JP5098055B2 - Stencil printing machine - Google Patents

Description

  The present invention relates to a stencil printing apparatus capable of duplex printing.

  Various stencil printing apparatuses have been proposed that can perform double-sided printing that prints on both front and back sides of paper for the purpose of reducing paper consumption and document storage space. The following are proposed. A stencil printing apparatus described in Patent Document 1 includes a plate cylinder on which a divided master-making master in which a first plate-making image and a second plate-making image are formed side by side along the rotation direction of the plate cylinder, A printing unit having pressing means that can be moved toward and away from the plate cylinder, a paper discharge unit that discharges printed paper printed by the printing unit, and a first plate-making image or a second image printed by the printing unit Corresponding to the plate-making image, the front surface printed paper on which the printed image is formed on one side is temporarily held, and then the front surface printed paper is sent out toward the pressing means and reversed by the pressing means to the printing unit. A re-feeding unit that re-feeds the paper, transport means for transporting the front-side printed paper sent from the printing unit to the re-feeding unit, and paper that has passed the printing unit to the re-feeding unit or the paper discharge unit. Switching means for guiding.

  During single-sided printing, the switching member constituting the switching unit occupies a position that does not protrude from the paper transport path so that the front-side printed paper is guided to the paper discharge unit. Switching is performed so that the switching member occupies a position protruding from the sheet conveyance path so as to guide the sheet feeding unit.

JP 2005-125716 A

  In the stencil printing apparatus capable of double-sided printing having such a configuration, the switching member switches so as to transport the surface-printed paper to the paper refeeding section or the paper discharging section. Has been placed. For this reason, since the switching member constitutes a part of the sheet conveyance path when guiding the sheet to the sheet discharge portion, the entire length thereof is increased. However, if the total length is long, when the front surface printed paper occupies a position protruding from the paper conveyance path so as to guide it to the paper refeeding section, it will be located near the outer peripheral surface of the plate cylinder, It will be in the state which blocks the ventilation from the peeling fan which peels from the plate cylinder outer peripheral surface. In such a state, the air flow for separating the paper from the plate cylinder tends to be insufficient, and the leading edge of the paper may be damaged when there is an upward curl at the leading edge of the paper or when there is a solid image at the leading edge of the paper. Peeling becomes unstable due to sticking to the plate cylinder, and there is a concern that paper jam may occur during separation. In addition, since the amount of air blown between the plate cylinder and the paper is reduced, the force to peel off the paper is insufficient, and the image surface of the surface-printed paper comes into contact with the switching member due to the peeling delay and There is concern about the occurrence of rubbing dirt.

  The present invention provides a stencil printing apparatus capable of performing double-sided printing capable of appropriately separating paper from a plate cylinder while maintaining paper transportability and suppressing smearing of an image surface due to occurrence of a jam or separation delay. That is the purpose.

  In order to achieve the above-described object, the invention according to claim 1 is a printing in which printing is performed on the front surface or both front and back surfaces of a sheet by pressing the sheet with a pressing unit against a plate-making master wound around the outer peripheral surface of the plate cylinder. Part, a peeling part for peeling the paper printed by the printing part from the outer peripheral surface of the plate cylinder, a paper discharge part for discharging the paper peeled by the peeling part, and a surface printed by the printing part and peeled by the peeling part Holding the printed surface-printed paper, and then feeding the surface-printed paper toward the pressing means, reversing the pressing means and re-feeding it toward the printing section, and passing through the printing section In the stencil printing apparatus, which has a switching means for guiding the discharged paper to the paper refeeding section or the paper discharge section and can print on both sides of the paper with one rotation of the plate cylinder, the switching means is peeled off from the outer peripheral surface of the plate cylinder. The first position for guiding the discharged paper to the paper discharge section, and the outer periphery of the plate cylinder A pair of switching members supported so as to be swingable in opposite directions so as to occupy a second position for guiding the surface-printed sheet peeled off from the sheet to the paper re-feeding section; A stencil printing apparatus comprising drive means for switching between a position and a second position.

  In the invention according to claim 2, the pair of switching members are arranged in parallel in the sheet conveying direction, and the total length of the switching member on the downstream side in the sheet conveying direction is shorter than the total length of the switching member on the upstream side in the sheet conveying direction. It is characterized by having.

  The invention according to claim 3 is characterized in that the swinging width of the switching member on the upstream side in the paper transport direction is set larger than that on the downstream side in the paper transport direction.

  According to a fourth aspect of the present invention, the drive means meshes with the first gear means and the first gear means for rotating the first support shaft provided at the swing end of the switching member on the upstream side in the sheet conveying direction. A second gear unit that decelerates and rotates a second support shaft provided at the swing end of the switching member disposed downstream of the sheet conveyance direction, and a drive motor that rotates the first gear unit or the second gear unit. It is characterized by that.

  According to the fifth aspect of the present invention, the driving means has a first end fixed to each swinging end of the switching member on the upstream side in the paper transport direction and the downstream side in the paper transport direction, and the other end forming a free end. A first link having first and second link levers, a connecting link lever pin-coupled to the free ends of the first and second link levers, and a drive member for swinging any one of the link levers; The lever is set shorter than the second link lever.

  According to the present invention, the paper that has passed through the printing unit is fed to the refeeding unit or the paper discharge unit that feeds the surface-printed paper toward the pressing unit, reverses the paper with the pressing unit, and refeeds the paper toward the printing unit. The switching means for guiding guides the sheet peeled from the outer peripheral surface of the plate cylinder to the paper discharge unit, and the second position guides the surface-printed paper peeled from the outer peripheral surface of the plate cylinder to the refeeding unit. A pair of switching members supported so as to be swingable in opposite directions so as to occupy each of the positions, and drive means for switching the pair of switching members between the first position and the second position, When occupying the first position, the length equivalent to that of the conventional switching member can be maintained, and when occupying the second position, it can be shortened by the divided amount. For this reason, when the switching member occupies the first position, the transportability can be secured, and when the switching member occupies the second position, the blowing from the peeling portion that peels the front end of the sheet from the outer peripheral surface of the plate cylinder is blocked. Therefore, the sheet can be properly separated from the plate cylinder, and the image surface can be prevented from being stained due to the occurrence of a jam or a delay in peeling.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes a stencil printing apparatus of a reverse refeed type. Since this stencil printing apparatus 1 has a configuration related to the double-sided printing apparatus disclosed in Japanese Patent Laid-Open No. 2003-200355, description of each part is omitted as much as possible.

(First embodiment)
The operation will be described together with an outline of the overall configuration of the stencil printing apparatus 1 in the present embodiment, mainly using FIG. The stencil printing apparatus 1 includes a printing unit 2, a plate making unit 3, a paper feeding unit 4, a plate discharging unit 5, a paper discharging unit 6, an image reading unit 7, a switching unit 8, a refeeding unit 9, a peeling unit 30, and a control unit 10. Etc., and is configured to be capable of performing single-sided printing that prints on the surface of the paper P with one rotation of the plate cylinder 11 and double-sided printing that prints on both sides of the paper P with one rotation of the plate cylinder 11. It is configured as a device.

  The printing unit 2 disposed almost at the center of the apparatus main body 1A of the stencil printing apparatus 1 includes a plate cylinder 11 and a press roller 12 serving as a pressing unit. The plate cylinder 11 is rotatably supported by the apparatus main body 1A and is driven to rotate by a plate cylinder driving means (not shown). The plate cylinder 11 has a clamper 13 that can be freely opened and closed on its outer peripheral surface (hereinafter referred to as “plate cylinder outer peripheral surface”) 11 a, and the master made by the plate making unit 3 on the plate cylinder outer peripheral surface 11 a during double-side printing. 14 (hereinafter referred to as “the pre-made master”) is wound.

  The master-made master 14 made by the plate-making unit 3 is wound around the plate cylinder outer peripheral surface 11a with its tip end clamped by the clamper 13. As shown in FIG. 2, the master-making master 14 includes a first image 201 for front side printing (hereinafter referred to as “front side image 201”) and a second image 202 for back side printing (hereinafter referred to as “back side image”). 202 ”) are formed side by side in the direction of rotation of the plate cylinder 11. In stencil printing, since the image is directly transferred from the master 14 to the paper P, the image on the master 14 is a mirror image. FIG. 2 is a diagram illustrating a state in which the master-made master 14 is wound around the printing drum 11 and viewed from the film surface side. An unprinted portion is formed between the front image 201 and the back image 202. The plate-making master 14 is wound on the plate cylinder 11 so that the front surface image 201 corresponds to the front surface region shown in FIG. 1, the back surface image 202 corresponds to the same back surface region, and the unfinished plate portion 204 corresponds to the same intermediate region. The

  As shown in FIG. 1, a press roller 12 is disposed below the plate cylinder 11. The press roller 12 made of an elastic material having water repellency such as fluororesin is rotatably supported at both ends by an arm member (not shown), and the arm member (not shown) is swingably supported by a swing means (not shown). ing. The press roller 12 has a plate cylinder so that its circumferential surface selectively occupies the separation position shown in FIG. 1 where the circumferential surface is separated from the plate cylinder 11 and the pressure contact position where the circumferential surface is pressed against the plate-making master 14 on the plate cylinder 11. 11 can be freely contacted and separated.

  Near the right side of the press roller 12, a refeed guide member 17 is provided for transporting the surface printed paper P <b> 1 sent from the refeed unit 9 along the peripheral surface of the press roller 12. Yes. Below the press roller 12, a re-feeding registration roller 18 is provided that sends out the surface-printed paper P <b> 1 stored on the auxiliary tray 8 in contact with the peripheral surface of the press roller 12. A refeed conveyance unit 19 having an auxiliary tray 22 on the upper surface is disposed on the lower left side of the press roller 12. A refeed positioning member 20 is integrally provided on the auxiliary tray 22. A sheet receiving plate 21 that is movable along the upper surface of the auxiliary tray 22 is disposed above the refeed conveyance unit 19. The auxiliary tray 22, the refeed guide member 17, the refeed registration roller 18, the refeed positioning member 20, the refeed conveyance unit 19, and the sheet receiving plate 21 constitute a refeed unit 9.

  A plate making unit 3 is disposed on the upper right side of the printing unit 2. The plate making section 3 is a well-known master holding member that holds a master roll obtained by winding an unprinted master into a roll, a platen roller, a thermal head, a master cutting means, a master stock section, a tension roller pair, a reverse roller pair, and the like. The plate making unit 14 creates a plate making master 14.

  A sheet feeding unit 4 is disposed below the plate making unit 3. The paper feed unit 4 is formed between the paper feed tray 48 on which the paper P is stacked, the paper feed roller 51 that feeds the paper P on the paper feed tray 48, and the paper feed tray 48 and the plate cylinder 11. A registration roller pair 53 disposed in the conveyance path is provided.

  The plate discharging unit 5 disposed on the upper left side of the printing unit 2 has a well-known configuration including an upper plate discharging member, a lower plate discharging member, a plate discharging box, a compression plate, and the like. It is a well-known configuration that is peeled off from 11a and discarded inside the plate discharging box.

  A peeling unit 30 and a paper discharge unit 6 are disposed below the plate discharge unit 5. The peeling unit 30 includes a peeling claw 31 and a peeling fan 32 that blows air between the peeling claw 31 and the plate cylinder outer peripheral surface 11a. The tip of the peeling claw 31 is provided so as to be close to and away from the plate cylinder outer peripheral surface 11a by a swing driving means (not shown), and the sheet P is peeled from the plate cylinder outer peripheral surface 11a by occupying the close position. To do. The peeling fan 32 is disposed above the peeling claw 31 and finishes printing by blowing air toward the plate cylinder outer peripheral surface 11a, and is separated from the plate cylinder outer peripheral surface 11a by the separation claw 31. Each tip P1a has a function of floating.

  The paper discharge unit 6 is disposed below the peeling unit 30 and includes a paper discharge conveyance unit 33 and a paper discharge tray 34. The paper discharge conveyance unit 33 includes a driving roller, a driven roller, an endless belt, a suction fan, and the like, and an arrow in FIG. 1 sucks the surface printed paper P1 or the front and back double-side printed paper P2 on the upper surface of the endless belt. Transport to the paper transport indicated by X. The paper discharge tray 33 has a well-known configuration having one end fence and a pair of side fences, and the front surface printed paper P1 or the front and back double-side printed paper P2 is stacked on the upper surface thereof.

  An image reading unit 7 is disposed on the upper part of the apparatus main body 1A. The image reading unit 7 includes a contact glass, a pressure plate provided so as to be able to come in contact with and away from the contact glass, a reflection mirror and a fluorescent lamp that scans and reads a document image, a lens that focuses the scanned image, and a focused image. It has an image sensor for processing and the like, and an ADF unit 61 that is an automatic document reader is provided on the upper part thereof.

  On the left side of the contact position between the plate cylinder 11 and the press roller 12 and on the transport path R of the paper P, the front surface printed paper P1 and the front and back double-side printed paper P2 that have passed through the printing section 2 are ejected. Alternatively, a switching means 8 for guiding the refeed unit 9 is provided. As shown in FIG. 5A, the switching unit 8 has a first position for guiding the front surface printed paper P1 and the front and back double side printed paper P2 separated from the plate cylinder outer peripheral surface 11a to the paper discharge unit 6. As shown in FIG. 5B, the surface-printed paper P1 peeled off from the outer peripheral surface 11a of the plate cylinder can be swung in opposite directions so as to occupy a second position for guiding the paper P1 to the refeeding section 9. And a pair of switching members 81 and 82, and driving means 83 for switching the switching members 81 and 82 between the first position and the second position.

  The switching members 81 and 82 are arranged in parallel in the paper conveyance direction X, and the total length L1 of the switching member 82 arranged on the downstream side in the paper conveyance direction is arranged on the upstream side in the paper conveyance direction. It is shorter than L2. The switching member 81 is formed so that its swing end 81a can rotate integrally with a first support shaft 89 that is swingably swingable in the illustrated frame. The switching member 82 is formed so that its swing end 82a can rotate integrally with a second support shaft 88 that is swingably supported by the illustrated frame.

  When the switching members 81 and 82 occupy the first position, the upper surfaces 81c and 82c of the switching members 81 and 82c are positioned on the same plane to form the lower part of the transport path R, and are flat surfaces so as not to protrude into the transport path R. Is formed. The back surface 82b of the switching member 82 is formed in an arcuate surface that guides the front surface printed paper P1 passing through the transport path R to the refeed unit 9 when the switching member 82 occupies the second position. Has been.

  The driving means 83 includes a gear 84 serving as a first gear means for rotating the first support shaft 89 provided at the swinging end 81 a of the switching member 81 and a second gear provided at the swinging end 82 a of the switching member 82. A gear 86 serving as second gear means for decelerating and rotating the support shaft 88, a gear 85 arranged so as to mesh with the gear 84, and a gear 85 mounted on an output shaft 87a thereof. And a drive motor 87 that rotates. The gears 84 and 85 have tooth portions having the same diameter and the same pitch, and the gear 86 has a larger diameter than the gears 84 and 85 and the number of teeth is increased. In this embodiment, the gear 85 constitutes a drive gear and the gears 84 and 86 constitute a slave gear. However, the gear 84 may be driven by the drive motor 87. In this case, the gear 84 constitutes a drive gear, the gear 86 constitutes a slave gear, and the gear 85 constitutes an idle gear. Alternatively, the gear 86 may be driven by the drive motor 87. In this case, the gear 86 constitutes a drive gear, the gear 84 constitutes a slave gear, and the gear 85 constitutes an idle gear. As the drive motor 87, a stepping motor is used so as to rotate forward and backward.

  In the present embodiment, when the switching member 81 moves from the first position to the second position, the upper surface 81c is bent so as to be positioned below the transport path R as shown in FIG. It is swung by the driving means 83 in the clockwise direction. When the switching member 82 moves from the first position to the second position, the switching member 82 is swung by the driving means 83 in the clockwise direction so that the back surface 81b occupies a position that protrudes and blocks the inside of the transport path R.

  That is, when moving the switching members 81 and 82 from the first position to the second position, the drive motor 87 rotates the gear 85 in the clockwise direction indicated by the arrow a as shown in FIG. When driving and moving the switching members 81 and 82 from the second position to the first position, the gear 85 is rotationally driven in the counterclockwise direction indicated by the arrow b as shown in FIG. 5B. The angles θ1 and θ2 that are the swinging widths of the switching member 81 and the switching member 82 are set so that the swinging angle θ1 of the switching member 81 is larger than the swinging angle θ2 of the switching member 82. The initial position of the switching members 81 and 82 is the first position.

  FIG. 3 shows the operation panel of the duplex printing apparatus 1. In the figure, the operation panel 15 is pressed to perform a plate making start key 35, a printing start key 36, a stop key 37, a numeric keypad 38, a display device 39 consisting of a 7-segment LED, a display device 40 consisting of an LCD, and one-side printing. A well-known configuration such as a single-sided printing key 41 and a double-sided printing key 42 that is pressed when performing double-sided printing is provided.

  FIG. 4 is a block diagram of the control means 10 used in the stencil printing apparatus 1. In the figure, the control means 10 is composed of a well-known computer having a CPU, ROM, RAM, etc., and based on the operation signal from the operation panel 15 and the detection signal from each sensor, the printing unit 2, plate making unit 3, Each of the drive means of the paper feed unit 4, the plate discharge unit 5, the paper discharge unit 6, the image reading unit 7, the re-feed unit 9, and the peeling unit 30 and the operation of the drive motor 87 serving as the drive unit of the switching unit 8 are controlled To do. The ROM stores an operation program of the stencil printing apparatus 1, and the RAM temporarily stores various numerical values, information, and the like. The CPU stores the numerical values and information stored in the RAM and the operations called from the ROM. The operation of the stencil printing apparatus 1 is controlled based on the program. In this embodiment, the control means 10 operates the drive motor 87 so that the switching members 81 and 82 occupy the second position at the time of double-sided printing and the first position at the time of printing on the back side. Control.

  The single-sided printing and double-sided printing of the stencil printing apparatus 1 and the operation of the switching means 8 at that time will be described.

  In this embodiment, single-sided printing means that the master 14 on which an image for single-sided printing is made within the length of one plate by the plate making unit 3 is wound around the plate cylinder outer peripheral surface 11 a and is contacted and separated from the plate cylinder 11. The paper P is pressed against the plate cylinder 11 by a free press roller 12 and printed on one side thereof.

In the present embodiment, double-sided printing refers to winding the master 14 in which the first image 201 and the second image 202 are arranged side by side within the length of one plate by the plate making unit 3 around the plate cylinder outer peripheral surface 11a, The press roller 12 presses the paper P against the plate cylinder 11 to print on the front surface, and the front-side printed paper P1 is fed again from the refeed unit 9 to the printing unit 2 and printed on the back surface thereof. .
(Single-sided printing and operation of switching means)
A single-sided printing mode is set by setting a document on the image reading unit 7 or the ADF 61, pressing the single-sided printing key 41, and pressing the plate making start key 35. When the single-sided printing mode is set, the plate making unit 3 is operated after the plate discharging unit 5 is operated and the plate discharging operation is performed, and the plate making operation is performed, and the plate making master 14 is wound around the plate cylinder outer peripheral surface 11a. The At this time, one sheet P for printing is fed from the sheet feeding unit 4 and a printing operation is performed to enter a single-sided printing standby state.

  When the print start key 36 is pressed after the number of printed sheets is set by the ten key 38, the sheet P is continuously fed from the sheet feeding unit 4 and the one-side printing operation is performed. Here, the plate cylinder 11 rotates at the printing speed, and the sheet P is fed toward the printing unit 2 by the registration roller pair 53 in accordance with the rotation timing, and the press roller 12 is raised to the plate cylinder outer peripheral surface 11a. By being pressed, the plate-making image of the plate-making master 14 is transferred.

  At this time, in the separation unit 30, as shown in FIG. 6A, the tip of the peeling claw 31 is placed at a position close to the plate cylinder outer peripheral surface 11a by the swing driving means, and the peeling fan 32 is operated. Air is sent between the separation claw 31 and the plate cylinder outer peripheral surface 11a. At this time, since the drive motor 87 is not driven, the switching members 81 and 82 remain in the first position.

Therefore, the sheet-transferred sheet P1, that is, the surface-printed sheet P1, is separated from the plate cylinder outer peripheral surface 11a by the function of the separating unit 30, and the leading end P1a falls on the upper surface 81c of the switching member 81, As shown in FIG. 1, the paper is guided to the paper discharge conveyance unit 32 on the downstream side in the paper conveyance direction, and is discharged onto the paper discharge tray 33 by the paper discharge conveyance unit 32. Such single-sided printing operation is continued until the set number of prints is reached. When the set number of prints is reached, the single-sided printing operation is completed, and the duplex printing apparatus 1 enters the single-sided printing standby state again.
(Double-sided printing and operation of switching means)
After the original is set in the image reading unit 7 and the duplex printing key 41 is pressed, the plate making start key 35 is pressed to set the duplex printing mode. After the plate discharging unit 5 is operated and the plate discharging operation is performed, the plate making is performed. The plate making operation is performed by the operation of the section 3, and the pre-made master 14 is wound around the outer periphery 11a of the plate cylinder. In addition, one sheet P for sheet printing is fed from the sheet feeding unit 4 and a plate printing operation is performed, so that both sides are in a standby state.

  When the print start key 36 is pressed after the number of prints is set by the ten key 38, the paper P is continuously fed from the paper supply unit 4 and the double-sided printing operation is performed. Here, the plate cylinder 11 rotates at the printing speed, and one sheet P is fed toward the printing unit 2 by the registration roller pair 53 in accordance with the rotation timing. Only the plate cylinder outer peripheral surface 11a is pressed. Then, the first image 201 of the master-made master 14 is transferred to the surface of the paper P.

  At this time, in the separation unit 30, as shown in FIG. 6B, the tip of the peeling claw 31 is placed at a position close to the plate cylinder outer peripheral surface 11a by the swing driving means, and the peeling fan 32 is operated. Since the air is sent between the separation claw 31 and the plate cylinder outer peripheral surface 11 a, the paper on which the first image 201 is transferred, that is, the surface-printed paper P 1 is peeled from the plate cylinder outer peripheral surface 11 a by the function of the separation unit 30. At the same time, the drive motor 87 operates in the forward rotation direction, and the switching members 81 and 82 move from the first position shown in FIG. 6A to the second position shown in FIG. 6B.

  For this reason, since the conveyance path R formed between the printing unit 2 and the paper discharge conveyance unit 32 is opened, the surface printed paper P1 separated from the plate cylinder outer peripheral surface 11a is re-feeded from the conveyance path R. 9 is guided to the paper re-feeding section 9 via the transport route R1 connected to the paper 9.

  Further, when the switching member 82 occupies the second position, it occupies a position that obstructs the conveyance path R, and its back surface 82b is directed to the printing unit 2 side, so that the printed surface is separated as shown in FIG. Even when the sheet P1 is not separated well by the separating unit 30 and advances straight, the sheet leading end P1a collides with the back surface 82b and is returned to the transport path R1 by the curved surface of the back surface 82b, so that the sheet refeeding unit You will be guided to 9.

  The front printed sheet P1 guided to the refeed unit 9 is fed from the refeed unit 9 and printed so as to be in time with the back surface area of the plate cylinder 11 in the printing unit 2 as shown in FIG. The second image 202 is transferred to the back side that is not. Here, the drive motor 87 operates in the reverse direction, and the switching members 81 and 82 move from the second position shown in FIG. 6B to the first position shown in FIG.

  For this reason, since the released conveyance path R is closed during single-sided printing, the sheet on which the second image 202 is transferred, that is, the sheet P2 printed on the front and back sides, is separated from the plate cylinder outer peripheral surface 11a by the function of the separating unit 30. The tip P2a is peeled off and falls onto the upper surface 81c of the switching member 81, and is guided to the paper discharge conveyance unit 32 on the downstream side in the paper conveyance direction as shown in FIG. The paper is discharged onto the paper discharge tray 33 by the transport unit 32. Such a double-sided printing operation is continued until the set number of printed sheets is reached, and when the set number of printed sheets is reached, the double-sided printing operation is completed, and the double-sided printing apparatus 1 enters the double-sided printing standby state again.

  According to such a configuration, the re-feeding unit 9 or the paper discharge unit 6 that feeds the surface-printed paper P1 toward the press roller 12, reverses the paper with the press roller 12, and re-feeds the paper toward the printing unit 2, The switching means 8 for guiding the front-side printed paper P1 or the front-back double-side printed paper P2 that has passed through the printing unit 2 discharges the front-side printed paper P1 and the front-back double-side printed paper P2 that have been peeled from the plate cylinder outer peripheral surface 11a. The first position for guiding to the section 6 and the second position for guiding the surface-printed sheet P1 peeled off from the outer peripheral surface 11a of the plate cylinder to the refeed section 9 can swing in opposite directions. And a driving means 83 for switching the switching members 81 and 82 between the first position and the second position, so that the switching members 81 and 82 are the first switching member 81 and 82. When occupying position Can maintain the length equivalent to the conventional switching member, when occupying a second position, it can be shortened only divided min. For this reason, when the switching members 81 and 82 occupy the first position, the transportability can be ensured, and when the switching members 81 and 82 occupy the second position, the peeling portion 30 that peels the paper leading edge P1a from the plate cylinder outer peripheral surface 11a. Therefore, it is possible to appropriately isolate the surface-printed paper P1 from the plate cylinder 11, and to suppress the image surface contamination due to the occurrence of a jam or a peeling delay.

  In this embodiment, the switching members 81 and 82 are arranged in parallel in the paper transport direction, and the total length L1 of the switching member 82 on the downstream side in the paper transport direction is formed shorter than the total length L2 of the switching member 81 on the upstream side in the paper transport direction. Therefore, when the switching member 82 occupies the second position, the amount of protrusion from the transport path R can be made lower than that in the conventional configuration, and the air blown from the peeling portion 30 is not blocked more. The surface-printed paper P1 can be more appropriately isolated from the cylinder 11, and the image surface can be further prevented from being soiled due to the occurrence of a jam or a delay in peeling.

According to this embodiment, since the swing angle θ1 of the switching member 81 on the upstream side in the paper transport direction is set larger than the swing angle θ2 of the switching member 82 on the downstream side in the paper transport direction, the transport path R is greatly opened. The surface-printed paper P1 separated from the plate cylinder 11 can be guided more smoothly to the paper re-feed unit 9, and the occurrence of jam can be reduced, and the paper P1 is positioned downstream in the paper transport direction. A sufficient distance between the switching member 82 and the surface printed paper P1 can be ensured, and the occurrence of image surface contamination due to the contact between the switching member 82 and the surface printed paper P1 can be further reduced.
(Second Embodiment)
In the present embodiment, as shown in FIGS. 7 to 9, the switching means 8 </ b> A is configured with the configuration of the driving means 8 in the first embodiment as the driving means 180. For this reason, since the structure of the switching members 81 and 82 is the same as that of 1st Embodiment, it demonstrates centering on a different structure from 1st Embodiment.

  In the driving means 180, first and second link levers having one ends 181a and 182a fixed to the swinging ends 81a and 82a of the switching members 81 and 82 and the other ends 181b and 182b forming free ends, respectively. 181, 182, a connection link lever 183 that is pin-coupled to the free ends of the first and second link levers 181, 182, and an electromagnetic solenoid 184 that serves as a drive member that swings the second link lever 182. ing.

  The first link lever 181 has a shorter overall length than the second link lever 182. Each of the link levers 181 and 182 hangs substantially vertically around the support shafts 89 and 88 when the switching members 81 and 82 occupy the first position shown in FIG. When 81 and 82 occupy the second position shown in FIG. 7B, they are configured to swing counterclockwise around the support shafts 88 and 89. Further, the swing angle θ4 between the first position and the second position around the support shaft 89 of the first link lever 181 is the swing angle θ4 of the second link lever 182 around the support shaft 88. It is set to be larger than the moving angle θ3.

  The electromagnetic solenoid 184 includes a main body 184 a and a movable rod 184 b, and the distal end of the movable rod 184 b is pin-coupled near the other end 182 b of the second link lever 182. As shown in FIG. 8, the movable rod 184b is connected to the control means 10A of the stencil printing apparatus 1 via a signal line. The control means 10A is turned off during single-sided printing, and controls the electromagnetic solenoid 182 to operate so as to push the movable rod 184b as shown in FIG. 7B during front-side printing during double-sided printing.

  According to the switching means 8A provided with the driving means 182 having such a configuration, the electromagnetic solenoid 182 does not operate during single-sided printing, so that the switching members 81 and 82 remain in the first position. For this reason, the surface-printed paper P1 is peeled off from the plate cylinder outer peripheral surface 11a by the function of the separating section 30, and the leading end P1a falls on the upper surface 81c of the switching member 81, and passes through the upper surface 82c of the switching member 82, as shown in FIG. As shown in FIG. 3, the paper is guided to the paper discharge conveyance unit 32 on the downstream side in the paper conveyance direction, and is discharged to the paper discharge tray 33 by the paper discharge conveyance unit 32. Such single-sided printing operation is continued until the set number of prints is reached. When the set number of prints is reached, the single-sided printing operation is completed, and the duplex printing apparatus 1 enters the single-sided printing standby state again.

  On the other hand, since the electromagnetic solenoid 182 is actuated at the time of front side printing at the time of duplex printing, the switching members 81 and 82 move from the first position shown in FIG. 7A to the second position shown in FIG. 7B. To do. For this reason, since the conveyance path R formed between the printing unit 2 and the paper discharge conveyance unit 32 is opened, the surface printed paper P1 separated from the plate cylinder outer peripheral surface 11a is re-feeded from the conveyance path R. 9 is guided to the paper re-feeding section 9 via the transport route R1 connected to the paper 9.

  When the switching member 82 occupies the second position, it occupies a position that blocks the conveyance path R, and the back surface 82b faces the printing unit 2 side. Therefore, the front surface printed paper P1 separated as shown in FIG. However, even when the separation unit 30 does not separate well by the separation unit 30 and advances straight, the sheet front end P1a collides with the back surface 82b and is returned to the transport path R1 by the curved surface of the back surface 82b to the refeed unit 9. It is guided.

  The front printed sheet P1 guided to the refeed unit 9 is fed from the refeed unit 9 and printed so as to be in time with the back surface area of the plate cylinder 11 in the printing unit 2 as shown in FIG. The second image 202 is transferred to the back side that is not. Here, when the operation of the electromagnetic solenoid 182 stops, the switching members 81 and 82 move from the second position shown in FIG. 7B to the first position shown in FIG.

  For this reason, since the released conveyance path R is closed during single-sided printing, the sheet on which the second image 202 is transferred, that is, the sheet P2 printed on the front and back sides, is separated from the plate cylinder outer peripheral surface 11a by the function of the separating unit 30. The tip P2a is peeled off and falls onto the upper surface 81c of the switching member 81, and is guided to the paper discharge conveyance unit 32 on the downstream side in the paper conveyance direction as shown in FIG. The paper is discharged onto the paper discharge tray 33 by the transport unit 32. Such a double-sided printing operation is continued until the set number of printed sheets is reached, and when the set number of printed sheets is reached, the double-sided printing operation is completed, and the double-sided printing apparatus 1 enters the double-sided printing standby state again. Even in such a form, the same effect as the first embodiment can be obtained.

1 is a schematic configuration diagram of a stencil printing apparatus capable of duplex printing according to the present invention. It is an outline top view showing the state where the 1st picture and the 2nd picture were made on the master. It is an enlarged view showing one form of an operation unit of the printing apparatus. It is a block diagram of the control system in the 1st Embodiment of this invention. (A) is an enlarged view showing the configuration of the switching means and the first position of the switching member in the first embodiment, and (b) is an enlarged view showing the second position of the switching member. (A) is an enlarged view showing the function of the switching member occupying the first position, (b) is an enlarged view showing the function of the switching member occupying the second position, and (c) occupies the second position. It is an enlarged view which shows another function of the changed switching member. (A) is an enlarged view showing the configuration of the switching means and the first position of the switching member in the second embodiment, and (b) is an enlarged view showing the second position of the switching member. It is a block diagram of the control system in the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stencil printing apparatus 2 Printing part 6 Paper discharge part 8,8A Switching means 9 Refeeding part 11a Plate cylinder outer peripheral surface 12 Pressing means 14 Pre-made master 18,180 Driving means 30 Peeling part 81,82 A pair of switching members 81a, 82a Swing end of switching member 83 Drive means 84 First gear means 85, 86 Second gear means 87 Drive motor 88 Second support shaft 89 First support shaft 181, 182 First and second link levers 181 a, 182a One end of the link lever 181b, 182b One end of the link lever 183 Connection link lever 184 Drive member P Paper P1 Front printed paper X Paper transport direction L1 Total length of the switching member on the downstream side of the paper transport direction L2 Switching member on the upstream side of the paper transport direction Total length of θ1-θ4 Swing width of switching member

Claims (5)

A printing unit that performs printing on the front surface or both front and back surfaces of the paper by pressing the paper with a pressing means against a pre-printed master wound around the outer peripheral surface of the plate cylinder, and the paper printed by the printing unit on the plate cylinder A peeling part that peels off from the outer peripheral surface, a paper discharge part that discharges the paper peeled off at the peeling part, and a surface printed paper that is printed on the surface of the printing part and peeled off by the peeling part, A sheet re-feeding unit that feeds the surface-printed sheet toward the pressing unit, reverses the sheet with the pressing unit, and re-feeds the sheet toward the printing unit; and a sheet re-feeding unit that passes the printing unit Or a stencil printing apparatus capable of printing on both sides of a sheet of paper by one rotation of the plate cylinder.
The switching means is
A first position for guiding the sheet peeled from the outer peripheral surface of the plate cylinder to the paper discharge unit, and a second position for guiding the surface printed sheet peeled from the outer peripheral surface of the plate cylinder to the refeeding unit. A pair of switching members supported so as to be swingable in opposite directions so as to occupy the position;
A stencil printing apparatus comprising drive means for switching the pair of switching members between a first position and a second position.   The pair of switching members are arranged in parallel in the paper transport direction, and the total length of the switching member on the downstream side in the paper transport direction is shorter than the total length of the switching member on the upstream side in the paper transport direction. The stencil printing apparatus according to claim 1.   3. The stencil printing apparatus according to claim 1, wherein a swinging width of the switching member on the upstream side in the paper conveyance direction is set larger than that on the downstream side in the paper conveyance direction.   The drive means is disposed to mesh with the first gear means for rotating the first support shaft provided at the swing end of the switching member on the upstream side in the paper conveyance direction, and to engage the paper conveyance And a second gear means for decelerating and rotating a second support shaft provided at the swing end of the switching member on the downstream side in the direction, and a drive motor for rotating the first gear means or the second gear means. The stencil printing apparatus according to claim 2 or 3. The driving means has first and second links whose one ends are fixed to the swinging ends of the switching members on the upstream side in the paper transport direction and on the downstream side in the paper transport direction, and the other ends form free ends. A lever, a connecting link lever pin-coupled to the free ends of the first and second link levers, and a drive member for swinging any one of the link levers;
4. The stencil printing apparatus according to claim 2, wherein the first link lever is set shorter than the second link lever.

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