 on which the first color image is printed is peeled off from the outer peripheral surface of the first drum 25 by the separation claw 28, the leading edge separation air, and the separation air, and guided to the intermediate conveyance unit 5. In the intermediate conveyance unit 5, the printing paper 20 is conveyed by the movement of the endless belt 32, and the printing paper 20 is fed to the second drum 36. The fed printing paper 20 is pressed against the stencil sheet 12 of the second drum 36 by the second press roll 38, whereby a second color image is printed on the printing paper 20. The printing paper 20 on which the second color image is printed is peeled off from the outer peripheral surface of the second drum 36 by the separation claw 39, the tip separation air, and the separation air, and is guided to the belt conveyance mechanism 42. In the belt conveyance mechanism 42, the printing paper 20 is conveyed by the movement of the endless belt 42 b, and is discharged from the most downstream side of the belt conveyance mechanism 42 to the paper discharge tray 43. The printing paper 20 discharged to the paper discharge tray 43 is placed in a stacked state here.

  When printing of the set number of sheets is completed, the driving of the first and second ink supply means 54 is stopped. Thereby, the supply of ink to the outer peripheral walls 25a and 36a is stopped. The drive of the first and second ink recovery means 73 is stopped slightly later than the stop of the first and second ink supply means 54, and excess ink remaining on the outer peripheral walls 25 a and 36 a is recovered from the ink recovery port 72. The Further, the rotation of the outer peripheral walls 25a and 36a of the first and second drums 25 and 36 is stopped, and the first and second press rolls 27 and 38 are returned from the pressing position to the separated position, and the standby mode is entered. .

  Next, the monochrome printing operation will be described with reference to FIG. Hereinafter, for convenience of description, the printing drum side will be described as the second drum 36, and the non-printing drum side will be described as the first drum 25.

  When the monochromatic printing mode is selected (step S1), the stencil sheet 12 mounted on the first drum 25 and the second drum 36 is removed (step S2). Next, the plate making / plate making operation as described above is performed on the second drum 36 on the printing drum side (step S3). For the first drum 25 on the non-printing drum side, the cleaning operation is performed without performing the plate making / plate making operation (step S4). That is, the first drum 25 is rotated, the blade 92 of the first cleaning unit 90 is positioned at the ink scraping position immediately after the base paper clamp unit 26, and the ink collecting unit 73 is driven. Then, the blade 92 moves on the surface of the outer peripheral wall 25a from the rotation upstream side to the rotation downstream side. As a result, the blade 92 moves while scraping the remaining ink on the surface of the outer peripheral wall 25 a to the downstream side, and the ink scraped to the downstream side flows into the ink recovery port 72. The ink that has flowed into the ink recovery port 72 is recovered in the recovery container 79 by the ink recovery means 73. With the above operation, the remaining ink on the outer peripheral wall 25a is removed. If this cleaning operation is performed simultaneously with the plate-making operation, the time is shortened.

  Next, the main motor (not shown) is driven to rotate the first and second drums 25 and 36, and the first and second press rolls 27 and 38 are moved from the separated position to the pressed position (step). S5, S6). Then, only the second ink supply means (not shown) and the second ink recovery means (not shown) on the printing drum side are driven. The first ink supply means 54 and the first ink recovery means 73 on the non-printing drum side are not driven (step S7).

  In the paper feeding unit 3, the printing paper 20 is fed between the first drum 25 and the first press roll 27 in synchronization with the rotation of the first drum 25 (step S8). The fed printing paper 20 is conveyed while being nipped between the first drum 25 and the first press roll 27.

  Here, the ink remaining on the outer peripheral wall 25a after removing the stencil sheet 12 is easily and cleanly removed by the cleaning of the first cleaning means 90 because the outer peripheral wall 25a is an ink impermeable member. Even if the printing paper 20 is conveyed while being pressed against the outer peripheral wall 25a by the first press roll 27, it passes without being stained with ink.

  The printing paper 20 that has passed between the first drum 25 and the first press roll 27 is conveyed to the intermediate conveyance unit 5 from the outer peripheral surface of the first drum 25. In the intermediate transport unit 5, the printing paper 20 is transported by the movement of the endless belt 32 and fed to the second drum 36. The fed printing paper 20 is conveyed while being nipped between the second drum 36 and the second press roll 38. In this conveyance process, a second color image is printed on the printing paper 20. The printing paper 20 on which the second color image is printed is peeled off from the outer peripheral surface of the second drum 36 by the separation claw 39, the tip separation air, and the separation air, and is guided to the belt conveyance mechanism 42. In the belt conveyance mechanism 42, the printing paper 20 is conveyed by the movement of the endless belt 42 b, and is discharged from the most downstream side of the belt conveyance mechanism 42 to the paper discharge tray 43. The printing paper 20 discharged to the paper discharge tray 43 is placed in a stacked state here. A print image of only the second color is created on the print paper 20. Even when the printing drum side is the first drum 25 and the non-printing drum side is the second drum 36, a printed matter of only the first color can be obtained by the same operation as described above.

  When the set number of sheets has been printed (steps S9 and S10), the driving of the second ink supply unit is stopped, and the driving of the second ink collecting unit is stopped after a short delay (step S11). Thereby, it can collect | recover from an ink collection port (not shown), without leaving ink as much as possible to the outer peripheral wall 36a. Further, the rotation of the outer peripheral walls 25a, 36a of the first and second drums 25, 36 is stopped, and the first and second press rolls 27, 38 are returned from the pressing positions to the separated positions (steps S12, S13). ) Enter standby mode.

  As described above, in this stencil printing apparatus 1, after the stencil sheet 12 is removed, the ink remaining on the outer peripheral walls 25a, 36a is the first and second cleaning means 90.30 because the outer peripheral walls 25a, 36a are ink impermeable members. The printing paper 20 that is transported through the printing section where no printing is performed is transported while being pressed against the outer peripheral wall 25a (or 36a) by the press roll 27 (or 38). However, it is possible to obtain a printed matter that passes through without being stained with ink and is printed only by a printing unit that performs printing. In a printing section that does not perform printing, the printing paper 20 is reliably and stably conveyed while being nipped between the outer peripheral wall 25a (or 36a) and the press roll 27 (or 38), and the outer peripheral wall 25a. The stencil sheet 12 is not wound around (or 36a). As described above, when printing is performed only in one of the first and second printing units 4 and 6, trouble such as paper jam does not occur, and wasteful stencil paper 12 is not used.

  In this embodiment, the first and second cleaning means 90 and 95 are driven by the driving sources 91 and 96 and the outer peripheral walls 25a and 36a by the driving sources 91 and 96 to scrape the remaining ink. Since the blades 92 and 97 that change between the position and the standby position separated from the surface of the outer peripheral walls 25a and 36a are provided, the outer peripheral walls 25a and 36a are in a state where the blades 92 and 97 are positioned at the ink scraping position. , The blades 92 and 97 move while scraping the remaining ink on the surfaces of the outer peripheral walls 25a and 36a, so that the remaining ink in the entire area of the outer peripheral walls 25a and 36a can be removed. Further, since the blades 92 and 97 can be positioned at the standby position except during cleaning, the first and second cleaning means 90 and 95 can be prevented from interfering with other operations such as a printing operation.

  In this embodiment, since the ink scraping members are the blades 92 and 97, the remaining ink can be scraped off strongly and strongly. The ink scraping member may be a member that can scrape the remaining ink and push it to the downstream side of rotation, and may be, for example, a brush.

  In this embodiment, since there is an ink recovery port 72 at a position downstream of printing from the maximum print area of the outer peripheral walls 25a, 36a and an ink recovery means 73 for recovering the ink flowing into the ink recovery port 72 is provided, the blade 92 , 97 can be collected from the ink collection port 72, and wasteful ink consumption can be suppressed.

  In this embodiment, the drive source is configured by the solenoid devices 91 and 96, but may be configured by a motor, for example.

  6 and 7 show a first modification of the cleaning means, FIG. 6 is a view showing the cleaning cloth of the cleaning means in the standby position, and FIG. 7 is a view showing the cleaning cloth of the cleaning means in the cleaning position. is there.

  6 and 7, the cleaning means 100 of the first modified example has a curved pad portion 101 disposed in the vicinity of the drum 25, and the curved portion of the curved pad portion 101 is wound around the supply portion 102a. A cleaning cloth 103 which is an ink wiping member passed between the take-up portion 102b is hung. The winding unit 102b is rotated by the rotational force of a cloth moving motor (not shown). The curved pad portion 101 has an upper end rotatably supported via a support shaft 104, and a fan-shaped member 105 is fixed to one end of the curved pad portion 101. A worm wheel portion 106 is provided on the arc portion of the fan-like member 105, and a worm gear 107 is engaged with the worm wheel portion 106. A flat gear 108 is fixed to the shaft 107a of the worm gear 107, and a flat gear 110 fixed to the rotation shaft of the cloth contact motor 109 as a driving source is engaged with the flat gear 108. And between the cleaning position (position of FIG. 7) in which the curved pad part 101 contacts the outer peripheral wall 25a by the driving of the cloth contact motor 109 and the standby position (position of FIG. 6) separated from the outer peripheral wall 25a. It is moved with. The cleaning cloth sensor S1 detects that the cleaning cloth 103 is close to or close to the cloth end. The pad position sensor S2 detects, for example, a reference position of the curved pad portion 101, and the curved pad portion 101 is moved between the contact position and the standby position based on the sensor output.

  The cleaning cloth 103 is made of a material having a width equal to or larger than the width of the maximum printing area of the outer peripheral wall 25a, good ink absorbability, and a material that does not damage the outer peripheral wall 25a.

  A cleaning operation of the cleaning unit 100 will be described. The cleaning cloth 103 of the cleaning means 100 is positioned at the cleaning position with respect to the drum 25 from which the stencil sheet has been removed, and the outer peripheral wall 25a is rotated. Then, the cleaning cloth 103 slides on the surface of the outer peripheral wall 25a from the rotation upstream side to the rotation downstream side. By the sliding of the cleaning cloth 103, the residual ink on the surface of the outer peripheral wall 25a is absorbed by the cleaning cloth 103, and the ink remaining on the outer peripheral wall 25a is removed.

  In the first modified example, the cleaning means 100 includes a cloth contact motor 109, a cleaning position that contacts the outer peripheral wall 25a by driving the cloth contact motor 109, and wipes the remaining ink from the surface of the outer peripheral wall 25a. Since the cleaning cloth 103 that changes between the separated standby positions is provided, when the outer peripheral wall 25a is rotated with the cleaning cloth 103 positioned at the cleaning position, the cleaning cloth 103 causes the surface of the outer peripheral wall 25a to remain on the remaining ink. The remaining ink on the entire outer peripheral wall 25a can be removed. In addition, since the cleaning cloth 103 can be positioned at the standby position except during cleaning, the cleaning unit 100 can be prevented from hindering other operations such as a printing operation.

  In the first modification, the ink wiping member is constituted by the cleaning cloth 103, so that the remaining ink can be removed without causing any damage to the outer peripheral wall 25a.

  Further, if the cleaning cloth 103 is gradually moved by the cloth moving motor 109, the remaining ink on the outer peripheral wall 25a can be absorbed by a new portion of the cleaning cloth 103, and a desired cleaning effect can be maintained.

  8 and 9 show a second modification of the cleaning means, FIG. 8 is a view showing a state where the cleaning roll of the cleaning means is in the standby position, and FIG. 9 is a view showing a state where the cleaning roll of the cleaning means is in the cleaning position. is there.

  8 and 9, the cleaning means 120 of the second modified example is connected to a solenoid device 121 that is a drive source fixed to the apparatus main body side and a drive rod of the solenoid device 121 at one end side, A swing arm 123 swingably provided at the center, a cleaning roll 124 which is an ink wiping member rotatably supported at the tip of the swing arm 123, and ink attached to the cleaning roll 124 are removed. The cleaning cloth mechanism 125 is configured. The cleaning cloth mechanism 125 includes a cleaning cloth 125b that is in contact with the cleaning roll 124 by the curved pad portion 125a, a supply section 125c that winds up one end of the cleaning cloth 125b, and a winding that winds up the other end of the cleaning cloth 125a. It is comprised from the part 125d and the cloth movement motor (not shown) which rotationally drives the winding-up part 125d.

  A cleaning operation of the cleaning unit 120 will be described. The cleaning roll 124 of the cleaning means 120 is positioned at the cleaning position with respect to the drum 25 from which the stencil sheet has been removed, and the outer peripheral wall 25a is rotated. Then, the cleaning roll 124 moves on the surface of the outer peripheral wall 25a while rotating from the rotation upstream side to the rotation downstream side. By the movement of the cleaning roll 124, the residual ink on the surface of the outer peripheral wall 25a is absorbed by the cleaning roll 124, and the ink remaining on the outer peripheral wall 25a is removed. The ink adhering to the cleaning roll 124 is removed by being absorbed by the cleaning cloth 125b.

  In the second modified example, the cleaning unit 120 includes a solenoid device 121, a cleaning position that contacts the outer peripheral wall 25a by driving the solenoid device 121, and wipes off residual ink, and a standby position that is separated from the surface of the outer peripheral wall 25a. And the cleaning roll 124 that changes the position, the rotation of the outer peripheral wall 25a with the cleaning roll 124 positioned at the cleaning position causes the cleaning roll 124 to move while wiping off the remaining ink on the surface of the outer peripheral wall 25a. Residual ink in the entire area of the outer peripheral wall 25a can be removed. Further, since the cleaning roll 124 can be positioned at the standby position except during cleaning, the cleaning unit 120 can be prevented from hindering other operations such as a printing operation.

  In the second modification, the ink wiping member is constituted by the cleaning roll 124, so that the remaining ink can be removed without causing any damage to the outer peripheral wall 25a.

  Further, if the cleaning cloth 125b is gradually moved by the cloth moving motor, the ink adhering to the cleaning roll 124 can be absorbed by a new portion of the cleaning cloth 125b, and a desired cleaning effect can be maintained.

  In the above-described embodiment, the case where the stencil printing apparatus 1 has two drums (first and second drums 25 and 36) has been described, but the present invention can also be applied to a case where there are three or more drums. is there.

1 is a schematic configuration diagram of a stencil printing apparatus according to an embodiment of the present invention. 1 is a perspective view of a first drum according to an embodiment of the present invention. FIG. 3 shows an embodiment of the present invention and is a cross-sectional view taken along line AA in FIG. 2. FIG. 3 shows an embodiment of the present invention and is a cross-sectional view taken along line BB in FIG. 2. FIG. 5 is a flowchart at the time of monochrome printing according to an embodiment of the present invention. It is a figure which shows the state of the washing | cleaning cloth of the cleaning means which concerns on a 1st modification in a standby position. It is a figure which shows the state of the cleaning cloth of the cleaning means which concerns on a 1st modification. It is a figure which shows the state of the cleaning roll of the cleaning means which concerns on a 2nd modification in a standby position. It is a figure which shows the state of the cleaning roll of the cleaning means which concerns on a 2nd modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stencil printing apparatus 4 1st printing part 6 2nd printing part 12 Stencil base paper 20 Printing paper (printing medium)
25 first drum 25a outer peripheral wall 27 first press roll 36 second drum 36a outer peripheral wall 38 second press roll 54 ink supply means 55 ink supply port 72 ink recovery port 73 ink recovery unit 90 first cleaning unit 91 solenoid device (drive) source)
92 Blade (ink scraping member)
95 Second cleaning means 96 Solenoid device (drive source)
97 Blade (ink scraping member)
100 Cleaning means 103 Cleaning cloth (ink wiping member)
109 Cloth contact motor (drive source)
120 Cleaning means 121 Solenoid device (drive source)
124 Cleaning roll (ink wiping member)

Claims (7)

A drum having a rotatable outer peripheral wall formed of an ink impermeable member, and a stencil sheet mounted on the surface of the outer peripheral wall; and an ink supply means for supplying ink to the surface of the outer peripheral wall of the drum; A plurality of printing units having a pressing position that presses the outer peripheral wall and a press roll that shifts between the pressing positions that separate the outer peripheral wall are provided, the print medium is sequentially conveyed to the plurality of printing units, and each of these printing units rotates. The printing medium is transported between the outer peripheral wall and the press roll positioned at the pressing position, and the ink supplied to the outer peripheral wall by the ink supply means in the transport process from the perforation of the stencil sheet to the printing medium. In the stencil printing apparatus, each printed by transferring,
Each printing unit has a cleaning unit that removes ink adhering to the surface of the outer peripheral wall, and when printing is performed only in a part of the plurality of printing units, in the printing unit that does not perform printing, The outer peripheral wall is rotated by cleaning the surface of the outer peripheral wall with the cleaning means, without winding stencil paper around the cleaned outer peripheral wall, and without supplying ink from the ink supply means to the outer peripheral wall. A stencil printing apparatus, wherein the printing medium is conveyed between the press rolls positioned at a pressing position. The stencil printing apparatus according to claim 1,
The cleaning means is an ink scraper that changes between a driving source and an ink scraping position that abuts on the outer peripheral wall by driving the driving source and scrapes residual ink and a standby position that is separated from the surface of the outer peripheral wall. A stencil printing apparatus comprising a take-up member. The stencil printing apparatus according to claim 2,
The stencil printing apparatus, wherein the ink scraping member is a blade. The stencil printing apparatus according to any one of claims 1 to 3,
A stencil printing apparatus comprising an ink recovery port at a position downstream of printing from the maximum printing area of the outer peripheral wall, and ink recovery means for recovering ink flowing into the ink recovery port. The stencil printing apparatus according to claim 1 or 4,
The cleaning means includes a driving source and an ink wiping member that abuts on the outer peripheral wall by driving the driving source and changes between a cleaning position for wiping off residual ink and a standby position separated from the surface of the outer peripheral wall. A stencil printing apparatus comprising: The stencil printing apparatus according to claim 5,
The stencil printing apparatus, wherein the ink wiping member is a cleaning cloth. The stencil printing apparatus according to claim 5,
The stencil printing apparatus, wherein the ink wiping member is a cleaning roll.

Images