JP2005238560A - Stencil printing equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a printing surface from being stained and a drum from being stuck with due to the usage of a separating claw and prevent an ununiform image from developing due to the ununiform separating timing of a printing paper. <P>SOLUTION: In stencil printing equipment, which has a drum 21, on which a base stencil paper is installed, a press roll 23, which presses the printing paper sheet 30 to be fed between the drum and the press roll and turns together with the drum so as to feed the paper sheet from the upstream side in the conveying direction of the press roll between the drum and the press roll in order to transfer images from the base stencil paper sheet on the printing paper sheet during the passing process of the fed printing paper sheet between the drum and the press roll and finally deliver the printing paper sheet, on which the images are transferred, to the downstream side in the conveying direction of the press roll, a suction opening forming plate 42 having a surface acting as a paper conveying surface 43 is provided at a position near the peripheral surface on the downstream side in the conveying direction of the press roll and then a suction opening 44 surrounded by the suction opening forming plate 42 and the peripheral surface of the press roll 23 is provided and a suction fan 47 for sucking outside air of the paper conveying surface 43 through the suction opening 44. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a stencil printing apparatus that conveys printing paper while applying printing pressure to a rotating drum and performs image transfer, and particularly relates to a technique for peeling the printing paper from the drum.

  This type of stencil printing apparatus includes a scanner unit that reads image data of a document to be printed, a plate making unit that punches a stencil sheet based on image data read by the scanner unit, and a stencil sheet produced by the plate making unit. A printing unit that transports printing paper while applying printing pressure to the rotating drum and transfers the image to the printing paper, a paper feeding unit that feeds the printing paper to the printing unit, and a printing unit A paper discharge unit that discharges the printing paper printed in step 1 and a plate discharge unit that removes the stencil sheet mounted on the drum. 7 and 8 disclose a means for using an instantaneous strong wind for separation in order to surely peel off the printing paper conveyed along with the rotation of the drum and passed through the image transfer position (for example, patents). Reference 1).

  This means will be described with reference to FIG. 7. The stencil sheet 101 is mounted on the outer peripheral surface 100a of the drum 100, and rotates in the direction of arrow A by the driving force of a drum motor (not shown). The press roll 102 is movably provided at a position below the drum 100 and presses the fed printing paper 103 against the drum 100 to apply a printing pressure. A separation claw 104 is disposed downstream of the image transfer position of the drum 100 and in the vicinity of the outer peripheral surface 100 a of the drum 100, and a blower nozzle (not shown) is provided at the tip of the separation claw 104. ing. This blower nozzle is connected to a separation pump 106 via a blower pipe 105, and the separation pump 106 generates an instantaneous strong wind in synchronization with the rotation of the drum 100 using a drum motor as a drive source.

  In the above configuration, the printing paper 103 is conveyed while applying a printing pressure to the outer peripheral surface 100 a of the rotating drum 100, and image transfer is performed from the stencil sheet 101 to the printing paper 103 in this conveyance process. When the conveyance leading edge of the printing paper 103 comes to the rotation position where the image transfer is completed, a strong wind for separation is instantaneously blown from the leading edge of the separation claw 104 between the conveyance leading edge of the printing paper 103 and the outer peripheral surface 100a of the drum 100. The leading edge of the printing paper 103 is peeled off from the drum 100 by the strong wind for separation. As shown in FIG. 8, the conveyance leading end side of the printing paper 103 peeled off from the drum 100 is guided to the lower side of the separation claw 104, and the printing paper 103 guided below the separation claw 104 is sequentially pulled from the drum 100. It is peeled off. The printing paper 103 peeled off from the drum 100 is conveyed to a predetermined paper discharge path.

That is, since the printing paper 103 immediately after printing adheres to the drum 100 side due to the viscosity of the ink, a strong separation strong wind is blown between the conveyance leading edge of the printing paper 103 and the outer peripheral surface 100a of the drum 100 to forcibly. The printing paper 103 is reliably separated from the drum 100 by separating the leading edge of the printing paper 103 from the drum 100 and guiding the conveyance leading edge of the printing paper 103 separated from the drum 100 by the separation claw 104.
JP 2003-136823 A

  However, the conventional stencil printing apparatus has a problem that the printing paper 103 may come into contact with the separation claw 104 and the printing surface becomes dirty when the printing surface of the printing paper 103 comes into contact with the separation claw 104. In addition, since the separation claw 104 is disposed in the vicinity of the drum 100, there is a possibility that the separation claw 104 may pierce the drum 100 during a trouble. Furthermore, since the air blow from the separation pump 106 is generated only at the timing when the conveyance leading end side of the printing paper 103 is peeled off from the drum 100, the timing at which each part downstream from the conveyance leading end side of the printing paper 103 is peeled off from the drum 100 is determined. There is a possibility that image unevenness due to uneven peeling timing may occur.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a stencil printing apparatus that can prevent the printing surface from being soiled and stuck to the drum due to the use of the separation claw, and can prevent image unevenness due to uneven peeling timing of the printing paper. And

  According to the first aspect of the invention for achieving the above object, a stencil sheet is mounted on the outer peripheral surface, a drum that is driven to rotate, and a press that presses printing paper fed between the drum and rotates together with the drum. The printing paper is fed between the drum and the press roll from the upstream side of conveyance of the press roll, and the fed printing paper passes between the drum and the press roll. In the stencil printing apparatus, the printing paper is subjected to image transfer from the stencil sheet in the process of passing, and the printing paper on which the image has been transferred is discharged to the downstream side of conveyance of the press roll. A suction port forming plate whose surface is the paper transport surface is provided at a position close to the peripheral surface on the downstream side of the transport, and a suction port surrounded by the suction port forming plate and the peripheral surface of the press roll is provided. , Characterized in that a suction fan for sucking the outside air of the paper transport surface than the suction opening.

  A second aspect of the present invention is the stencil printing apparatus according to the first aspect, wherein the press roll is freely movable between a pressing position for pressing the drum and a standby position spaced from the drum, and the suction roll. The mouth forming plate is movably provided together with the press roll.

  A third aspect of the present invention is the stencil printing apparatus according to the first aspect, wherein a substantial width of the suction port is set to be larger than a maximum width of the printing paper that can be fed.

  A fourth aspect of the invention is the stencil printing apparatus according to the first aspect of the invention, wherein the suction port is divided and arranged by a plurality of paper suction prevention protrusions arranged along the paper transport direction.

  A fifth aspect of the present invention is the stencil printing apparatus according to the first aspect, wherein the suction port forming plate is a suction box in which a suction air is generated from the suction port by reducing the inside by driving the suction fan. It is formed as a part, and the suction unit is configured by assembling the press roll into the suction box.

  A sixth aspect of the present invention is the stencil printing apparatus according to the fifth aspect, wherein the drum is rotatably assembled to the suction box.

  According to the first aspect of the present invention, the suction port is arranged at a position immediately after the printing pressure from the drum and the press roll is released and at a position sufficiently close to the drum, and the printing paper is printed by a very strong suction force. Therefore, the printing paper can be peeled from the drum only with the suction air. Accordingly, it is possible to prevent the printing surface from being soiled or stuck to the drum due to the use of the separation claw. In addition, if suction is performed from the suction port during the entire passage from the leading edge of the printing paper to the trailing edge, any part of the printing paper from the leading edge of the printing paper to the trailing edge will be at a position that has passed through the press roll. Always peeled from the drum. Accordingly, it is possible to prevent image unevenness due to uneven peeling timing of the printing paper.

  According to the second aspect of the present invention, the suction port forming plate is disposed at a position close to the drum only when a printing operation is performed with the press roll as a pressing position with respect to the drum, and at other times, separated from the drum together with the press roll. Therefore, the suction port forming plate does not get in the way during the maintenance or replacement of the drum.

  According to the invention of claim 3, since a suction force can be applied over the entire width of the printing paper, the printing paper can be peeled off from the drum reliably and stably.

  According to the invention of claim 4, the printing paper is not sucked into the suction port by the suction force.

  According to the invention of claim 5, if the suction unit is removed from or attached to the apparatus main body, the suction box and the press roll can be removed or attached. Therefore, maintenance and replacement of the suction box and the press roll are easy.

  According to the invention of claim 6, maintenance and replacement of the drum are also easy.

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

  1 to 6 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 suction unit, FIG. 3 is a plan view of the suction unit, and FIG. 5 is a cross-sectional view taken along the line A-A, FIG. 5 is a cross-sectional view taken along the line BB in FIG. 3, and FIG. 6 is a cross-sectional view of a suction unit and the like for explaining the operation of peeling the printing paper from the drum.

  As shown in FIG. 1, the stencil printing apparatus 1 includes a document reading unit (not shown), a plate making unit 2, a printing unit 3, a paper feed unit 4, a paper discharge unit 5 and a paper discharge unit 6. It is configured.

  The document reading unit optically reads image data of a document transported by a document setting table, a document transport roll that transports a document placed thereon, and the document transport roll, and converts the image data into an electrical signal. Type image sensor. Then, the document placed on the document setting table is transported by the document transport roll, and the image sensor reads the image data of the transported document.

  The plate making unit 2 is disposed at a position opposite to the thermal head 12, a base paper storage unit 11 that stores the rolled long stencil base paper 10, a thermal head 12 that is disposed downstream of the base paper storage unit 11. A platen roll 13, a pair of base paper feed rolls 14, 14 disposed downstream of the transport of the platen roll 13 and the thermal head 12, and a light pulse motor (not shown) that rotationally drives the platen roll 13 and the base paper feed roll 14. And a base paper cutter 15 disposed downstream of the pair of base paper feed rolls 14 and 14.

  Then, the long stencil sheet 10 is conveyed by the rotation of the platen roll 13 and the pair of base paper feed rolls 14 and 14, and each point-like heating element of the thermal head 12 is selectively selected based on the image data read by the image sensor. By making an exothermic operation, the stencil sheet 10 is thermally perforated to make a plate, and the stencil sheet 10 thus made is cut with a stencil cutter 15 to produce a stencil sheet 10 having a predetermined length.

  The printing unit 3 includes a drum 21 that rotates in the direction of arrow A in FIG. 1 by the driving force of the motor 20, a base paper clamp unit 22 that is provided on the outer peripheral surface of the drum 21 and clamps the leading end of the stencil base paper 10, and the drum 21. An ink supply means (not shown) for supplying ink to the upper surface of the print area, an ink collection means (not shown) for collecting excess ink that protrudes from the surface outside the print area of the drum 21, and a drum A press roll 23 disposed below, and a suction unit 24 that peels from the drum 21 the printing paper 30 that has passed between the drum 21 and the press roll 23 and has been image-transferred are provided.

  The drum 21 is rotationally driven by a drum / press roll driving means 50 described later. The outer peripheral wall 21a of the drum 21 is formed of an ink impermeable member that has rigidity and does not allow ink to pass. Further, the outer peripheral surface of the outer peripheral wall 21a 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 22 is rotatably supported by the outer peripheral wall 21a of the drum 21 and protrudes from the outer peripheral wall 21a in the clamp release state indicated by the phantom line in FIG. 1, but in the clamp state indicated by the solid line in FIG. It is provided so as not to protrude from the wall 21a. Accordingly, the stencil sheet 22 can clamp the stencil sheet 10 without protruding onto the outer peripheral wall 21a.

  The press roll 23 is configured to be able to change between a pressing position where it is pressed against the outer peripheral surface of the drum 21 by a drum / press roll driving means 50 described later and a standby position which is separated from the outer peripheral surface of the drum 21. The press roll 23 is always positioned at the pressing position during the printing mode period (including trial printing), and is positioned at the standby position during the period other than the printing mode.

  Then, the leading end of the stencil sheet 10 conveyed from the plate making unit 2 is clamped by the stencil sheet clamping unit 22, and in this clamped state, the drum 21 is rotated so that the stencil sheet 10 is wound around the outer peripheral surface of the drum 21. The printing paper (printing medium) 30 fed from the paper feeding unit 4 in synchronism with the rotation of the paper is pressed against the stencil paper 10 wound around the drum 21 by the press roll 23, whereby the stencil paper 10 is applied to the printing paper 30. The ink is transferred from the perforations to print an image, and the image-printed printing paper 30 is peeled from the drum 21 by the suction force of the suction unit 24.

  The paper feed unit 4 includes a paper feed tray 31 on which the print paper 30 is stacked, primary paper feed rolls 32 and 33 that transport only the uppermost print paper 30 from the paper feed base 31, and the primary paper feed. The printing paper 30 conveyed by the rolls 32 and 33 has a pair of secondary paper feed rolls 34 and 34 that convey the printing paper 30 between the drum 21 and the press roll 23 in synchronization with the rotation of the drum 21. The rotation of the motor 20 is selectively transmitted to the primary paper feed rolls 32 and 33 via a paper feed clutch (not shown).

  The paper discharge unit 5 includes a conveyance path 35 through which the printing paper 30 peeled from the drum 21 is conveyed, and a paper discharge tray 36 on which the printing paper 30 discharged from the conveyance path 35 is placed.

  The plate discharging unit 6 guides the leading end of the stencil sheet 10 unclamped from the outer peripheral surface of the drum 26 and transports the guided used stencil sheet 10 while peeling it from the drum 21, and this plate discharging transport. And a stencil box 38 for storing the stencil sheet 10 conveyed by the means 37.

  Next, the configuration of the suction unit 24 will be described. As shown in FIGS. 2 to 5, the suction unit 24 includes a rectangular parallelepiped suction box 40 whose inside is substantially sealed. A pair of movable side plates 41, 41 is supported on the upper portion of the suction box 40 so as to be movable up and down, and the press roll 23 is rotatably supported between the pair of movable side plates 41, 41, and a suction port is formed. The plate 42 is fixed. That is, the suction port forming plate 42 is moved up and down together with the press roll 23. The suction port forming plate 42 is disposed at a position close to the peripheral surface on the downstream side of the conveyance of the press roll 23, and the upper surface (front surface) of the suction port forming plate 42 is between the press roll 23 and the conveyance passage 35. Are formed as a sheet conveying surface 43 connecting the two.

  Further, a notch is formed at equal intervals in the direction orthogonal to the paper transport direction on the side of the press roll 23 of the suction port forming plate 42, and a suction port 44 is provided by this notch and the peripheral surface of the press roll 23. . The substantial width D of the suction port 44 is set to be larger than the maximum width of the print paper 30 that can be fed. The suction port 44 is divided into a plurality of pieces by a plurality of paper suction prevention protrusions 45 arranged in the paper transport direction.

  A fan cover 46 is attached to the rear surface of the suction box 40, and a suction fan 47 is disposed in the fan cover 46. When the suction fan 47 is driven, the inside of the suction box 40 is depressurized, and the outside air of the sheet conveying surface 43 is sucked into the suction box 40 from the suction port 44 by this depressurization.

  The suction box 40 is provided with a drum / press roll driving means 50. The drum / press roll driving means 50 has a motor 20 fixed at an outer position of the suction box 40, and the rotation of the motor 20 is guided to the input side of the clutch 52 via the timing belt 51. An eccentric cam 53 is connected to the output side of the clutch 52, and one end side of the swing arm 54 is disposed above the eccentric cam 53. The other end of the swing arm 54 is connected to a support shaft 55 that connects the pair of movable side plates 41. One end of a tension coil spring 56 is hung on one end side of the swing arm 54, and the press roll 23 is biased toward the pressing position by the spring force of the tension coil spring 56. The other end side of the tension coil spring 56 is hung on a printing pressure adjusting rod 57, and the printing pressure can be freely adjusted by operating the printing pressure adjusting rod 57.

  When the driving force of the motor 20 is transmitted to the eccentric cam 53 by the clutch 52 so that the eccentric cam 53 does not interfere with one end side of the swing arm 54, the press roll 23 pushes the spring force of the tension coil spring 56. Located at the pressed position as pressure. Further, when the driving force of the motor 20 is transmitted to the eccentric cam 53 by the clutch 52, and the eccentric cam 53 is positioned to interfere with one end side of the swing arm 54, the swing arm 54 becomes the spring force of the tension coil spring 56. The press roll 23 is positioned at the standby position.

  Further, the drum 21 is rotatably supported at a position above the press roll 23 of the suction box 40. The drum / press roll driving means 50 has a first gear 58 fixed to the rotation shaft of the motor 20, and the first gear 58 meshes with a second gear 59 fixed to the support shaft of the drum 21. When the motor 20 rotates, the rotation is transmitted to the drum 21 via the first gear 58 and the second gear 59, whereby the drum 21 is rotated.

  Next, the operation of the stencil printing apparatus 1 will be briefly described.

  First, when the plate making mode is selected, the plate making unit 2 transports the stencil sheet 10 by the rotation of the platen roll 13 and the base paper feed roll 14, and generates a large number of heats of the thermal head 12 based on the image data read by the document reading unit. When the body selectively generates heat, the stencil sheet 10 is thermally perforated to make a plate, and a predetermined portion of the stencil sheet 10 is cut with a base paper cutter 15 to make a stencil sheet 10 having a desired size.

  In the printing unit 3, the front end of the stencil sheet 10 made by the plate making unit 2 is clamped by the base sheet clamp unit 22 of the drum 21, and the drum 21 is rotated in this clamped state so that the stencil sheet 10 is moved to the outer peripheral wall 21 a of the drum 21. Wrap around and plate.

  Next, when the printing mode is selected, in the printing unit 3, the drum 21 and the suction fan 47 are driven to rotate, and the ink supply unit and the ink collection unit are started to be driven. Then, ink is supplied to the outer peripheral wall 21a of the drum 21, and the supplied ink is held between the outer peripheral wall 21a of the drum 21 and the stencil sheet 10, and the press roll 23 is displaced from the standby position to the pressing position. The

  In synchronization with the rotation of the drum 21, the paper feeding unit 4 feeds the printing paper 30 between the drum 21 and the press roll 23. The fed printing paper 30 is pressed against the outer peripheral wall 21 a of the drum 21 by the press roll 23 and is conveyed by the rotation of the drum 21. That is, the printing paper 30 is conveyed while being in close contact with the stencil sheet 10.

  In parallel with the conveyance of the printing paper 30, the ink held between the outer peripheral wall 21 a of the drum 21 and the stencil sheet 10 is diffused downstream in the printing direction while being squeezed by the pressing force of the press roll 23. At the same time, the diffused ink oozes out from the perforations of the stencil sheet 10 and is transferred to the printing paper 30 side. As a result, the ink image is transferred to the printing paper 30 while passing between the outer peripheral wall 21 a of the drum 21 and the press roll 23. As shown in FIG. 6, the printing paper 30 that has passed between the outer peripheral wall 21 a of the drum 21 and the press roll 23 receives the suction air from the suction port 44, and is peeled off from the drum 21. The separated printing paper 30 is discharged to a paper discharge tray 36 through a conveyance path 35 and stacked there.

  During the printing operation, excess ink that has flowed out downstream of the maximum printing area of the outer peripheral wall 21a of the drum 21 is collected by the ink collecting means.

  When printing of the set number of prints is completed, the rotation of the drum 21 and the suction fan 47 is stopped, and the drive of the ink supply unit is stopped. Thereby, the supply of ink to the outer peripheral wall 21a of the drum 21 is stopped. The drive of the ink collecting means is stopped slightly later than the stop of the ink supply means, and excess ink remaining on the outer peripheral wall 21a of the drum 21 is collected by the ink collecting means. Further, the press roll 23 is returned from the pressing position to the standby position. Upon completion of the above operation, the standby mode is entered.

  When the plate discharging mode is selected by starting a new plate making or the like, the base paper clamp part 22 of the drum 21 is displaced to the clamp release position, and the leading end side of the stencil base paper 10 which has been released from the clamp is transported as the drum 21 rotates. It is guided by the means 37 and stored in the discharge box 38.

  Next, the peeling operation of the printing paper 30 from the drum 21 in the operation process will be described. As shown in FIG. 4, the press roll 23 is positioned at the pressing position, and the leading end of the printing paper 30 that has received the image transfer is led out between the drum 21 and the press roll 23. Here, the suction port 44 is disposed at a position immediately after the printing pressure from the drum 21 and the press roll 23 is released and at a position sufficiently close to the drum 21, and the printing paper 30 passes over the suction port 44. Since the printing paper 30 is sucked by a very strong suction force, the printing paper 30 is peeled off from the drum 21 only by suction air. Accordingly, it is possible to prevent the printing surface from becoming dirty and the drum 21 from being pierced by the use of the separation claw. Further, in order to perform suction from the suction port 44 in the entire passage process from the conveyance leading end of the printing paper 30 to the conveyance trailing end, as shown in FIG. It is always peeled off from the drum 21 at the position where the press roll 23 is removed. Therefore, image unevenness due to uneven peeling timing of the printing paper 30 can be prevented.

  In the above-described embodiment, the press roll 23 is movable between the pressing position for pressing the drum 21 and the standby position separated from the drum 21, and the suction port forming plate 42 is provided so as to be movable together with the press roll 23. The suction port forming plate 42 is disposed at a position close to the drum 21 only when a printing operation is performed with the press roll 23 being pressed against the drum 21, and at a position separated from the drum 21 together with the press roll 23 at other times. Therefore, the suction port forming plate 42 does not get in the way during maintenance or replacement of the drum 21.

  In the embodiment, since the substantial width D of the suction port 44 is set to be larger than the maximum width of the print paper 30 that can be fed, a suction force can be applied over the entire width of the print paper 30. Therefore, the printing paper 30 can be peeled off from the drum 21 reliably and stably.

  In the embodiment, since the suction port 44 is divided and arranged by the plurality of paper suction prevention protrusions 45 disposed along the paper transport direction, the printing paper 30 is not sucked into the suction port 44 by the suction force.

  In the above-described embodiment, the suction port forming plate 42 is formed as a part of the suction box 40 whose pressure is reduced by driving the suction fan 47 and suction air is generated from the suction port 44. Since the suction unit 24 is configured by assembling the head 23, the suction box 40 and the press roll 23 can be removed and attached by removing or attaching the suction unit 24 from the apparatus main body. Therefore, maintenance and replacement of the suction box 40 and the press roll 23 are easy. Further, since the drum 21 is also assembled in the suction box 40, maintenance and replacement of the drum 21 are easy.

  In the above-described embodiment, the drum 21 has an outer peripheral wall 21 a formed of an ink impermeable member, and diffuses ink held between the surface of the outer peripheral wall 21 a and the stencil sheet 10 while squeezing with the press roll 23. In this case, the printing paper 30 is used for image transfer. However, the outer peripheral wall 21a of the drum 21 is formed of an ink permeable member, and the ink supplied from the inner surface of the outer peripheral wall 21a is diffused to the entire inner surface of the outer peripheral wall 21a. You may use what performs image transfer to the printing paper 30 by making it apply | coat.

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 suction unit according to an embodiment of the present invention. 1 is a plan view of a suction unit according to an embodiment of the present invention. FIG. 4 shows an embodiment of the present invention and is a cross-sectional view taken along line AA in FIG. 3. FIG. 5 is a cross-sectional view showing the embodiment of the present invention and taken along line BB in FIG. 3. FIG. 3 is a cross-sectional view of a suction unit and the like illustrating an operation of peeling the printing paper from the drum according to the embodiment of the present invention. It is a block diagram of the principal part of a stencil printing apparatus showing a conventional example. It is a figure which shows peeling operation | movement by the separation nail | claw of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stencil printing apparatus 21 Drum 23 Press roll 24 Suction unit 30 Printing paper 40 Suction box 42 Suction port formation plate 43 Paper transport surface 44 Suction port 45 Paper suction prevention protrusion 47 Suction fan

Claims (6)

A stencil sheet is mounted on the outer peripheral surface, and has a drum that is driven to rotate and a press roll that presses the printing paper fed between the drum and rotates together with the drum. The printing paper is fed between the drum and the press roll from the side, and the printing paper is fed from the stencil paper in the process of passing the fed printing paper between the drum and the press roll. In the stencil printing apparatus which has received the image transfer, and the printing paper on which the image has been transferred is discharged to the downstream side of conveyance of the press roll,
A suction port forming plate whose surface is a paper transport surface is provided at a position close to the peripheral surface on the downstream side of the transport of the press roll, and a suction port surrounded by the suction port forming plate and the peripheral surface of the press roll is provided. A stencil printing apparatus comprising a suction fan for sucking air outside the sheet conveying surface from the suction port. The stencil printing apparatus according to claim 1,
The stencil characterized in that the press roll is movable between a pressing position for pressing against the drum and a standby position spaced apart from the drum, and the suction port forming plate is movably provided together with the press roll. Printing device. The stencil printing apparatus according to claim 1,
The stencil printing apparatus according to claim 1, wherein a substantial width of the suction port is set to be larger than a maximum width of the printing paper that can be fed. The stencil printing apparatus according to claim 1,
The stencil printing apparatus, wherein the suction port is divided and arranged by a plurality of paper suction prevention protrusions arranged along the paper conveyance direction. The stencil printing apparatus according to claim 1,
The suction port forming plate is formed as a part of a suction box whose inside is depressurized by driving the suction fan and suction air is generated from the suction port, and the suction unit is assembled with the press roll in the suction box. A stencil printing apparatus characterized by being configured. The stencil printing apparatus according to claim 5,
A stencil printing apparatus, wherein the drum is rotatably assembled to the suction box.

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