JP2011143618A - Stencil printing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent clogging of a paper sheet when printing with a first drum and not printing with a second drum, in a stencil printing apparatus including the first and second drums. <P>SOLUTION: The stencil printing apparatus 1 includes a first stencil printing part 3, a second stencil printing part 4, an intermediate conveying part 5 and a control part 7. The second stencil printing part 4 includes a printing drum 41, and second press roller 42 feeding a paper sheet P by pressing it to the printing drum 41 when printing and forming a gap between the printing drum 41 and itself in a non-printing time. The control part 7 controls the conveying speed of the intermediate conveying part 5 so that the speed of the paper sheet P passing through the gap is faster than the feeding speed by the second stencil printing part 4 when also printing is performed with the second stencil printing part 4, when printing is performed with first stencil printing part 3 and not performed with the second stencil printing part 4. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a stencil printing apparatus. More specifically, the present invention relates to a stencil printing apparatus capable of printing a sheet with two drums.

  In recent years, the first drum and the second drum are arranged adjacent to each other, the paper is printed by the first drum, the paper printed by the intermediate transport unit is transported to the second drum, and the transported paper is transported by the second drum. 2. Description of the Related Art A stencil printing apparatus that prints and discharges paper by a paper discharge conveyance unit is known.

  In such a stencil printing apparatus, in order to transfer ink, a sheet is pressed against a drum by a press roller, the sheet is sandwiched between the drum and the press roller, and is sent out while printing the sheet by rotating the drum.

  In such a stencil printing apparatus, there is a possibility that the timing at which the paper is peeled from the first drum varies depending on the amount of ink transferred from the first drum, that is, the timing at which the paper is fed to the intermediate transport unit may vary. As a result, the timing of starting the sheet conveyance by the intermediate conveyance unit is deviated, and there is a possibility that the printing position deviation in the second drum may occur.

  In Patent Document 1, in order to adjust the shift in the timing of starting the sheet conveyance of the intermediate conveyance unit and to adjust the printing position on the second drum, the conveyance speed of the intermediate conveyance unit is made faster than the delivery speed of the first drum. A stencil printing apparatus has been proposed.

Patent 4138045

  However, in such a stencil printing apparatus, when printing is performed with the first drum but not with the second drum, the second press roller of the second drum is separated from the second drum as shown in FIG. Since the sheet is not pressed toward the second drum, the sheet passes through the gap between the second drum and the second press roller and is conveyed to the sheet discharge conveyance unit.

  As described above, when printing is not performed by the second drum, the intermediate transport unit needs to transport the sheet to the paper discharge transport unit in an unstable state in which the second drum and the second press roller are not pinched.

  The technique described in Patent Document 1 does not consider the case where printing is performed with the first drum and printing is not performed with the second drum as described above.

  If the intermediate transport unit cannot reliably transport the paper to the paper discharge transport unit, there is a possibility that paper jam occurs before the paper discharge transport unit.

  SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a stencil printing apparatus capable of avoiding a paper jam even when printing is performed using the first drum and not printing using the second drum in the stencil printing apparatus including the first and second drums. Providing equipment.

  In order to solve the above problems, a stencil printing apparatus according to the present invention includes a first stencil printing unit, a second stencil printing unit, and an intermediate for transporting paper printed by the first stencil printing unit to a second stencil printing unit. In a stencil printing apparatus provided with a transport unit and a control unit for controlling the transport speed of the intermediate transport unit, the second stencil printing unit is a rotationally driven printing drum, and at the time of printing, a sheet close to the printing drum. And a driven press roller that rotates with the printing drum and feeds out the paper, and away from the printing drum to form a gap with the printing drum at the time of non-printing. When the paper is printed by the first stencil printing unit and not printed by the second stencil printing unit, the second stencil printing unit when the speed of the paper passing through the gap in the second stencil printing unit is printed by the second stencil printing unit. Feeding speed by As it will be large, and controlling the conveying speed.

  Here, “the speed of the sheet passing through the gap” means the speed of the sheet until the leading edge of the sheet passing through the gap reaches the paper discharge transport unit.

  Further, the stencil printing apparatus of the present invention includes a paper length acquisition unit that acquires a length in the conveyance direction of the paper, and the control unit has a length of the paper between the first stencil printing unit and the second stencil printing unit. It may be determined whether the distance is shorter than the distance between them.

  Here, the “distance between the first stencil printing unit and the second stencil printing unit” means the distance between the printing position in the first stencil printing unit and the printing position in the second stencil printing unit. This printing position means a position where each press roller presses the paper toward each printing drum.

  In the stencil printing apparatus of the present invention, even if the printing drum of the second printing unit is interlocked with the printing drum of the first printing unit and rotates at the same rotational speed as the printing drum of the first printing unit. Good.

  According to the present invention, the stencil printing apparatus includes a first stencil printing unit, a second stencil printing unit, an intermediate transport unit that transports the paper printed by the first stencil printing unit to the second stencil printing unit, A control unit that controls the conveyance speed of the intermediate conveyance unit, and the second stencil printing unit rotates the printing drum, and presses the sheet toward the printing drum in the vicinity of the printing drum at the time of printing. And a driven press roller that is spaced apart from the printing drum and forms a gap with the drum when not printing, and the control unit prints the paper with the first stencil printing unit and prints the second stencil printing plate. When printing is not performed in the printing unit, the conveyance speed is controlled so that the speed of the paper passing through the gap in the second stencil printing unit is larger than the feeding speed of the second printing unit when printing in the second stencil printing unit. By the second hole When the intermediate conveying unit prints even at the second stencil printing unit even when the distance at which the paper is not supported by the printing unit is longer than the printing at the second stencil printing unit. Since the paper is carried out so that it can pass through the gap at a speed higher than that, the paper can surely reach the paper discharge transport unit, and the occurrence of paper jam in front of the paper discharge transport unit can be avoided. .

Configuration diagram of stencil printing machine The figure which shows the transition of the paper which is printed in the 1st stencil printing part and is not printed in the 2nd stencil printing part The figure which shows the state of the paper which prints in the 1st stencil printing part and does not print in the 2nd stencil printing part

  Hereinafter, embodiments of the stencil printing apparatus of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a configuration diagram of a stencil printing apparatus 1 which is an embodiment of the stencil printing apparatus of the present invention.

  The stencil printing apparatus 1 includes two stencil printing units. The paper P is fed to one stencil printing unit for printing, the printed paper P is intermediately conveyed, and the paper P is re-transferred to the other stencil printing unit. Paper is fed and printed, and then delivered and conveyed. In the present embodiment, the stencil printing apparatus 1 will be described as a stencil printing apparatus that prints the same surface of the paper P. However, the present invention is not limited to this. Thus, a double-sided stencil printing apparatus capable of printing on the other side of the paper P may be used.

  The configuration of the stencil printing apparatus 1 will be described. The stencil printing apparatus 1 includes a paper feeding unit 2 that feeds the paper P, a first stencil printing unit 3 that prints the fed paper P, and a second paper that prints the re-feeded paper P as necessary. A two-stencil printing unit 4, an intermediate conveyance unit 5 that refeeds the paper P to the second stencil printing unit 4 as necessary, a paper discharge unit 6 that discharges the paper P, and a control unit 7 that controls each unit. It consists of.

  The paper feeding unit 2 feeds the paper P to the first stencil printing unit 3.

  The configuration of the paper feeding unit 2 will be described. The paper feeding unit 2 is provided on the side surface of the main body 11 of the stencil printing apparatus 1, and includes a paper feeding base 21 on which the paper P is stacked, a paper feeding roller 22 that takes out the paper P one by one from the paper feeding base 21, The paper roller 23 includes a timing roller pair 24 for feeding the paper P to the first stencil printing unit 3 and a paper length detection switch 25 for detecting the length of the paper P to be fed.

  The operation of the paper feed unit 2 will be described. The paper feed unit 2 takes out the paper P1 stacked on the paper feed tray 21 by the paper feed roller 22 and the paper rolling roller 23, and sends it to the first stencil printing unit 3 by a timing roller pair 24 at a predetermined timing. The paper length detection switch 25 detects the length of the paper P fed to the first stencil printing unit 3. The paper length detection switch 25 detects the length in which the paper P is fed, that is, the length in the direction in which the paper P is conveyed in the stencil printing apparatus 1.

  The first stencil printing unit 3 prints the fed paper P.

  The configuration of the first stencil printing unit 3 will be described. The first stencil printing unit 3 is printed by the first stencil printing unit 3, the first drum 31 around which the base paper M is wound, the first press roller 32 that can reciprocate so as to be close to and away from the first drum 31, and the first stencil printing unit 3. Separation claw 33 for separating the paper P from the base paper M, a timing belt 34 for transmitting a driving force to the rotating shaft 31b of the first drum 31, a drive motor 35 for driving the first drum 31, It comprises an encoder 36 that outputs rotation information and a reference sensor 37 that detects the reference position of the first drum 31.

  The first drum 31 incorporates an ink supply roller (not shown) and has an ink-permeable peripheral wall 31a around which the base paper M is wound.

  During printing, the first press roller 32 presses the paper P toward the first drum 31 at a predetermined first pressing position in the vicinity of the first drum 31, and sandwiches the paper P 2 with the first drum 31. The first drum 31 is driven to rotate, and when not printing, a gap is formed between the first drum 31 and the first drum 31.

  The operation of the first stencil printing unit 3 will be described. The first stencil printing unit 3 rotates the drive motor 35 by the control unit 7 and rotates the first drum 31 around the rotation shaft 31 b at a predetermined speed via the timing belt 34. The first stencil printing unit 3 outputs the reference signal of the first drum 31 by the reference sensor 37 and the rotation signal of the drive motor 35 by the encoder 36 to the control unit 7 while the first drum 31 is rotating. Specifically, the encoder 36 outputs 2933 pulses per rotation of the first drum 31.

  When the first drum 31 is rotated, the base paper M is supplied and wound around the peripheral wall 31a. When the paper P is fed, the first press roller 32 approaches the first drum 31, presses the paper P toward the first drum 31 at a predetermined first pressing position, and between the first drum 31. Print while pinching. The separation claw 33 separates the paper P from the base paper M, and the first press roller 32 driven by the first drum 31 and the first drum 31 rotates to feed the paper P to the intermediate transport unit 5.

  In the present embodiment, the first stencil printing unit 3 in the stencil printing apparatus 1 is described as necessarily printing the paper P. Therefore, the description of the operation when the first stencil printing unit 3 does not print the paper P is omitted. To do. The operation when the first stencil printing unit 3 does not print the paper P is the same as the operation at the second stencil printing unit 4 described later.

  The second stencil printing unit 4 prints the re-feeded paper P as necessary.

  The second stencil printing unit 4 includes a second drum 41 that is the same as the first drum 31 by a timing belt 44 that spans between the rotation shaft 31b of the first drum 31 and the rotation shaft 41b of the second drum 41. The first stencil printing unit 3 is different from the first stencil printing unit 3 in that it is rotated at a speed and is not provided with a drive motor, an encoder, and a reference sensor. Omitted. Although the rotation speed is the same as that of the first drum 31 and the second drum 41, the difference in angle between the first drum 31 and the second drum 41, that is, the phase difference between the drums can be adjusted as necessary. . The second stencil printing unit 4 is not limited to the one that rotates the second drum 41 following the first stencil printing unit 3, and the second stencil printing unit 4 independently rotates the second drum 41. Also good.

  The operation of the second stencil printing unit 4 will be described. The operation when the second stencil printing unit 4 prints the re-feed paper P is substantially the same as that of the first stencil printing unit 3, and the description thereof is omitted.

  The operation when the second stencil printing unit 4 does not print the re-feeded paper P will be described. When the second stencil printing unit 4 does not print the re-feed paper P, the second press roller 42 is spaced from the second drum 41 to form a gap with the second drum 41, and this gap The paper P that has been re-feeded is passed. That is, when not printing, the second stencil printing unit 4 does not sandwich the re-feed paper P between the second drum 41 and the second press roller 42.

  The intermediate transport unit 5 refeeds the paper P to the second stencil printing unit 4.

  The configuration of the intermediate transport unit 5 will be described. The intermediate transport unit 5 includes a drive pulley 51, a driven pulley 52 disposed at a predetermined interval from the drive pulley 51, an annular belt 53 stretched between the drive pulley 51 and the driven pulley 52, and a suction fan. 54, a timing belt 55 for transmitting a driving force to the drive pulley 51, a drive motor 56 for rotating the drive pulley 51 via the timing belt 55, an encoder 57 for outputting rotation information of the drive motor 56, and an annular belt 53 And a paper detection sensor 58 for detecting the upper paper P.

  A plurality of through holes (not shown) are formed in the annular belt 53. As shown in FIG. 1, the suction fan 54 sucks from the back side of the annular belt 53 and generates a suction force in the through holes (not shown). . In addition, the paper detection sensor 58 is disposed substantially at the center of the annular belt 53.

  The operation of the intermediate transport unit 5 will be described. The intermediate transport unit 5 rotates the drive motor 56 by the control unit 7 and rotates the drive pulley 51 via the timing belt 55 to transport the paper P2 to the second stencil printing unit 4 at a predetermined speed. The intermediate conveyance unit 5 sucks and conveys the paper P sent out from the first stencil printing unit 3 on the annular belt 53. The intermediate conveyance unit 5 outputs the presence / absence signal of the paper P by the paper detection sensor 58 and the rotation signal of the drive motor 56 by the encoder 57 to the control unit 7 during conveyance.

  The paper discharge unit 6 discharges the paper P.

  The configuration of the paper discharge unit 6 will be described. The paper discharge unit 6 includes a paper discharge conveyance unit 61 that conveys the paper P sent out from the second stencil printing unit 4 or the paper P that has passed between the second drum 41 and the second press roller 42, and the main body 11. And a paper discharge tray 62 on which sheets P are stacked. The paper discharge conveyance unit 61 includes a driving roller 61a, a driven roller 61b, a conveyance belt 61c, and a suction fan 61d.

  The operation of the paper discharge unit 6 will be described. When the paper P sent out from the second stencil printing unit 4 or the paper P passing between the second drum 41 and the second press roller 42 is supplied onto the transport belt 61c, the paper discharge unit 6 sucks the paper P. The sheet P is sucked and conveyed by the fan 61d and stacked on the sheet discharge table 62. The control unit 7 causes the paper discharge transport unit 61 to transport the paper P at the same speed as the intermediate transport unit 5.

  The control unit 7 controls each unit.

  The control unit 7 detects the reference position of the first drum 31 based on the reference signal of the first drum 31 by the reference sensor 37 of the first stencil printing unit 3 and the rotation signal of the drive motor 35 by the encoder 36, and the first drum The current angle and speed of the first drum 31 and the second drum 41 are calculated, and control is performed so that the speed of the first drum 31 and the second drum 41 becomes a predetermined speed.

  Specifically, the control unit 7 can control the rotation speeds of the first drum 31 and the second drum 41 in stages of 30 rpm, 60 rpm, 80 rpm, 100 rpm, 110 rpm, 120 rpm, and 150 rpm. The feeding speed of the paper P at each stage is 271.4 mm / sec, 542.9 mm / sec, 723.8 mm / sec, 904.8 mm / sec, 993.5 mm / sec, 1085.7 mm / sec and 1357. 1 mm / sec.

  The control unit 7 calculates the transport distance and transport speed of the intermediate transport unit 5 based on the presence / absence signal of the paper P by the paper detection sensor 58 of the intermediate transport unit 5 and the rotation signal of the drive motor 56 by the encoder 57, and the intermediate transport unit 5 is controlled so as to be a predetermined speed.

  When the second stencil printing unit 4 prints the re-feeded paper P in the stencil printing apparatus 1, the control unit 7 controls the paper P by the second stencil printing unit 4 according to the rotational speed of each stage described above. The conveyance speed of the intermediate conveyance unit 5 is controlled so that the printing position does not shift.

  When the second stencil printing unit 4 does not print the re-feeded paper P in the stencil printing apparatus 1, that is, the second stencil printing unit 4 uses the second drum 41 and the second press roller to re-feed the paper P. In the case of passing through the gap between the second stencil printing unit 4 and the control unit 7, the speed of the paper P passing through the gap is re-feeded by the second stencil printing unit 4 according to the rotational speed of each step. When the printed paper P is printed, the speed of the intermediate transport unit 5 is controlled to be higher than the speed at which the paper P is sent out. Here, the speed of the paper P passing through the gap is the speed until the leading edge of the paper P reaches the paper discharge transport unit 61 of the paper discharge unit 6.

  The paper P carried out from the intermediate transport unit 5 has a higher speed when passing through the gap than a speed when it is sent out by the second stencil printing unit 4, so that the paper P is not pinched by the second stencil printing unit 4. Even when the distance at which P is not supported is longer than when the second stencil printing unit 4 prints, the paper reaches the paper discharge conveyance unit 61.

  Further, the control unit 7 determines that the length in the transport direction of the paper P is determined by the paper length detection sensor 25 from the distance between the first pressing position of the first stencil printing unit 3 and the second pressing position of the second stencil printing unit. To determine whether it is too short.

  When the length of the paper P in the transport direction is shorter than the distance between the first pressing position of the first stencil printing unit 3 and the second pressing position of the second stencil printing unit 4, the paper P is printed with the first stencil printing. In order to start the passage of the gap in the state where the portion 3 is not clamped, the speed of the paper P is not related to the feed speed of the first stencil printing unit 3 until the leading edge reaches the paper discharge transport unit 61. It is determined only by the transport speed of the intermediate transport unit 5. That is, since the leading end of the sheet P is unloaded from the annular belt 53 and the rear end of the sheet P is not pinched by the first stencil printing unit 3 at the time when the passage of the gap is started, the intermediate transport unit 5 accelerates the sheet P. At this time, there is no limitation for balancing with the delivery speed of the first stencil printing unit 3. Accordingly, the intermediate transport unit 5 can accelerate the paper P from the time when the passage of the gap is started, and can more reliably cause the paper P to reach the paper discharge transport unit 61.

  Specifically, the control unit 7 prints the paper P, which is shorter than the distance between the first pressing position of the first stencil printing unit 3 and the second pressing position of the second stencil printing unit, by the first stencil printing unit 3. When the second stencil printing unit 4 does not perform printing, the conveyance speed of the intermediate conveyance unit 5 is controlled so as to be 1520 mm / sec, which is larger than any of the feeding speeds in the respective steps.

  FIG. 2 shows the transition of paper when printing is performed by the first stencil printing unit 3 and not by the second stencil printing unit 4. The length of the paper P in the drawing is shorter than the distance between the first pressing position of the first stencil printing unit 3 and the second pressing position of the second stencil printing unit. In FIG. 2, the vertical axis indicates the leading end position of the paper P and the angle of the first drum 31 at that time. The angle of the first drum 31 is an angle from the reference position.

  FIG. 2 shows a state in which the first drum 31 is rotating beyond one rotation, and illustrates both the paper P that is transported first and the paper P that follows.

  The leading edge of the paper P in the transport direction reaches the vicinity of the first pressing position of the first stencil printing unit 3 when the angle of the first drum 31 is 251 °, and passes through the first pressing position when the angle is 253 °. Then, the delivery by the first stencil printing unit 3 starts, reaches the intermediate position of the intermediate transport unit 5 at 333.4 °, is unloaded from the intermediate transport unit 5 at 0 °, and is 35.6 ° Sometimes it reaches the vicinity of the second pressing position of the second stencil printing unit 4, reaches just before the second pressing position at 53.6 °, and reaches the paper discharge conveyance unit 61 at 169.2 ° To do.

  The paper P is conveyed at a speed equal to the speed sent out by the first stencil printing unit 3 when the angle of the first drum is from 253 ° to 0 °. In this case, the intermediate transport unit 5 is in a state of pulling the paper P.

  The sheet P is transported at a speed equal to the speed transported by the intermediate transport unit 5 when the angle of the first drum exceeds 0 ° and reaches 169.2 °. That is, the paper P passing through the gap is conveyed at a speed of 1520 mm / sec.

  The sheet P is transported at the transport speed of the sheet transport section 61 after the angle of the first drum exceeds 169.2 °. In this embodiment, since the speed of the paper discharge transport unit 61 is the same as the speed of the intermediate transport unit 5, the paper P is continuously transported at a speed of 1520 mm / sec.

  As described above, according to the double-sided printing apparatus 1 according to the embodiment of the present invention, the paper P printed by the first stencil printing unit 3, the second stencil printing unit 4, and the first stencil printing unit 3 is printed. The second stencil printing unit 4 includes an intermediate conveyance unit 5 that conveys the second stencil printing unit 4 and a control unit 7 that controls the conveyance speed of the intermediate conveyance unit 5. Sometimes, the paper P is pressed toward the printing drum 41 in the vicinity of the printing drum 41 and is rotated together with the printing drum 41 to feed out the paper P. When not printing, the paper P is separated from the printing drum 41 and between the printing drum 41. And a press roller 42 for forming a gap, and when the control unit 7 prints the paper P in the first stencil printing unit 3 and does not print in the second stencil printing unit 4, it passes through the gap in the second stencil printing unit 4. The speed of the paper P to be printed is determined by the second stencil printing unit 4 By controlling the conveying speed so as to be higher than the delivery speed by the second stencil printing unit 4 when printing, the distance at which the sheet P is not supported and the paper P is not supported is the second stencil printing unit. Even if the printing unit 4 is longer than the case where printing is performed, the intermediate transport unit 5 allows the sheet P to pass through the gap at a higher speed than when the sheet P is also printed by the second printing unit. Since the paper is accelerated and carried out, the paper P can surely reach the paper discharging / unloading means 61, and a paper jam in front of the paper discharging / unloading means 61 can be avoided.

  Further, according to the stencil printing apparatus 1 according to the embodiment of the present invention, the paper length detection sensor 25 is provided, and the control unit 7 determines that the length of the paper P is the first stencil printing unit 3 and the second stencil printing unit 4. For the paper shorter than the distance between the pressing positions of the first stencil printing unit 3 and the second stencil printing unit 4 by determining whether or not the distance is shorter than the distance between the pressing positions, the second stencil printing plate Since the paper P is transported at a speed higher than any of the speeds when printing by the printing unit 4, it is possible to more reliably avoid the paper jam in front of the paper discharge transport unit 61.

  Further, according to the stencil printing apparatus 1 which is an embodiment of the present invention, the second drum 41 is interlocked with the first drum 31 and rotates at the same speed as the first drum 31, so that the reference position of the first drum 31 and By referring to the rotation information of the drive motor 35, it is possible to calculate both the angle and the speed of the first drum 31 and the second drum 41, the control of the transport speed of the intermediate transport unit 5 becomes easier, and more It is possible to reliably avoid a paper jam in front of the paper discharge conveyance unit 61.

P sheet 1 stencil printing device 3 first stencil printing unit 4 second stencil printing unit 5 intermediate conveyance unit 7 control unit 25 sheet length detection sensor 41 second drum 42 second press roller

Claims (3)

A first stencil printing unit;
A second stencil printing section;
An intermediate transport unit that transports the paper printed by the first stencil printing unit to the second stencil printing unit;
In a stencil printing machine comprising a control unit for controlling the conveyance speed of the intermediate conveyance unit,
The second stencil printing unit is
A rotationally driven printing drum;
At the time of printing, the paper is pressed toward the printing drum in the vicinity of the printing drum and rotated together with the printing drum to feed out the paper. At the time of non-printing, the paper is separated from the printing drum and between the printing drum and the printing drum. And a driven press roller that forms a gap in the
When the control unit prints the paper in the first stencil printing unit and does not print in the second stencil printing unit, the speed of the paper passing through the gap in the second stencil printing unit is the second stencil printing unit. The stencil printing apparatus is characterized in that the conveying speed is controlled so as to be higher than a delivery speed by the second stencil printing unit when printing is performed at a part. Paper length acquisition means for acquiring the length of the paper in the transport direction;
2. The control unit according to claim 1, wherein the control unit determines whether the length of the sheet is shorter than a distance between the first stencil printing unit and the second stencil printing unit. Stencil printing machine.   The printing drum of the second printing unit is interlocked with the printing drum of the first printing unit and rotates at the same rotational speed as the printing drum of the first printing unit. Stencil printing machine.

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