JP4395390B2 - Stencil printing machine - Google Patents

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. 9 and 10 disclose means for using a momentary separation strong wind to reliably peel off the printing paper that has been conveyed 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. 9. The drum 100 has a stencil sheet 101 mounted on its outer peripheral surface 100a, 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. 10, the conveyance leading end side of the printing paper 103 separated from the drum 100 is guided to the lower side of the separation claw 104, and the printing paper 103 guided to the lower side of 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. Further, since the air blow from the separation pump 106 is generated only at the timing at which the conveyance leading end side of the printing paper 103 is peeled off from the drum 100, the timing at which each portion of the printing paper 103 from the conveyance leading end side to the rear end side is peeled off from the drum 100. Is not stable, and 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 nozzle is provided at an adjacent position on the downstream side of the conveyance between the suction position close to the outer peripheral surface of the drum and the transport track position spaced apart from the outer peripheral surface of the drum. A suction fan that sucks outside air on the drum side, biases the suction nozzle toward the suction position side, and suction force acting on the suction nozzle when the suction nozzle is closed with printing paper Also provided is a biasing means having a weak biasing force.

  A second aspect of the present invention is the stencil printing apparatus according to the first aspect, wherein the press roll is movable between a pressing position for pressing against the drum and a standby position for separating from the drum. When the roll is located at the pressing position, the suction nozzle is moved to the suction position by the urging force of the urging means, and when the press roll is located at the standby position, the suction nozzle is conveyed against the urging force of the urging means. It is characterized by following and changing the orbital position.

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

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

  A fifth aspect of the present invention is the stencil printing apparatus according to the first aspect, wherein the suction nozzle is dividedly arranged in a direction orthogonal to the paper transport direction, and biasing means for biasing each suction nozzle toward the transport track position side. Are provided.

  A sixth aspect of the present invention is the stencil printing apparatus according to the first aspect, wherein the suction fan is configured to perform both suction from the suction nozzle and suction to the transport passage. .

  According to the invention of claim 1, since the suction nozzle is disposed at a position immediately after the printing pressure from the drum and the press roll is released and at a position sufficiently adjacent to the drum, the printing paper is very strong. It is sucked by the suction nozzle by the suction force. When the printing paper gradually blocks the suction nozzle and the suction force acting on the suction nozzle exceeds the biasing force of the biasing means, the suction nozzle moves to the transport track position while sucking the front end side of the print paper, and printing The conveyance front end side of the sheet is peeled off from the drum and changed to a track having a large peeling angle with respect to the drum. And since the suction force of the suction nozzle works efficiently on the peeling action on the printing paper conveyed on the conveyance locus having a large peeling angle with respect to the drum, a stable peeling track can be obtained. 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, any part of the printing paper from the leading end to the trailing end of the printing paper is reliably peeled off from the drum at the position where the press roll is removed. 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 nozzle 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 the position apart from the drum together with the press roll. Therefore, the suction nozzle does not get in the way during 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 of the suction nozzle by the suction force.

  According to the invention of claim 5, when the printing paper passes over the suction nozzle, only the suction nozzle corresponding to the width of the printing paper is changed from the suction position to the transport track position, and the other suction nozzles are sucked close to the drum. Since it is maintained at the position, the suction of excess air can be suppressed, so that a decrease in suction force can be suppressed to a minimum, and a stable peeling track can be maintained.

  According to the sixth aspect of the present invention, since the suction of the suction nozzle and the suction to the transport passage are performed by the same suction fan, it is possible to reduce the number of suction fans and simplify the structure.

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

  1 to 6 show a first 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 sectional view of the suction unit, and FIG. FIG. 5 is a cross-sectional view of a state where the leading end of the printing paper is transported to a position where the leading end of the printing paper reaches the suction nozzle, FIG. 5 is a cross-sectional view of a state where the leading end of the printing paper passes over the suction nozzle, FIG. 3 is a cross-sectional view of a state where a press roll is located at a standby position.

  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.

  A document reading unit (not shown) optically reads a document setting table, a document transport roll for transporting a document placed thereon, and image data of the document transported by the document transport roll, and electrically reads it. A contact-type image sensor that converts signals. 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 stencil, 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 is a drum 21 that rotates in the direction of arrow A in FIG. 1 by a driving force of a motor (not shown), and a base paper clamping 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 an ink supply means (not shown) for supplying ink to the surface above the print area of the drum 21 and 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 press roll 23 disposed below the drum, 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 is image-transferred.

  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 through. 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 press roll driving means (not shown) 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 primary paper feed rollers 32 and 33 are configured to selectively transmit the rotation of a motor (not shown) via a paper feed clutch (not shown).

  The paper discharge unit 5 includes a conveyance belt means 35 for conveying the printing paper 30 peeled from the drum 21, a suction fan 35 a for sucking the printing paper 30 onto the belt of the conveyance belt means 35, and a conveyance belt means. And a paper discharge tray 36 on which the printing paper 30 discharged from the paper 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 6, the suction unit 24 includes a rectangular parallelepiped suction box 40 whose inside is substantially sealed. A pair of movable side plates (not shown) is supported on 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.

  Further, a suction nozzle 41 is disposed at a position near the upper surface of the suction box 40 and the peripheral surface on the downstream side of the conveyance of the press roll 23. The suction nozzle 41 passes under the press roll 23 and has a rotation fulcrum portion 42 at the upstream conveyance position of the press roll 23, and swings in the direction of arrow B (shown in FIG. 3) around the rotation fulcrum portion 42. By moving, a suction position (solid line position in FIG. 3) that is brought close to the drum 21 and a transport track position that is separated from the drum 21 and substantially the same height as the belt path of the transport belt means 35 (broken line position in FIG. 6 position).

  The suction nozzle 41 is provided with an interference sliding member 43 that interferes with the lower surface of the press roll 23, and a spring 44, which is a biasing means that biases the suction nozzle 41 toward the suction position, is applied. The suction nozzle 41 moves so as to follow the press roll 23. That is, when the press roll 23 is located at the pressing position, the suction nozzle 41 is conveyed by the spring force of the spring 44, and when the press roll 23 is located at the standby position, the suction nozzle 41 is conveyed against the spring force of the spring 44. Change following the orbital position. However, when the suction nozzle 41 is in the suction position, it can move to the transport track position against the spring force of the spring 44. The spring force of the spring 44 is set to a force that is weaker than the suction force that acts on the suction nozzle 41 in a state of being blocked by the printing paper 30.

  The substantial width D of the suction nozzle 41 is set to be larger than the maximum width of the print paper 30 that can be fed. The suction port 41a of the suction nozzle 41 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 on the drum 21 side from the suction port 41a of the suction nozzle 41 is sucked into the suction box 40 by this decompression.

  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. The printing paper 30 that has passed between the outer peripheral wall 21a of the drum 21 and the press roll 23 is peeled off from the drum 21 by the suction air from the suction nozzle 41, and the printing paper 30 separated from the drum 21 is The paper is discharged onto a paper discharge tray 36 through the 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 suction nozzle 41 is located at the suction position. In this state, as shown in FIG. 4, the leading end of the printing paper 30 is led out between the drum 21 and the press roll 23. Here, since the suction nozzle 41 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, the leading edge of the printing paper 30 is The suction nozzle 41 is sucked by a very strong suction force. When the printing paper 30 gradually closes the suction port 41a of the suction nozzle 41 and the suction force acting on the suction nozzle 41 exceeds the spring force of the spring 44, the suction nozzle 41 sucks the conveyance leading end side of the printing paper 30. In this state, it moves in the direction of arrow B1 in FIG. Then, as shown in FIG. 5, the conveyance leading end side of the printing paper 30 is peeled from the drum 21 and changed to a track having a large peeling angle a with respect to the drum 21. Since the suction force of the suction nozzle 41 efficiently acts on the peeling action on the printing paper 30 that is conveyed on the conveyance locus having a large peeling angle a with respect to the drum 21, a stable peeling track is obtained. Therefore, it is possible to prevent the printing surface from being soiled or stuck to the drum 21 due to the use of the separation claw. In addition, any part from the leading end of the printing paper 30 to the trailing end of the printing paper 30 is surely peeled off from the drum 21 at the position where the press roll 23 is removed by the above-described transport path. Therefore, image unevenness due to uneven peeling timing of the printing paper 30 can be prevented.

  In the above 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 nozzle 41 is provided movably together with the press roll 23. The suction nozzle 41 is disposed at a position close to the drum 21 only when a printing operation is performed with the press roll 23 as a pressing position with respect to 21, and in other cases, the suction nozzle 41 moves in the direction of the arrow B <b> 1 together with the press roll 23 from the drum 21. The suction nozzle 41 does not get in the way during the maintenance or replacement work of the drum 21 because it is shifted to the separated transport track position. For example, as shown by the phantom line in FIG. 6, when the base paper clamp portion 22 is arranged at a position protruding from the outer peripheral surface of the drum 21, the suction nozzle 41 also follows the direction of the arrow B <b> 1 together with the press roll 23. Since it moves, it is not necessary to provide a means for avoiding interference with the base paper clamp unit 22.

  In the embodiment, since the substantial width D of the suction nozzle 41 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 41a of the suction nozzle 41 is divided and arranged by the plurality of paper suction prevention protrusions 45 arranged along the paper transport direction, the printing paper 30 is sucked into the suction port 41a by the suction force. There is nothing.

  In the above-described embodiment, the transport track position of the suction nozzle 41 is set to substantially the same height as the belt path of the transport belt means 35, so that the printing paper 30 led out between the drum 21 and the press roll 23 is smoothly discharged. It is conveyed to the belt path of the paper unit 5.

  FIG. 7 is a perspective view of the suction unit 24A according to the second embodiment. As shown in FIG. 7, the plurality of suction nozzles 41 </ b> A to 41 </ b> F are divided and arranged in a direction orthogonal to the paper transport direction. Each of the suction nozzles 41A to 41F is hung by a spring (not shown) which is a biasing means for biasing the suction nozzles 41A to 41F toward the transport track position, and each suction nozzle 41A to 41F is configured to move independently. Has been. Since other configurations are the same as those of the first embodiment, description thereof will be omitted to avoid redundant description.

  In the second embodiment, when the printing paper passes over the suction nozzles 41A to 41F, only the suction nozzles 41A to 41F corresponding to the width of the printing paper are changed from the suction position to the transport trajectory position, and the other suction nozzles 41A to 41A are used. Since 41F is maintained at the suction position close to the drum, the suction of excess air can be suppressed, the decrease in suction force can be suppressed to a minimum, and a stable peeling track can be maintained.

  FIG. 8 shows a third embodiment and is a schematic configuration diagram of a stencil printing apparatus 1A. As shown in FIG. 8, the suction box 50 has a size that covers not only the suction nozzle 41 but also the entire lower surface of the conveying belt means 35, and a single suction fan 51 that depressurizes the inside of the suction box 50 is installed. Yes. Suction ports (not shown) are formed at lower surface portions of the suction nozzle 41 and the conveying belt means 35. A suction force adjustment plate 52 is disposed inside the suction box 50, and the suction ratio between the suction force on the suction nozzle 41 side and the suction force on the conveyor belt means 35 side is adjusted by the suction force adjustment plate 52. .

  Further, since the other configuration is the same as that of the first embodiment, the same components in FIG.

  In the third embodiment, since suction by the suction nozzle 41 and suction to the transport belt means 35 are performed by the same suction fan 51, it is possible to reduce the number of suction fans 51, simplify the structure, and the like. Further, both suction forces are adjusted to a desired one by the suction force adjusting plate 52.

  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 a first embodiment of the present invention. 1 is a perspective view of a suction unit according to a first embodiment of the present invention. It is sectional drawing of the suction unit which shows 1st Embodiment of this invention. FIG. 3 is a cross-sectional view illustrating the first embodiment of the present invention, in a state where the leading end of the printing paper is conveyed to a position where the leading end of the printing paper reaches the suction nozzle. FIG. 2 is a cross-sectional view illustrating the first embodiment of the present invention, with the leading end of the printing paper passing over the suction nozzle and the suction nozzle being positioned at the transport track position. It is sectional drawing of the state which shows 1st Embodiment of this invention and a press roll is located in a standby position. It is a perspective view of a suction unit, showing a second embodiment of the present invention. FIG. 4 is a schematic configuration diagram of a stencil printing apparatus according to a third 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 1,1A Stencil printing apparatus 21 Drum 23 Press roll 30 Printing paper 41 Suction nozzle 41a Suction port 44 Spring (biasing means)
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 nozzle is provided at a position adjacent to the conveyance downstream side of the press roll so as to be movable between a suction position close to the outer peripheral surface of the drum and a transport track position separated from the outer peripheral surface of the drum. A suction fan that sucks outside air on the drum side, biases the suction nozzle toward the suction position side, and suction force acting on the suction nozzle when the suction nozzle is closed with printing paper A stencil printing apparatus comprising urging means having a weak urging force. The stencil printing apparatus according to claim 1,
The press roll is movable between a pressing position that presses against the drum and a standby position that is separated from the drum, and when the press roll is located at the pressing position, the suction nozzle is driven by the biasing force of the biasing means. The stencil printing apparatus is characterized in that when the press roll is located at the suction position and the press roll is located at the standby position, the suction nozzle follows and changes to the transport track position against the urging force of the urging means. The stencil printing apparatus according to claim 1,
The stencil printing apparatus according to claim 1, wherein a substantial width of the suction nozzle is set to be larger than a maximum width of printing paper that can be fed. The stencil printing apparatus according to claim 1,
The stencil printing apparatus, wherein the suction port of the suction nozzle 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 stencil printing apparatus, wherein the suction nozzle is divided and arranged in a direction orthogonal to the paper transport direction, and is provided with biasing means for biasing each suction nozzle toward the transport track position. The stencil printing apparatus according to claim 1,
The stencil printing apparatus, wherein the suction fan is configured to perform both suction from the suction nozzle and suction to the transport passage.

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