JPH11138964A - Stencil printing press - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stencil printing press which prevents occurrence of blur and offset of a printed image and jamming by preventing sticking of printing paper on a plate cylinder completely for the whole of an ink transfer area and by making the amount of supply of ink constant. SOLUTION: During the transfer of ink onto printing paper P in a pressing contact part A between a plate cylinder 10 and an impression cylinder 50, the opposite end parts and the central part of the fore end of the printing paper P, at least, are gripped by grippers 51 or 61 on the impression cylinder side or the delivery cylinder side and pulled in the direction of rotation of the impression cylinder 50 or a delivery cylinder 60 in conformity with the rotation of the impression cylinder 50 or the delivery cylinder 60 and thereby the whole of the part of the printing paper P to which the ink is already transferred is made to stick on the impression cylinder 50 or the delivery cylinder 60. Even when the grip by the grippers 61 on the delivery cylinder side is canceled, besides, this state of sticking is maintained by delivery means 71-73 until the transfer of ink in the pressing contact part A is finished at least and thereby sticking of the printing paper P on the plate cylinder 10 is prevented completely for the whole of the ink transfer area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stencil printing machine.

[0002]

2. Description of the Related Art As shown in FIG. 11, a stencil printing machine winds a stencil sheet 90 in which perforations corresponding to images are formed around a plate cylinder 91 having ink permeability, and places the stencil sheet 90 in the plate cylinder 91. The ink is leached from the provided ink supply mechanism, and the plate cylinder 91 and the impression cylinder 92 arranged opposite to the plate cylinder 91 are rotated to press the printing paper P with the pressing contact portion A therebetween. Thus, the ink is transferred to the printing paper P through the perforations of the stencil sheet 90 to print an image.

The printing paper P onto which the ink has been transferred is conveyed to the downstream side by the rotation of the plate cylinder 91 and the impression cylinder 92, but is conveyed for a while while being held by the plate cylinder 91 due to the adhesion of the ink. Then, the wind relatively generated by the rotation of the plate cylinder 91 and the centrifugal force acting on the printing paper P cause
The peeling starts sequentially from the leading end of the paper P, and as shown by the imaginary line in FIG.
The sheet is conveyed to the rear end of the sheet while being stuck to one surface.

[0004] Since the above-mentioned ink forms a print image mainly in a form penetrating into the printing paper P, if the time held by the plate cylinder 91 is long, the ink held on the surface of the plate cylinder 91 by a capillary phenomenon is generated. It is supplied to the printing paper P more than necessary. In this case, the sticking time (length) of the sheet P to the plate cylinder 91 is different for each printing mainly due to the influence of the print image and the environment, and is not constant. Will be supplied.

[0005] When the supply amount of ink is large, the ink spreads on the surface of the paper, and the printed image blurs or ink that cannot be completely permeated remains on the surface of the paper. A so-called show-through in which the paper P comes into contact with the back surface and is retransferred occurs. Also, when printing is performed on both sides, the front surface of the paper on which the image is printed first and the back surface of the paper on which the image is printed next are in contact with each other, and the ink is re-transferred, This causes a problem that the image is difficult to read. Further, when the supply amount of the ink is large, in the worst case, the printing paper P is not separated from the plate cylinder 91, and there is a problem that a jam occurs.

Therefore, Japanese Patent Publication No. 2547366 discloses a stencil printing machine which has solved the above-mentioned problems. In this stencil printing machine, as shown in FIG. 11, a clamp 93 is provided on the impression cylinder 92, and the clamp 93 attaches the leading edge of the printing paper P to the impression cylinder 92. The printing paper P clamped by the clamp 93 is pulled downstream along the outer peripheral surface of the impression cylinder 92, thereby causing the printing paper P passing through the pressing contact portion A to adhere to the impression cylinder 92. , The plate cylinder 9
1 is prevented from sticking the printing paper P to the printing paper P. Further, a pair of rollers 94 for pressing both edges of the printing paper P onto the impression cylinder 92 is provided at a position where the clamp 93 passes while holding the front edge of the printing paper P in the attached state. Even if the clamp 93 is released after the edge has passed below the roller 94, both edges of the printing paper P are pressed against the impression cylinder 92 by the roller 93, whereby the printing while passing through the pressing contact portion A is performed. The sheet P is kept attached to the impression cylinder 92 as it is to prevent the printing sheet P from sticking to the plate cylinder 91. Then, when the printing further proceeds and the printing is completed, the leading end of the printing paper P is caught on the peeling nail 95, and the printing paper P is sequentially separated from the impression cylinder 92 from the leading end and discharged. In this way, it is possible to prevent the occurrence of blurring, show-through, and jam of the print image described above.

[0007]

However, the stencil printing machine has the following problems. That is, the pair of rollers 94 is configured to press only the both edges of a narrow range where there is no ink image of the printing paper P against the impression cylinder 92, and only presses both edges of the printing paper P against the impression cylinder 92. Since the paper P is not conveyed to the downstream side along the impression cylinder 92 together with the clamp 93, when the clamp 93 is released after the front edge of the paper has passed the roller 94, the center of the printing paper P The portion bends and floats and sticks to the plate cylinder 91 due to the ink adhesion force. As a result, there is a problem that the above-described print image bleeds and show-through occurs.

The present invention solves such a problem, and can completely prevent the printing paper from sticking to the plate cylinder over the entire surface of the ink transfer area. An object of the present invention is to provide a stencil printing machine capable of preventing bleeding, show-through, and occurrence of jam.

[0009]

In order to solve the above-mentioned problems, a stencil printing machine according to the present invention has a substantially cylindrical shape, a stencil sheet is wound on an outer peripheral surface thereof, and an ink is formed on an inner peripheral surface thereof. Is supplied, and the plate cylinder is rotated with a perforation for leaching the ink on the inner peripheral surface to the outer peripheral surface, and the printing cylinder is rotated at the same peripheral speed as the plate cylinder to press the printing paper between the plate cylinder and the plate cylinder. An impression cylinder that transfers the ink to the printing paper through the stencil paper while squeezing at the contact portion, and the impression cylinder and its peripheral speed are rotated in the same direction in the opposite direction, and are shorter than the ink transfer distance starting from the pressing contact portion. And a discharge cylinder arranged in close proximity to a position along the downstream side of the impression cylinder outer peripheral surface, and at least both ends and a center portion of the leading end of the printing paper supplied to the pressing contact portion, Rotate the leading edge of the printing paper with the rotation of the impression cylinder, and A press drum side gripper that conveys the print paper along the paper discharge cylinder and releases the grip of the leading end of the printing paper at a position close to the discharge cylinder; The adjacent portion of the portion and the adjacent portion of the center portion are gripped from the impression cylinder side gripping claw, and the printing paper is transported along the downstream side of the outer peripheral surface of the discharge cylinder in accordance with the rotation of the discharge cylinder, When the printing paper is separated and discharged from the paper discharge cylinder, a paper discharge cylinder side gripper for releasing the grip of the leading end of the print paper, and a paper discharge cylinder side gripper provided corresponding to the paper discharge cylinder. Discharging means for transporting the print paper released from the gripping by the rotation of the paper discharge cylinder at least until ink transfer at the pressing contact portion is completed, and separating and discharging the paper while separating from the outer peripheral surface of the paper discharge cylinder; Was provided.

Since the present invention is configured as described above,
Printing paper supplied to the pressing contact portion between the impression cylinder and the plate cylinder, first, at least both ends and the center of the tip,
It is held by an impression cylinder side holding claw provided corresponding to the impression cylinder, and is conveyed while being pulled in the rotation direction of the impression cylinder in accordance with the rotation of the impression cylinder. Next, the grip of the leading end of the printing paper is released at a position close to the discharge cylinder, that is, at a position shorter than the printing distance starting from the pressing contact portion and along the downstream side of the outer peripheral surface of the impression cylinder. At the same time, at least a portion adjacent to the both ends and a portion adjacent to the center of the leading end thereof are gripped by the paper discharging drum side gripping claw provided corresponding to the paper discharging drum. It is changed from the drum to the paper discharge drum. Next, the printing paper, of which at least a portion adjacent to the both ends and a portion adjacent to the center portion of the leading end thereof are replaced by the discharge cylinder side gripper, is held on the outer peripheral surface of the impression cylinder in accordance with the rotation of the discharge cylinder. While being conveyed, the sheet is conveyed in an S-shaped state while being pulled in the rotation direction along the outer peripheral surface of the discharge cylinder. Therefore, the printing paper is conveyed while maintaining the state of sticking to the outer peripheral surface of the impression cylinder. On the other hand, the conveyance along the outer peripheral surface of the discharge drum is performed by the discharge means after being performed by the discharge drum side holding claw,
Even if the gripping by the gripper on the paper discharge cylinder side is released, the printing paper is conveyed while maintaining the state of sticking to the outer peripheral surface of the impression cylinder until at least the ink transfer at the pressing contact portion is completed. Then, the printing paper is separated and discharged from the discharge cylinder by the discharging unit.

As described above, during the transfer of the ink to the printing paper at the pressing contact portion, at least the vicinity of both ends and the vicinity of the center of the leading end of the printing paper are held by the holding claws.
Even if the gripping is released, the paper is transported by the paper discharge cylinder in a state where it is stretched between the impression cylinder and the paper discharge cylinder in an S shape even if the grip is released. The entire portion of the ink-transferred portion is stuck to the impression cylinder and the discharge cylinder, so that sticking of the printing paper to the plate cylinder is completely prevented over the entire ink transfer area. For this reason, overfilling of ink is prevented over the entire surface of the ink transfer area, and printing is performed with an appropriate amount (a predetermined fixed amount) of ink. As a result, bleeding and show-through of the printed image are prevented, a clear image is obtained, and the occurrence of jam is prevented.

According to the size of the paper to be printed, the grippers on the impression cylinder side and the discharge cylinder side can be moved along the leading edge of the printing paper, so that at least both end portions and the central portion of the leading edge of the printing paper are always fixed. It is preferable to include a first gripping claw moving means capable of gripping, and a second gripping claw moving means capable of constantly gripping at least the adjacent portions of the both end portions and the adjacent portion of the central portion. When such a configuration is adopted, even when the size of the paper to be printed is changed, the vicinity of both ends and the center of the leading end of the paper is always held by the gripper, so that the printing paper is prevented from floating, and the printing paper is prevented from rising. Sticking to the plate cylinder is completely prevented over the entire surface of the ink transfer area. For this reason, printing papers of various sizes are used.

It is preferable that the outer peripheral length of the paper discharge cylinder be a natural number multiple of the outer peripheral length of the plate cylinder. When such a configuration is adopted, the print image transferred from the plate cylinder side on the printing paper always comes into contact with the same location on the outer peripheral surface of the discharge cylinder, so that the print image is printed on the outer peripheral surface of the discharge cylinder. Even if the ink is transferred from the paper, the ink is not re-transferred from the paper discharge cylinder with respect to the print image on the subsequent print paper, and a clear image without blur is obtained.

[0014] The stencil sheet is wound around the outer peripheral surface of the impression cylinder, ink is supplied to the inner peripheral surface, and the impression cylinder is rotated with a perforation for leaching the ink on the inner peripheral surface to the outer peripheral surface. When the printing paper is nipped by the press contact portion between the printing cylinder and the press cylinder, the ink on the inner peripheral surface of the impression cylinder is transferred to the surface of the printing paper on the impression cylinder side via the stencil paper on the outer peripheral surface of the impression cylinder. It can be configured. When such a configuration is adopted, the impression cylinder is
The press contact portion with the plate cylinder is also used as a plate cylinder that transfers ink to the surface of the printing paper on the impression cylinder side, so that printing is performed on both sides of the printing paper, and the applicable range of the present invention is It can be extended to double-sided printing at low cost. Also, the entire ink-transferred portion of the printing paper on the impression cylinder side comes into contact with and adheres to the outer peripheral surface of the impression cylinder from the pressing contact portion to the portion (closest portion) facing the discharge cylinder. Since the time (length) is always constant, the ink supply amount from the impression cylinder side to the impression cylinder side surface of the printing paper is maintained at a predetermined fixed amount. For this reason,
Excessive ink can be avoided on the impression paper side surface of the printing paper, preventing image bleeding on the impression paper side surface of the printing paper, and preventing the printing paper plate cylinder discharged earlier. The re-transfer of ink that occurs when the surface (rear surface) on the impression cylinder side of the printing paper discharged later comes into contact with the surface (front surface) of the printing paper is also prevented, and a clear image is formed on both sides of the printing paper. can get.

Further, the stencil sheet is formed in a substantially cylindrical shape, and the stencil sheet is wound on the outer peripheral surface thereof, and ink is supplied to the inner peripheral surface thereof. A second rotation in which the impression cylinder and its peripheral speed are rotated at the same speed, the second impression contact portion between the impression cylinder and the impression cylinder comes into pressure contact with the impression cylinder, and ink is transferred to the outer peripheral surface of the impression cylinder via the stencil paper. With two plate cylinders,
The impression cylinder transfers ink transferred from the second plate cylinder to the outer peripheral surface of the impression cylinder to the impression cylinder-side surface of the printing paper when the printing paper is nipped by the pressure contact portion between the impression cylinder and the printing cylinder. Configuration. When such a configuration is adopted, the impression cylinder is
The ink is transferred from the plate cylinder and is also used as a transfer cylinder for transferring the ink to the impression cylinder side of the printing paper at the pressure contact portion with the plate cylinder, and printing is performed on both sides of the printing paper In other words, the applicable range of the present invention is extended to double-sided printing including transfer printing. Also, the entire ink-transferred portion of the printing paper on the impression cylinder side comes into contact with and adheres to the outer peripheral surface of the impression cylinder from the pressing contact portion to the portion (closest portion) facing the discharge cylinder. Since the time (length) is always constant,
The ink supply amount from the impression cylinder side to the surface of the printing paper on the impression cylinder side is maintained at a predetermined fixed amount. For this reason, it is possible to avoid excess ink on the surface of the printing paper on the impression cylinder side, to prevent the image from bleeding on the impression cylinder side of the printing paper, and to prevent the printing paper discharged earlier. The re-transfer of ink which occurs when the surface (rear surface) of the printing paper ejected later comes into contact with the surface (rear surface) of the printing cylinder that is ejected later is also prevented, and both sides of the printing paper are sharp. Image is obtained.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a stencil printing machine according to the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a configuration diagram illustrating a stencil printing machine according to the first embodiment.

As shown in FIG. 1, a stencil printing machine according to this embodiment is roughly divided into a stencil printing machine 1 on which a stencil sheet 10a is wound.
0, a stencil making section 20 for making a stencil sheet 10a, a stencil discharge section 30 for collecting the stencil sheet 10a from the plate cylinder 10, and a printing paper P
A paper feed unit 40 that supplies the printing paper P and conveys the supplied printing paper P to the downstream side while nipping the printing paper P between the plate cylinder 10 and the paper feeding unit 40 that supplies the printing paper P. ,
The paper discharge cylinder 60 is configured to receive the printing paper P from the impression cylinder 50 and transport it downstream, and a paper discharge unit 70 that receives the printing paper P from the paper discharge cylinder 60, transports and stocks the printing paper P.

The impression cylinder 50 is driven to rotate by a drive motor 99. The rotational driving force of the drive motor 99 is applied to the plate cylinder 10 connected to the impression cylinder 50 by a gear, a belt, or the like.
The sheet is transmitted to the discharge cylinder 60, and the plate cylinder 10 and the discharge cylinder 60 are rotated.

The plate cylinder 10 is configured so that a part not including the axis of the cylinder is cut along the axial direction so that the cut section forms a flat surface 10X, and is counterclockwise about the axis. It is driven to rotate. Further, the plate cylinder 10 has a mesh screen made of metal and resin (for example, synthetic fiber) wound around several layers on the outer peripheral surface thereof, and has a middle pressing roller 12 and a middle pressing roller 12 therein. And an ink supply unit 11 for supplying a predetermined amount of ink to the ink supply unit.

The intermediate pressing roller 12 is arranged at a position facing the impression cylinder 50, and is moved in a direction of coming into contact with and separating from the impression cylinder 50 by a drive mechanism (not shown).
When it moves in a direction approaching zero, the outer peripheral portion of the plate cylinder 10 is pushed out from the inner side toward the impression cylinder 50 side, and the ink on the inner peripheral surface side is slid into the outer peripheral surface side. As this ink, an oil-based or water-in-oil emulsion ink which suppresses evaporation of ordinary ink is used.

The plate cylinder 10 is also provided on the flat surface 10X.
A stencil holding claw 13 is provided for holding and releasing the leading end of the stencil sheet 10a by a drive mechanism (not shown), and the stencil sheet 10a is held on the mesh screen by the stencil holding claw 13.

The stencil making section 20 includes a stencil roll 21 around which a stencil stencil made of a nonwoven fabric and a resin film is wound, a thermal head 22 for perforating an image corresponding to print data from the stencil stencil from the stencil roll 21, and a thermal head 22 22
And a stencil feed roller 24 for transporting the stencil sheet toward the plate cylinder 10. The stencil feed roller 24 is configured to convey the leading end of the stencil sheet to the stencil holding claw 13.

The stencil discharging unit 30 collects the stencil sheet 10a wound around the plate cylinder 10 as used when printing is performed using the new stencil sheet after the entire printing process is completed.

The paper supply unit 40 includes a paper supply table 41 on which the print papers P are loaded, a paper supply roller 42 for rotating the print papers P loaded on the paper supply table 41 one by one, and a paper supply roller 42. It comprises a registration roller 43 for temporarily stopping the fed printing paper P and transporting the printing paper P to the vicinity of the contact point between the plate cylinder 10 and the impression cylinder 50 at a predetermined feeding timing.

The impression cylinder 50 has substantially the same outer shape as the plate cylinder 10, and is driven to rotate clockwise around its axis at the same rotational speed. As shown in FIG. 2, a pair of holders 51 a and 51 are provided on both ends in the axial direction on a flat surface 50 </ b> X formed on a part of the outer peripheral surface of the impression cylinder 50, similarly to the plate cylinder 10.
a are erected so as to face each other. A guide shaft 51b extending parallel to the axis of the impression cylinder 50 extends between the holders 51a, 51a.
1b, an impression cylinder side gripper 5 for gripping / releasing the leading end of the supplied printing paper P by a drive mechanism not shown.
A plurality is supported. These impression cylinder side holding claws 51
Is movable along a guide shaft 51b, and is moved to a desired position and fixed by loosely tightening a screw 51c provided to the impression cylinder side holding claw 51. These holders 51a, 51a, guide shaft 51b, screw 51c
This constitutes the impression cylinder side gripper moving means (first gripper moving means) 52.

In this embodiment, three impression cylinder side grippers 51 are provided, and these impression cylinder side grippers 51 are used to hold both ends and the center of the front end of the printing paper used this time. In addition, it is possible. Further, when the paper size is changed, by moving the impression cylinder side gripper 51, both ends and the center of the leading end of the changed paper can be gripped.

Then, between the impression cylinder 50 and the plate cylinder 10, the printing paper P held by the impression cylinder side holding claw 51 and conveyed to the downstream side is nipped, and ink corresponding to the perforation of the stencil sheet 10a is discharged. A pressing contact portion A (see FIG. 3) to be transferred is provided.

As shown in FIG. 1, the discharge cylinder 60 is a plate cylinder 1
0, which has substantially the same outer shape as the impression cylinder 50, and is driven to rotate counterclockwise about its axis at the same rotational speed. As shown in FIG. 2, a pair of substantially similar pairs provided on the impression cylinder 50 are provided on a flat surface 60 </ b> X formed on a part of the outer peripheral surface of the paper discharge cylinder 60, similarly to the plate cylinder 10 and the impression cylinder 50. Holders 61a, 61
a, guide shaft 61b, three (paper discharge cylinder side) holding claws 61
And a screw 61c. These holders 61
a, 61a, the guide shaft 61b, and the screw 61c, the paper discharge cylinder side gripper moving means (second gripper moving means) 62
Is configured.

When the impression cylinder 50 and the discharge cylinder 60 are rotated in the illustrated direction, the impression cylinder-side gripper 51 and the discharge cylinder-side gripper 61 are positioned at the opposing position S between the impression cylinder 50 and the discharge cylinder 60. , Facing (closest to each other), and at this time,
The gripper releasing operation is performed, and the paper discharge cylinder side gripper 61 performs the gripper changing operation at least without time delay. In the present embodiment, even if the gripping operation of the paper ejection cylinder side gripper 61 is delayed by about 5 ° in the rotation angle of the paper ejection cylinder 60, the printing paper P shifts backward due to the inertia of the printing paper P. And the print quality is maintained in an acceptable range.

The press drum side gripper 51 and the paper discharge drum side gripper 61 are arranged in a comb-like manner in the extending direction of the guide shafts 51b, 61b so as not to interfere with each other when approaching the closest. And the holding claws 51, 61
However, the impression cylinder 50,
Notches 53 and 63 are formed in the paper discharge cylinder 60, respectively. Further, the paper discharge cylinder 60 is shorter than the ink transfer distance starting from the pressing contact portion A, and is disposed close to a position along the downstream side of the outer peripheral surface of the impression cylinder 50. Therefore, when the grip is changed, the printing paper P is always pressed by the pressing contact portion A. That is, while the paper is being pressed by the pressing contact portion A, the gripping of the leading end of the printing paper P is performed. Note that the discharge cylinder 60 is spaced apart from the impression cylinder 50 with a predetermined gap T in order to perform predetermined conveyance of the printing paper P favorably. This gap T is 0 <T ≦ 1
mm, more preferably 0.5
mm.

The paper discharge cylinder side gripper 61 maintains the grip of the leading end of the printing paper P pressed by the pressing contact portion A, and bends the print paper P into an S shape by rotation of the paper discharge cylinder 60. It is configured to be transported to a predetermined position on the downstream side.

As shown in FIGS. 6 and 7, a large number of projections 80 are formed on the outer peripheral surface of the paper discharge cylinder 60 in a regular arrangement. The distance between the pitches of the protrusions 80 is set to 0.
It is preferably about 2 mm to 1.5 mm, and in this embodiment,
0.5 mm.

The protruding portions 80 have flat ends, have substantially the same outer diameter in the range of approximately 10 μm to 200 μm, and have substantially the same height in the range of approximately 10 μm to 50 μm. . The projection 80 is formed by, for example, etching a SUS304 plate material. Then, by winding this plate material around the outer peripheral surface of the paper discharge cylinder 60, the paper discharge cylinder 60 having a large number of convex portions 80 on the outer peripheral surface is obtained.

Returning to FIG. 1 again, the paper discharge unit 70 is provided below the paper discharge cylinder 60 for paper conveyance corresponding to the position where the grip is released by the paper discharge cylinder side gripper 61. A paper belt 71 and a suction fan motor 73 located below the paper discharge belt 71 are provided. The paper discharge belt 71 has a large number of suction holes for sucking the printing paper P, which has been released from being gripped by the paper discharge drum side gripper 61, onto the paper discharge belt 71 by driving the fan motor 73. I have.

The paper discharge section 70 also has a U-shaped cross section orthogonal to the paper conveyance direction near the leading end side (right side in the figure) of the paper discharge belt 71, and has an increased apparent rigidity.
A paper discharge wing 72 for flying the conveyed paper P, a paper discharge table 76 for stocking the print paper P flying by the paper discharge wing 72, and a front end side (right side in the figure) of the paper discharge table 76
In the width direction (direction perpendicular to the drawing) of the paper discharge end fence 74 and the paper discharge table 76 which collide the flying paper edge to stop the momentum of the flying and drop the paper, and align the paper leading edge at the time of falling. A pair of side fences 75 are provided side by side and align the width direction of the paper when dropped.

At a position adjacent to the discharge cylinder 60, as shown in FIGS. 1 and 8, a cleaning device J for the discharge cylinder is additionally provided. This cleaning device J
Is the tip of the lever M (left end in the figure) facing the paper discharge cylinder 60.
And a cleaning roller K that is rotatably supported on the cleaning roller K.

The cleaning roller K is provided with the projection 8
It is a continuous porous elastic body having a large number of holes of about 5 μm to 10 μm smaller than the minimum diameter of 0, and each hole is connected by a narrow communication path, and has water absorption and moisture permeability by molding a polyurethane resin, for example. It is made up of Here, in the present embodiment, for example, Ruby Cell A manufactured by Toyo Polymer Co., Ltd. is used as the continuous pore porous elastic body.

The lever M is rotatably supported on a support shaft N. The lever M is disposed below the lever M and is supported by a tension spring R locked on the lever M, with the support shaft N serving as a fulcrum. It is always biased clockwise. The lever M is arranged above the lever M, and is configured to be swingable about the support shaft N by a keep solenoid L having a plunger La pivotally attached to the lever M.

The cleaning device J further includes a microswitch Q adjacent to the end of the lever M (the right end in the figure). The switch lever of this microswitch Q
The tip is bent, and the bent portion Qa is arranged so as to face the end of the lever M.

The plunger La is pulled in by a permanent magnet (not shown) provided in the keep solenoid L during standby (at the time of non-cleaning). In a state of being separated from. At this time, the bent portion Qa of the switch lever is separated from the end of the lever M, and the micro switch Q
Is off.

As shown in FIG. 1, the stencil printing machine of this embodiment further responds to a signal from a cleaning switch 82 for performing cleaning and the above-mentioned microswitch Q to drive motor 99 and keep solenoid L described above. And a CPU 81 for transmitting a predetermined signal to the CPU and controlling the cleaning operation.

Next, the operation of the stencil printing machine according to this embodiment will be described. First, prior to printing, the plate making section 20
The stencil sheet 10a is subjected to stencil making. That is, FIG.
As shown in (2), the heating element of the thermal head 22 is brought into contact with the resin film surface of the stencil sheet unwound from the stencil roll 21 by the rotation of the stencil feed roller 24,
By selectively causing the heat generating element to generate heat, perforation according to image information is performed. The perforated stencil sheet is transported further downstream by the stencil feed roller 24, and the leading end thereof is held by the stencil holding claw 13.
The stencil sheet is wound around the mesh screen of the plate cylinder 10 by rotating the plate cylinder 10 in the counterclockwise direction in the figure. This stencil sheet is cut by a cutter 23 at a predetermined length.

The plate cylinder 10, the impression cylinder 50, and the paper discharge cylinder 60 around which the stencil sheet 10a is wound are waiting at the illustrated positions.
Then, when printing starts, the paper feed roller 42 is driven to rotate, and the top sheet out of the print paper stacked on the paper feed table 41 is fed out, and the drive motor 99 described above is driven. Starting, the plate cylinder 10, the impression cylinder 50 and the discharge cylinder 6
0 starts synchronous rotation in the direction shown.

The fed printing paper P is temporarily stopped by the registration roller 43, and the timing (feed timing) at which the leading edge of the image of the stencil sheet 10a and the transfer position of the printing paper P are aligned. Are fed out toward the pressing contact portion A between the plate cylinder 10 and the impression cylinder 50. The printing paper P is held by the impression cylinder side holding claw 51 at both ends and the center of the leading end thereof on the upstream side of the pressure contact section A (left side of the pressure contact section A), and is pressed by the rotation of the impression cylinder 50. It is transported to the contact portion A.

At this time, the intermediate pressing roller 12 to which a fixed amount of ink is supplied by the ink supply unit 11
, The outer peripheral portion of the plate cylinder 10 is pushed out from the inside toward the impression cylinder 50 side, and the printing paper P is pressed by the plate cylinder 10 and the impression cylinder 50 at the pressing contact portion A. . As a result, the ink accumulated particularly in the nonwoven fabric portion of the stencil sheet 10a and the holes of the mesh screen is removed by the stencil sheet 10a.
Is pressed against the printing paper P through the perforation, and ink transfer (printing) according to the perforation is performed.

The printing paper P on which the ink transfer is performed
Since the both ends and the central portion of the front end are held by the impression cylinder side holding claws 51, the full width of the front end (the entire vertical direction of the front end of the printing paper P with respect to the paper surface) is changed according to the rotation of the impression cylinder 50. It is conveyed while being pulled in the rotation direction of the impression cylinder 50. Therefore, the ink-transferred portion of the printing paper P (the portion on the right side of the pressing contact portion A of the printing paper P) is conveyed in a state where the entirety is stuck to the outer peripheral surface of the impression cylinder 50.

The impression cylinder side gripper 51 and the above-described discharge cylinder side gripper 61 approach each other as the impression cylinder 50 and the discharge cylinder 60 rotate, and the impression cylinder side gripper 51 and the discharge cylinder When the side gripper 61 comes closest, the gripping of the impression cylinder side gripper 51 is released almost simultaneously with the release of the impression cylinder side gripper 51, and the both ends and the center of the leading end of the printing paper P are discharged. It is held by the paper drum side holding claws 61.

The repositioned printing paper P is held near both ends and the center of the leading end by the holding drum-side holding claws 61. The entire width is conveyed while being pulled in the rotation direction of the paper discharge cylinder 60. Therefore, as shown in FIG. 3, the ink-transferred portion of the printing paper P is conveyed in a state where the entire portion is stuck to the outer peripheral surfaces of the paper discharge cylinder 60 and the impression cylinder 50. This sticking state is maintained until the ink transfer at the pressing contact portion A is completed at least by the driving of the fan motor 73 even if the gripping by the paper discharge drum side holding claw 61 is released. Ink transfer for forming an image is well maintained.

As described above, the printing paper P at the pressing contact portion A
During the transfer of the ink to the printing paper P, the vicinity of both ends and the center of the leading end of the printing paper P is close to the impression cylinder side or the discharge cylinder side gripper 51,
61, the impression cylinder 50 or the discharge cylinder 60
Is rotated in the rotation direction of the impression cylinder 50 or the paper discharge cylinder 60, so that the entire portion of the printing paper P on which the ink has been transferred is stuck to the impression cylinder 50 or the paper discharge cylinder 60. The attached state is maintained until ink transfer at the pressing contact portion A is completed at least by driving of the fan motor 73 even when the gripping by the paper discharge cylinder side gripper 61 is released. Is completely prevented over the entire surface of the ink transfer area. For this reason,
Excessive filling of the ink is prevented over the entire surface of the ink transfer area, and printing with an appropriate amount (a predetermined fixed amount) of the ink is performed. As a result, bleeding and show-through of the printed image are prevented, and a clear image is obtained.

By the way, the paper discharge cylinder 60 and the gripper 6
1, when the printing paper P is transported, the ink transfer surface of the printing paper P on the paper discharge cylinder 60 side is formed by the large number of protrusions 80 (see FIGS. 6 and 7) formed on the outer peripheral surface of the paper discharge cylinder 60. In contact.

Here, as described above, since the tip of the convex portion 80 has a flat surface and the outer diameters thereof are substantially equal to each other, the pressure on the printing paper P acts on the flat surface and the conveying force is evenly distributed. The printing paper P is stably transported satisfactorily. In addition, since the large number of convex portions 80 have substantially the same projecting height and are arranged regularly, the printing paper P comes into close contact with the outer peripheral surface of the paper discharge cylinder, so that the conveying force is more uniformly stabilized. The printing paper P is transported more favorably. According to such a configuration of the convex portion 80, even if the paper quality is not so good and the surface is rough, such as straw semi-paper, which is often used in a stencil printing machine, the paper is conveyed well.

Further, since the protruding portion 80 has a flat end at its tip, scratches on the image surface of the printing paper P, which is likely to occur in a sharp shape, for example, are prevented.
It is transported without deteriorating the image quality of the image surface.

The protrusion 80 has a height of protrusion.
It is approximately 10 to 50 μm, and the cross-sectional shape in the direction perpendicular to the protruding direction is circular.
This is because it is easier than a rectangular cross section (triangle, square, etc.). Incidentally, the protrusion height of the convex portion 80 is set to the above or more, and the distance between the pitches of the convex portion 80 is 0.2 mm to
If it is larger than 1.5 mm, when the printing paper P is transported,
It is not preferable because the pressing force of the printing paper P concentrates on the tip of the projection 80 and approaches a sharp shape, which may adversely affect the printing paper P. The limit was a 3 mm pitch.

By the way, as described above, since the ink transfer surface of the printing paper P is in contact with the large number of projections 80, the ink on the image surface is transferred to the tips (flat surfaces) of the projections 80. In some cases, the ink transferred to the projection 80 may be re-transferred by contacting the image surface of the subsequent printing paper.
In particular, this is a case where the ink component is hardly dried.

Here, in the present embodiment, the plate cylinder 10
And the discharge cylinder 60 are rotated at the same rotational speed and have the same outer diameter, so that the print image on the printing paper P transferred from the plate cylinder 10 side always coincides with the same location on the outer peripheral surface of the discharge cylinder 60. Even if the ink from the printing paper P is transferred to the same location upon contact, the ink transferred to the paper discharge cylinder 60 is re-transferred to the same location of the print image on the subsequent printing paper without shifting. Is done. For this reason, a clear image without blurring can be obtained.

It is needless to say that the same effect can be obtained even if the outer peripheral length of the paper discharge cylinder 60 is a natural number multiple of the outer peripheral length of the plate cylinder 10.

As described above, even if the ink is re-transferred from the paper discharge cylinder 60 without shifting to the same position on the image surface of the subsequent printing paper, actually, various factors, such as a shift in the supply timing, etc. Therefore, the position of the ink to be retransferred is slightly shifted for each sheet, so that the image surface often becomes conspicuous as dirt.

In the present embodiment, the outer diameter of the convex portion 80 to which the ink is transferred is approximately 10 to 200 μm, and is smaller than the approximately 0.2 to 0.5 mm line diameter of characters and the like constituting an image. For example, a convex portion on the surface of a body used in an offset printing machine, for example, Japanese Patent Publication No. 54-29300
Japanese Patent Publication No. 3-185 for example.
The contact area with the ink is very small as compared with the convex part constituting the glass piece paper described in JP-A-86-86, and the amount of ink transferred from the image surface to the tip of the convex part is very small. Further, since the outer diameters of the protrusions 80 are made substantially equal to each other and these protrusions are regularly arranged, variations in the transferred ink are reduced.

Therefore, very little ink is re-transferred from the projection 80 to the image surface of the subsequent printing paper, and variations in the re-transferred ink are reduced. Moreover, as described above, the outer diameter of the protrusion 80 is approximately 10 to 200 μm, which is smaller than the line diameter of characters or the like constituting an image, which is approximately 0.2 to 0.5 mm.
Therefore, it is difficult to visually detect the ink transferred to the subsequent printing paper.

That is, even if the ink position to be re-transferred is slightly shifted for each sheet, the stain on the image surface is not sufficiently noticeable. In particular, in a stencil printing machine, a hard-to-dry ink such as an emulsion ink is used, and the stain on the image surface is particularly remarkable. However, even in this case, the stain on the image surface is not sufficiently noticeable.

When the outer diameter of the tip of the convex portion 80 is further reduced within the above range (10 to 200 μm), dirt on the image surface of the printing paper tends to further decrease. Therefore, when a higher image quality is required for the image surface of the printing paper, a smaller diameter can be used.

Returning again to FIG. 1, the printing paper P on which the ink transfer at the pressing contact portion A has been completed at least has been released from the gripping by the paper discharge cylinder side gripper 61, and the printing paper from which the grip has been released is released. Due to the suction force of the fan motor 73, the leading end of the P is sequentially pulled downward from the paper discharge cylinder 60 and is placed on the paper discharge belt 71. On the other hand, the rear end side of the printing paper P is sandwiched between the impression cylinder 50 and the paper discharge cylinder 60 and deforms into an S-shape, and receives a conveyance resistance. This printing paper P
Is moved in the tangential direction of the outer peripheral surface of the paper discharge cylinder 60 by the driving of the paper discharge belt 71 that moves at the same speed as the peripheral speed of the paper discharge cylinder 60, and flies from the paper supply wing 72. The flying printing paper P is supplied to the discharge end fence 74 and the side fence 7.
The paper 5 is regulated in the flight direction and width direction by the paper 5 and is stored in the paper discharge tray 76.

As described above, the printing paper P is not stuck on the plate cylinder 10, is held by the impression cylinder side gripper 51 and is conveyed, and is gripped by the paper discharge cylinder side gripper 61. At this time, the paper discharge cylinder 60
Of the paper discharge cylinder 60 is good.
As a matter of course, the paper is not discharged because the paper is separated and discharged by the discharging means 70.

As described above, since ink is transferred from the image surface of the printing paper P to the tip of the convex portion 80 of the paper discharge cylinder 60, when the stencil sheet 10a is replaced, By wiping the ink, it is preferable to prevent the ink, which had been transferred to the convex portions 80 before the replacement, from being re-transferred onto the image surface of the printing paper after the stencil sheet replacement.
In particular, in a stencil printing machine, as described above, since the hard-to-dry ink such as the emulsion ink is used, the retransfer is more likely to occur.

Therefore, in the present embodiment, the cleaning unit J cleans the convex portion 80 of the paper discharge cylinder 60. Hereinafter, the cleaning operation by the cleaning device J will be described.

On the plate cylinder 10 side, the holding of the base paper holding claws 13 is released and the plate cylinder 10 rotates, and the old stencil sheet 10a wound around the plate cylinder 10 is collected by the plate discharge unit 30 ( (See FIG. 1). Then, a new stencil sheet is wound around the plate cylinder 10 in the same manner as described above.

On the other hand, during standby, the cleaning device J is in the state shown in FIGS. 1 and 8 as described above.
The plunger La is retracted, the cleaning roller K is separated from the outer peripheral surface of the paper discharge cylinder 60, the bent portion Qa of the switch lever is separated from the end of the lever M, and the output of the microswitch Q is turned off. It has become.

Then, the cleaning switch 8 described above is used.
When the switch 2 is turned on, the CPU 81 receives this signal and sends a drive signal to the drive motor 99, so that the plate cylinder 10 and the paper discharge cylinder 60 start rotating together with the impression cylinder 50. Here, in place of the cleaning switch 82, for example, by inputting a command to start a plate making operation in the plate making section 20, the drive motor 9 is turned on.
9 may be sent.

Next, the CPU 81 supplies the keep solenoid L with a current having the opposite polarity, and releases the plunger La fixed and held by the permanent magnet. When the plunger La is released, the lever M rotates counterclockwise about the support shaft N by the urging force of the tension spring R, and the cleaning roller K rotates as shown in FIG. It comes into pressure contact with the outer peripheral surface of the paper discharge cylinder 60, that is, the tip of the projection 80. This pressing force is 1 kgf / 300 mm to 3 kgf /
Preferably it is 300 mm.

At this time, the bent portion Qa of the switch lever is
The end of the lever M is pushed upward in the figure, and the output of the microswitch Q is turned on. Here, the CPU 81
Does not receive an ON signal from the microswitch Q, the CPU 81 determines that some abnormality has occurred, sends an ON signal to abnormality occurrence notification means (not shown) such as an alarm buzzer or a blinking lamp, and notifies the operator of the abnormality. Let me know.

When the cleaning roller K is pressed against the tip of the protruding portion 80 of the rotating paper discharge cylinder 60, the ink is transferred from the flat surface of the protruding portion 80 and absorbed by the cleaning roller K while being driven to rotate. Then, clean this tip.

Here, as described above, the cleaning roller K is, as shown in FIG.
Since the porous elastic body has a large number of holes Ka having a size of about 5 μm to 10 μm smaller than μm, the protrusion 80 does not fit into the hole Ka during cleaning as shown in FIG. Therefore, the ink transferred to the tip of the projection 80 is sufficiently wiped off by the cleaning roller K. It is sufficient that the rotation of the paper discharge cylinder is at least one rotation or more.

When the cleaning is completed in this way, the CPU 81 energizes the keep solenoid L,
The plunger La is sucked. When the plunger La is sucked, the lever M is pressed against the urging force of the tension spring R,
The cleaning roller K is rotated clockwise about the support shaft N, as shown in FIG.
It returns to the standby state in which it is separated from the outer peripheral surface by a predetermined distance. At this time, the bent portion Qa of the switch lever returns to the standby state in which it is separated from the end of the lever M, and the output of the microswitch Q is turned off. Here, if the CPU 81 does not receive the OFF signal from the microswitch Q, the CPU 81 determines that some abnormality has occurred and sends an ON signal to the abnormality occurrence notification means to notify the operator of the abnormality.

On the other hand, when the CPU 81 receives the OFF signal from the microswitch Q, the CPU 81 sends a drive stop signal to the drive motor 99 and the plate cylinder 1 together with the impression cylinder 50.
0, the rotation of the paper discharge cylinder 60 is stopped.

By such an easy operation procedure, the dirt on the convex portion 80 of the paper discharge cylinder 60 can be sufficiently cleaned.

FIG. 4 is a block diagram showing a stencil printing machine according to the second embodiment. In the following embodiments,
As in the first embodiment, a number of convex portions 80 are provided on the outer peripheral surface of the paper discharge cylinder 60, and a cleaning device J is provided for the paper discharge cylinder 60. Are the same as in the first embodiment, and will not be described. In the drawings of the following embodiments, the same elements are denoted by the same reference numerals, and duplicate description will be omitted.

The stencil printing machine of the second embodiment is similar to the stencil printing machine of the first embodiment.
The difference from the embodiment is that the impression cylinder 50 is attached to the plate cylinder 10.
This is the point where the impression cylinder 100 having the function of transferring the ink to the surface of the printing paper P on the impression cylinder side (the back surface of the printing paper P) at the pressing contact portion A with the printing paper P is replaced.

That is, the impression cylinder 100 also serving as the plate cylinder
The stencil sheet 100a for the back side is wound around the outer peripheral surface thereof, and the inner peripheral surface thereof is provided with the intermediate pressing roller 12 and the ink supply unit 11 similar to the first embodiment. It has perforations that allow the ink on the surface to leach onto the outer peripheral surface. On the flat surface 100X of the impression cylinder 100, hold and release both ends and the center of the leading end of the printing paper P described above.
In addition to the impression cylinder side grippers 51, the stencil paper 100a
Is provided in the form of comb teeth.

Further, in the second embodiment, a stencil making section 200 for making the stencil 100a and a plate discharging section 300 for collecting the stencil 100a from the impression cylinder 100 are additionally provided. As in the first embodiment, the plate making section 200 includes a base paper roll 21, a thermal head 22, and a cutter 2.
3 and a base paper feed roller 24, and further includes a transport guide 25.

According to the stencil printing machine of the second embodiment,
The printing paper P held by the impression cylinder side holding claw 51 is
When being pressed by the pressing contact portion A between the plate cylinder 10 and the impression cylinder 100 having the function of the plate cylinder, the ink (corresponding to the perforation of the stencil sheet 10a) is formed on the surface (the upper surface in the figure) of the printing paper P. Is transferred from the plate cylinder 10 side, and the back side of the printing paper P (the lower side in the figure)
The ink corresponding to the perforation of the stencil sheet 100a is
Transferred from 00 side. That is, the printing paper P is subjected to double-sided printing.

The configuration of the second embodiment for performing double-sided printing is realized at low cost because the impression cylinder 100 also functions as a plate cylinder.

The subsequent conveyance of the printing paper P on which the double-sided printing has been performed to the downstream side is exactly the same as in the first embodiment.
The entirety of the ink-transferred portion of the printing paper P on the impression cylinder side moves from the pressing contact portion A to the portion (closest-approaching portion) facing the discharge cylinder 60
Until it comes into contact with and adheres to the outer peripheral surface of the impression cylinder 100, thereafter, it is separated from the outer peripheral surface of the impression cylinder 100.

That is, the time (length) that the ink-transferred portion of the printing paper P is adhered to the outer peripheral surface of the impression cylinder 100 is always constant, and the printing paper P is reliably separated at the opposing portion S.
The ink supply amount from the impression cylinder 100 side to the back surface of the printing paper P is maintained at a predetermined fixed amount, so that the ink can be prevented from being overfilled also on the back surface of the printing paper P.

Therefore, the image is prevented from bleeding even on the back side of the printing paper P, and the back side of the printing paper P discharged later comes into contact with the front side of the printing paper discharged earlier. The re-transfer of the ink is also prevented, so that clear images can be obtained on both sides of the printing paper.

FIG. 5 is a block diagram showing a stencil printing machine according to the third embodiment. The difference between the stencil printing machine of the third embodiment and that of the first embodiment is that the stencil printing machine according to the first embodiment rotates in synchronism with the impression cylinder 50 in exactly the same configuration as the plate cylinder 10, and has a stencil sheet for the back surface on its outer peripheral surface. 101a is wound, and a second plate cylinder 101 is provided in which the pressing contact with the impression cylinder 50 is controlled at a second pressing contact portion B between the impression cylinder 50 and the impression cylinder 50.

The plate making part and the plate discharging part for the plate cylinder 10 and the plate making part and the plate discharging part for the second plate cylinder 101 are omitted because the figure becomes complicated.

According to the stencil printing machine of the third embodiment,
When the second plate cylinder 101 and the impression cylinder 50 come into pressure contact with each other at the second pressure contact portion B, ink corresponding to the perforation of the stencil sheet 101a is applied to the outer peripheral surface of the impression cylinder 50 with the second plate cylinder 101.
Transcribed from the side. When the printing paper P held by the impression cylinder side holding claw 51 is nipped by the pressing contact portion A between the plate cylinder 10 and the impression cylinder 50, the stencil sheet 10a is formed on the surface of the printing paper P. The ink corresponding to the perforation is transferred from the plate cylinder 10 side, and the ink on the second plate cylinder 101 side transferred to the outer peripheral surface of the impression cylinder 50 is transferred to the back surface of the printing paper P. That is, the printing paper P is subjected to double-sided printing.

The subsequent conveyance of the printing paper P on which the duplex printing has been performed to the downstream side is exactly the same as that of the second embodiment.
The time (length) during which the ink-transferred portion of the printing paper P is stuck to the outer peripheral surface of the impression cylinder 50 is a constant value from the pressing contact portion A to the portion S facing the discharge cylinder 60, and Since the amount of the ink transferred to the outer peripheral surface of the impression cylinder 50 is maintained at a predetermined value, the ink supply amount from the impression cylinder 50 to the back surface of the printing paper P is more easily controlled than in the second embodiment and is a predetermined constant amount. Kept in quantity. As a result, similarly to the second embodiment, the image is prevented from bleeding on the back surface of the printing paper P, and the back surface of the printing paper P discharged later with respect to the front surface of the printing paper P discharged earlier. The re-transfer of the ink caused by the contact of the ink is further prevented, and clear images can be obtained on both sides of the printing paper.

Although the invention made by the inventor has been specifically described based on the embodiment, the invention is not limited to the above embodiment, and can be variously modified without departing from the gist of the invention. Needless to say,
For example, in the above embodiment, the paper discharge cylinder side gripper 6
1 and the impression cylinder side gripper 51, the ejection cylinder 60 and the impression cylinder 50
And three each, but it may be provided on a separate body (for example, a ring) that rotates synchronously with the discharge cylinder 60 and the impression cylinder 50, and the number is not limited to this. At least the vicinity of the both ends and the center of the leading end of the P may be added, and it may be possible to rotate synchronously with the discharge cylinder 60 and the impression cylinder 50.

In the above embodiment, the grippers 51 and 61 are manually moved and fixed along the leading edge of the sheet. However, the air for moving the grippers 51 and 61 in the above-described direction is used. In addition to providing an actuator such as a cylinder, the CPU stores in advance in the CPU the positions at which the grippers 51 and 61 can grip at least both ends and the center of the paper in accordance with the size of the paper to be used. The actuator may be controlled in accordance with an input signal from an input switch to move the grippers 51 and 61 to positions where at least both ends and the center of the paper to be used can be gripped.

Further, a number of convex portions 8 on the outer peripheral surface of the paper discharge cylinder 60 are provided.
0. Regarding the cleaning device J, the cleaning device J is particularly effective for a stencil printing machine using a hard-to-dry ink such as an emulsion ink. For example, when a roller is employed instead of the paper discharge belt 71 and this roller is pressed against the paper discharge cylinder to constitute a discharge means, the present invention can be similarly applied to this roller. Further, reduction of ink retransfer from the paper discharge cylinder 60 to the image surface of the printing paper P,
From the viewpoint of maintaining the cleaning function of a large number of convex portions 80 on the outer peripheral surface of the discharge drum 60, the discharge drum 60 having the convex portions 80 is a type in which the print paper P is further conveyed by the gripper 61. For example, a type in which the printing paper P is conveyed while being held on the outer peripheral surface of the paper discharge cylinder 60 by suction may be used.

Further, with respect to the cleaning device J, in particular, the cleaning roller K which is driven and rotated is made of a continuous-porous porous elastic body. However, it is also possible to use another cleaning member adapted to the shape of the paper discharge cylinder 60. For example, a cleaning cloth made of a nonwoven fabric can be used. Further, the cleaning device J can not only sufficiently clean the large number of convex portions 80 having the above configuration, but also, for example, Japanese Patent Publication No. 54-293.
No. 00 publication, for example, Japanese Patent Publication No. 3-1
It is also possible to sufficiently clean the projections constituting the glass piece paper described in Japanese Patent No. 8586. In this case, the diameter of the non-circular hole constituting the porous elastic body is not limited to the above-described approximately 5 μm to 10 μm, and the maximum major diameter of the hole may be the matte convex portion provided on the outer peripheral surface of the paper discharge cylinder or It is preferable that the minimum diameter of the convex portion of the glass piece paper is smaller, so that the convex portion can be sufficiently cleaned without the convex portion being fitted in the hole, and the catch between the hole and the convex portion is reduced. In addition, the life of the cleaning roller K can be extended.

[0093]

As described above, the stencil printing machine according to the present invention, at the time of ink transfer to the printing paper at the press contact portion between the plate cylinder and the impression cylinder, at least the both ends and the central portion of the leading end of the printing paper,
The ink transferred portion of the printing paper is held by the gripper on the impression cylinder or discharge cylinder side and pulled in the direction of rotation of the impression cylinder or discharge cylinder in accordance with the rotation of the impression cylinder or discharge cylinder. The entirety will be stuck on the impression cylinder and the discharge cylinder, and even if the grip by the discharge cylinder side gripper is released, the above-mentioned stuck state will be changed by the discharging means at least at the time of ink transfer at the pressing contact portion. Since it is maintained until the printing is completed, the sticking of the printing paper to the plate cylinder can be completely prevented over the entire ink transfer area. Therefore, it is possible to prevent the ink from being overfilled over the entire surface of the ink transfer area, and it is possible to perform printing with an appropriate amount (a predetermined fixed amount) of the ink. As a result, it is possible to prevent the occurrence of bleeding and show-through of the printed image, to obtain a clear image, and to prevent the occurrence of jam.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a stencil printing machine according to a first embodiment.

FIG. 2 is a perspective view showing an impression cylinder, a paper discharge cylinder, and their holding claws used in the stencil printing machine of FIG.

FIG. 3 is an explanatory diagram showing an operation of the stencil printing machine of FIG. 1;

FIG. 4 is a configuration diagram illustrating a stencil printing machine according to a second embodiment.

FIG. 5 is a configuration diagram illustrating a stencil printing machine according to a third embodiment.

FIG. 6 is a partially enlarged perspective view showing a convex portion of a paper discharge cylinder used in the stencil printing machine of the first to third embodiments.

FIG. 7 is a sectional view showing a convex portion of the paper discharge cylinder of FIG. 6;

FIG. 8 is an enlarged configuration diagram showing a cleaning device used in the stencil printing machine of the first to third embodiments.

9 is an explanatory diagram illustrating a cleaning operation of the cleaning device of FIG.

FIG. 10 is an explanatory diagram showing a cleaning state of the outer peripheral surface of the paper discharge cylinder by the cleaning device of FIG. 8;

FIG. 11 is a schematic configuration diagram showing a stencil printing machine according to the related art.

[Explanation of symbols]

10: plate cylinder, 10a: stencil paper, 11: ink supply unit,
Reference numeral 12: middle press roller, 50, 100: impression cylinder, 51: impression cylinder side gripper, 52: impression cylinder side gripper moving means, 60: discharge cylinder, 61: discharge cylinder side gripper, 62: discharge cylinder Side gripper moving means, 70 ... discharging means, 100a ... stencil sheet of impression cylinder, 101 ... second plate cylinder, 101a ... stencil sheet of second discharging cylinder, A ... pressing contact portion, B ... second Press contact, P ...
Printing paper, S: The proximity position between the impression cylinder and the discharge cylinder.

Claims (5)

[Claims] 1. A stencil sheet having a substantially cylindrical shape, stencil paper being wound on an outer peripheral surface thereof, and ink being supplied to an inner peripheral surface thereof.
A plate cylinder that rotates with a perforation that allows the ink on the inner peripheral surface to leach into the outer peripheral surface; and a press contact portion between the plate cylinder and the plate cylinder that rotates at the same peripheral speed as the plate cylinder. An impression cylinder for transferring the ink to the printing paper via the stencil sheet while pressing the ink cylinder; and an ink transfer distance starting from the pressing contact portion by rotating the impression cylinder and its peripheral speed in the same direction. A paper discharge cylinder that is shorter and located closer to a position along the downstream side of the outer peripheral surface of the impression cylinder; and at least both end portions and a central portion of the leading end of the printing paper supplied to the pressing contact portion. In addition, the leading end of the printing paper is transported along the downstream side of the outer peripheral surface of the impression cylinder in accordance with the rotation of the impression cylinder, and the gripping of the leading end of the printing paper is released at a position close to the discharge cylinder. Perform the impression cylinder side holding claw, the impression cylinder and the At a position where the printing paper is close to the paper discharge cylinder, at least a position adjacent to the both ends and a position adjacent to the central portion of the leading end of the printing paper are replaced with the impression cylinder side gripper, and the printing paper is discharged. When the print paper is conveyed along the downstream side of the outer peripheral surface of the discharge cylinder in accordance with the rotation of the paper cylinder and the print paper is separated and discharged from the discharge cylinder, the discharge for releasing the grip of the leading end of the print paper is released. Paper cylinder side gripping claw, The printing paper provided corresponding to the paper ejection cylinder, the gripping of which is released by the paper ejection cylinder side gripping claw, at least until the ink transfer at the pressing contact portion is completed. A stencil printing machine comprising: a discharge unit that conveys the paper in accordance with the rotation of the paper discharge cylinder, and separates and discharges the paper while separating from the outer peripheral surface of the paper discharge cylinder. 2. The printing drum-side and discharge cylinder-side holding claws are movable along the leading edge of the printing paper in accordance with the size of the paper to be printed, and at least both ends and the center of the leading edge of the printing paper. A first gripper moving means for constantly gripping the first gripper; and a second gripper moving means for constantly gripping at least a location adjacent to the both end portions and a location adjacent to the central portion. A stencil printing machine as described. 3. An apparatus according to claim 1, wherein an outer peripheral length of said discharge cylinder is a natural number multiple of an outer peripheral length of said plate cylinder.
A stencil printing machine as described. 4. The impression cylinder has a perforation on which a stencil sheet is wound on an outer peripheral surface thereof, ink is supplied to an inner peripheral surface thereof, and ink on the inner peripheral surface is leached into the outer peripheral surface. When the printing paper is rotated and squeezed at the pressing contact portion between the printing cylinder and the plate cylinder, the ink on the inner peripheral surface side of the impression cylinder is pressed through the stencil sheet on the outer peripheral surface side of the printing cylinder to pressure the printing paper. The stencil printing machine according to any one of claims 1 to 3, wherein the image is transferred to a surface on a cylinder side. 5. A stencil sheet having a substantially cylindrical shape, stencil paper being wound on an outer peripheral surface thereof, and ink being supplied to an inner peripheral surface thereof.
The impression cylinder has a perforation for leaching ink on the inner peripheral surface to the outer peripheral surface, and rotates at the same peripheral speed as the impression cylinder, and is pressed against the impression cylinder at a second pressing contact portion between the impression cylinder and the impression cylinder. A second plate cylinder for contacting and transferring the ink to the outer peripheral surface of the impression cylinder via the stencil paper, wherein the impression cylinder is a pressing contact portion between the printing paper and the plate cylinder. The method according to claim 1, wherein, when the pressing is performed, the ink transferred from the second plate cylinder to the outer peripheral surface of the impression cylinder is transferred to a surface of the printing paper on the impression cylinder side. 5. A stencil printing machine according to claim 1.