JP2001239733A - Stencil printing equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a printed image from being deteriorated by paper dusts adhered to the transfer sheet of a transfer cylinder. SOLUTION: In stencil printing equipment equipped with a plate cylinder 1, onto the outer peripheral surface of which a stencil original paper can be freely installed, a transfer cylinder 2 having a transfer sheet 11, on which an ink image is transferred from the stencil original paper contacting under pressure, and an impression cylinder 3, a printing paper 14 guided between the transfer cylinder 2 and which is carried to a paper discharging side and, at the same time, which gives a printing pressure for transferring the ink image on the transfer sheet 11 to a printing paper 14 during the carrying process, a paper dust removing mechanism 21 for removing the paper dusts adhered to the transfer sheet 11 of the transfer cylinder 2 having a cleaning roll 24, which nearly abuts against the transfer sheet 11 and is rotatable, a water supplying roll 30, the diameter of which is smaller than that of the cleaning roll 24 and which nearly abuts against the cleaning roll 24 and is rotatable, and a water tray 33, in the water of which the lower side of the water supplying roll 30 is submerged, is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention includes a plate cylinder, a transfer cylinder, and an impression cylinder, and transfers an ink image to a transfer cylinder once, and re-transfers the transferred ink image to printing paper to print a print image. The present invention relates to a stencil printing apparatus to be obtained, and more particularly to a technique for preventing paper dust generated from printing paper.

[0002]

2. Description of the Related Art In a stencil printing apparatus that directly transfers an ink image from a stencil sheet to a printing sheet without a transfer cylinder, the printing pressure changes due to the ink absorption performance of the printing sheet and the thickness of the printing sheet. Since the ink transfer amount changes, it is difficult to adjust the ink transfer amount to an appropriate amount.

However, in a stencil printing apparatus having a transfer cylinder, ink is transferred to a transfer sheet of a transfer cylinder having a constant ink absorption performance and a constant thickness. The transfer amount can be easily adjusted to an appropriate amount. In order to transfer the ink image whose ink amount is controlled in this way to the print paper, only a predetermined ink transfer amount is naturally transferred to the print paper. Thereby, the stencil printing apparatus having the transfer cylinder can easily adjust the ink transfer amount to an appropriate amount, and can obtain a clear printed image.

A conventional stencil printing apparatus having such a transfer cylinder is shown in FIG. In FIG. 6, the plate cylinder 10
Numeral 0 is provided rotatably, and a screen 101 that can swell outward and that can pass through the ink 102 is stretched around the outer periphery of the plate cylinder 100. A squeegee roll 103 is disposed in the internal space of the plate cylinder 100. The squeegee roll 103 is at a standby position where the squeegee roll 103 is separated from the inner surface of the screen 101, and presses the screen 101 from the inner surface to bulge the screen 101 to the outside. It is provided movably between a pressing position to be brought into pressure contact with the body 105.

[0005] The squeegee roll 103 is mounted on the plate cylinder 100.
At the time of this rotation, the ink 102 is screened using the gap with the doctor roll 104.
Is configured to be supplied to the inner peripheral surface. Further, a stencil clamp portion (not shown) is provided on the outer periphery of the plate cylinder 100, and the stencil sheet is mounted on the outer peripheral surface by clamping the leading end of the stencil sheet (not shown) with the stencil clamp portion. As the stencil sheet, a stencil sheet which has been thermally perforated based on desired image information is attached at the time of printing.

The transfer cylinder 105 is rotatably provided near the lower part of the plate cylinder 100, and a transfer sheet 106 capable of transferring ink is mounted on the outer periphery of the transfer cylinder 105.

The impression cylinder 107 is rotatably provided near the lower portion of the transfer cylinder 105 and is movably provided between a pressure contact position where the impression cylinder 107 is pressed against the transfer cylinder 105 and a standby position where the impression cylinder 107 is separated from the transfer cylinder 105. ing. A paper feed unit 108 is provided below one side of the impression cylinder 107, and a paper discharge unit 109 is provided on one side of the impression cylinder 107 and above the paper supply unit 108.

The paper supply unit 108 includes a paper supply table 111 on which print papers 110 are stacked and arranged, a paper supply roll 112 which presses the uppermost one of the print papers 110 loaded on the paper supply table 111, It has a guide roll 113 and a timing roll 114 located downstream of the feeding roll 112.

The guide roll 113 is a timing roll 1
The timing roll 114 can be moved between a pressing position and a separating position with respect to the timing roll 14, and the timing roll 114 is configured to be rotatable.
Then, the guide roll 113 and the timing roll 114
Supplies the printing paper 110 supplied between the guide roll 113 and the timing roll 114 between the transfer cylinder 105 and the impression cylinder 107 in synchronization with the rotation timing of the transfer cylinder 105 and the impression cylinder 107.

The paper discharge section 109 has a paper discharge guide (not shown) for guiding the printing paper 110 separated from the impression cylinder 107 in the transport direction, and a paper discharge table 115 arranged downstream of the paper transport.

In the above-described configuration, a stencil sheet having a stencil made is mounted on the outer peripheral surface of the plate cylinder 100, and the impression cylinder 107 is positioned at the press-contact position, and as shown by arrows in FIG. The plate cylinder 100, the transfer cylinder 105, and the impression cylinder 10 are arranged in the same direction and at the same circumferential speed at the press contact locations.
7 is rotated. When the squeegee roll 103 is located at the pressing position, the screen 101 swells outward and is pressed against the transfer cylinder 105, and the pressure force causes the ink 102 to bleed out from the perforations of the stencil sheet to transfer the ink image to the transfer cylinder 105. Is transferred to the transfer sheet 106. At a predetermined timing, a printing paper 110 is conveyed from the paper feeding unit 108 between the transfer cylinder 105 and the impression cylinder 107, and the printing paper 1
The ink image on the transfer sheet 106 of the transfer cylinder 105 is transferred to 10. That is, printing is performed by temporarily transferring an ink image based on perforations of a stencil sheet (not shown) to the transfer cylinder 105 and further transferring the ink image transferred to the transfer cylinder 105 to the printing paper 110.

By the way, paper dust is generated from the printing paper 110 due to friction with other members such as the paper feed roll 112, and the like.
As shown in FIG. 7, the paper dust adhered to the printing surface of the printing paper 110 is directly transferred to and adhered to the transfer sheet 106 when the printing paper 110 is pressed against the transfer cylinder 105. or,
The paper powder separated from the printing paper 110 floats in the air and adheres to the transfer sheet 106. Thus, the transfer cylinder 1
When the paper dust adheres to the transfer sheet 106 of No. 05, the paper dust retains the ink 102 and a predetermined amount of the ink 102 is not transferred to the printing paper 110, so that the image corresponding to the place where the paper dust adheres becomes thin. Or the paper dust holding a large amount of the ink 102 is transferred to the printing paper 110, and the image corresponding to the portion where the paper dust adheres due to the large amount of the ink 102 being transferred to the printing paper 110 by a large amount or more is required. As described above, the image becomes darker and has a wider area, resulting in image deterioration.

In the above-described conventional stencil printing apparatus, the paper supply unit 108 and the paper discharge unit 109 are both disposed on the same side with respect to the impression cylinder 107, and the paper supply roll 112 of the paper supply unit 108 110 so that the surface of the transfer cylinder 105 does not contact the transfer sheet 106,
The surface on which the paper dust is generated due to the friction between the paper sheet and the printing surface is made opposite to the printing surface, thereby preventing the paper dust from adhering to the transfer sheet 106 as much as possible, thereby preventing the deterioration of the printed image due to the paper dust.

[0014]

However, in the conventional stencil printing apparatus, a certain effect can be expected with respect to the transfer of the paper dust generated by the paper feed roll 112 directly to the transfer sheet 106. The paper dust generated by the timing roll 114 is directly transferred to the transfer sheet 1.
06 has no effect, nor does it have any effect on paper dust floating in the air adhering to the transfer sheet 106. Further, paper dust from the printing paper 110 is mainly generated from the paper feeding unit 108, but also from other places. As long as the printing paper 110 is transported inside the apparatus, generation of paper dust from the printing paper 110 is reduced. It is difficult to remove.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has as its object to provide a stencil printing apparatus capable of preventing deterioration of a printed image due to paper dust attached to a transfer sheet of a transfer cylinder. I do.

[0016]

According to a first aspect of the present invention, a stencil sheet perforated based on image information is rotatable on an outer peripheral surface, and ink is supplied from the inner peripheral surface side to the stencil sheet. A transfer cylinder having a flexible printing drum, a transfer sheet having an outer peripheral surface on which an ink image is transferred from the stencil sheet pressed and pressed in synchronization with the printing drum, and rotating in synchronization with the rotation of the transfer cylinder; And a press drum that applies a printing pressure for transferring the ink image of the transfer sheet to the print paper in the conveyance process while conveying the print paper guided between the transfer cylinder and the discharge side. In the stencil printing apparatus provided, a paper dust removing mechanism for removing attached paper dust is provided on the transfer sheet side of the transfer cylinder.

In this stencil printing apparatus, paper dust is transferred to the transfer sheet of the transfer cylinder directly from the printing paper, or paper dust floating in the air is attached to the transfer sheet of the transfer cylinder. The paper dust thus removed is removed from the transfer sheet by the paper dust removing mechanism.

According to a second aspect of the present invention, there is provided the stencil printing apparatus according to the first aspect, wherein the paper dust removing mechanism has an operation state for removing the paper dust and a non-operation state for not removing the paper dust. It is characterized by being switchable.

In this stencil printing apparatus, paper dust on the transfer sheet can be removed as needed at any time in addition to the effect of the first aspect of the present invention.

The invention of claim 3 is the invention of claim 1 or claim 2.
The stencil printing machine according to claim 1, wherein the paper dust removing mechanism is rotated downstream from a pressing position at which the transfer cylinder presses against the impression cylinder, and from a pressing position at which the transfer cylinder can press against the plate cylinder. It is located in the upstream area.

In this stencil printing apparatus, in addition to the effects of the first and second aspects of the present invention, paper dust adhering to the transfer sheet of the transfer cylinder can be removed before the position where the paper dust is pressed against the plate cylinder.

According to a fourth aspect of the present invention, in the stencil printing apparatus according to any one of the first to third aspects, the paper dust removing mechanism has a diameter smaller than a diameter of the transfer cylinder and substantially abuts on the transfer sheet. A rotatable cleaning roll in contact with the cleaning roll, a rotatable water supply roll having a diameter smaller than the diameter of the cleaning roll and substantially abutting on the cleaning roll, and a water tray in which a lower side of the water supply roll is flooded. Features.

In the stencil printing apparatus, the paper dust is removed by transferring the water in the water tray in the order of the water supply roll and the cleaning roll. The paper powder adhering to the transfer sheet floats with the water transferred onto the transfer sheet of the transfer cylinder from the transfer cylinder, and the floated paper powder is transferred in reverse order to the cleaning roll and the water supply roll by the delta effect, thereby supplying water. The paper powder transferred to the roll is settled in water in a water tray.

According to a fifth aspect of the present invention, there is provided the stencil printing apparatus according to the fourth aspect, wherein at a position close to the water supply roll,
Further, a squeegee roll capable of adjusting a gap with the water supply roll is provided at a rotation position upstream of a rotation position at which the cleaning roll substantially abuts.

In this stencil printing machine, in addition to the effect of the fourth aspect, the water film thickness of the water supply roll can be controlled by adjusting the gap amount of the squeegee roll.

According to a sixth aspect of the present invention, in the stencil printing machine according to the fourth aspect, the cleaning roll is arranged such that an operation position of the transfer cylinder substantially in contact with the transfer sheet and a position of the transfer sheet of the transfer cylinder. It is characterized by being movable between a non-operating position that is separated.

In this stencil printing apparatus, in addition to the operation of the fourth aspect, switching between the operating state and the non-operating state can be performed by moving the position of the cleaning roll.

According to a seventh aspect of the present invention, in the stencil printing apparatus according to any one of the first to third aspects, the paper dust removing mechanism is a brush that comes into contact with the transfer sheet of the transfer cylinder. I do.

In this stencil printing machine, in the operation of the first to third aspects of the invention, the paper dust is removed by scraping the paper dust attached to the transfer sheet with a brush.

According to an eighth aspect of the present invention, in the stencil printing apparatus according to any one of the first to sixth aspects, the paper dust removing mechanism has an ink removing means for removing ink attached to the cleaning roll. Features.

In the stencil printing apparatus, in addition to the effects of the first to sixth aspects, when the ink on the transfer sheet is transferred to the cleaning roll, the ink transferred to the cleaning roll is removed by the ink removing means. Removed.

According to a ninth aspect of the present invention, in the stencil printing machine according to the eighth aspect, the ink removing means is a blade that comes into contact with an outer peripheral surface of the cleaning roll.

In this stencil printing apparatus, in the operation of the eighth aspect of the invention, the ink is removed by scraping off the ink transferred by the cleaning roll with a blade.

According to a tenth aspect of the present invention, in the stencil printing machine according to the eighth aspect, the ink removing means includes a cleaning liquid application section for applying a cleaning liquid to an outer peripheral surface of the cleaning roll, and the cleaning liquid application section. A cleaning liquid wiping unit for wiping the cleaning liquid applied to the outer peripheral surface of the cleaning roll.

In this stencil printing machine, in the operation of the eighth aspect of the invention, the ink is removed by dissolving or swelling the ink with the applied cleaning liquid, and wiping the dissolved or swollen ink together with the cleaning liquid. Can be

[0036]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show a first embodiment of the present invention. FIG. 1 is a schematic configuration diagram of a main part of a stencil printing apparatus. FIG. 2 is a schematic configuration diagram of a paper dust removing mechanism. The stencil printing apparatus includes a plate cylinder 1, a transfer cylinder 2 and an impression cylinder 3 which are provided rotatably and have substantially the same diameter.
And the transfer cylinder 2 and the impression cylinder 3, as indicated by arrows in FIG.
By the driving force of a main motor (not shown), they are rotated in the same direction and at the same circumferential speed at the places where they are close to and pressed against each other.

The plate cylinder 1 is rotatably supported at a predetermined position in the apparatus main body S about the plate cylinder shaft 1a. The plate cylinder 1 can swell outward on the outer periphery of the plate cylinder 1 and passes through the ink 5. A possible screen 6 is stretched. A squeegee roll 7 is provided in the internal space of the plate cylinder 1. The squeegee roll 7 has a standby position separated from the inner surface of the screen 6 and a screen 6 that presses the screen 6 from the inner surface.
Is movably provided by a driving force of a squeegee roll moving motor (not shown) between a pressing position for swelling outward and pressing against the transfer cylinder 2. The squeegee roll 7 rotates together with the plate cylinder 1, and at this time, a predetermined amount of the ink 5 is supplied from the inner surface of the screen 6 by utilizing a gap with the doctor roll 8.

Further, a stencil clamping section (not shown) is provided on the outer periphery of the plate cylinder 1, and the stencil sheet is mounted on the outer peripheral surface by clamping the leading end of the stencil sheet (not shown) with the stencil clamping section. . At the time of printing, a stencil sheet which has been heat-perforated based on desired image information and is stencil-made is attached.

The transfer cylinder 2 is arranged near the lower portion of the plate cylinder 1 and is rotatably supported at a predetermined position in the apparatus main body S about the transfer cylinder shaft 2a. A transfer sheet 11 on which ink can be transferred is wound around the outer circumference of the transfer cylinder 2. The transfer sheet 11 is an elastic member and an oil-resistant sheet, and is made of, for example, nitrile rubber.

The impression cylinder 3 is located near the lower portion of the transfer cylinder 2,
a, and is rotatably provided by a driving force of a pressure drum moving motor (not shown) between a pressure contact position for pressing against the transfer drum 2 and a standby position for separating from the transfer drum 2. ing. A paper clamp (not shown) is provided on the outer periphery of the impression cylinder 3. The paper clamp clamps the leading end of the printing paper 14 conveyed between the transfer cylinder 2 and the impression cylinder 3 from the paper supply unit 13 and releases the clamp at the entrance of the paper discharge unit 15.

The paper supply unit 13 includes a paper supply table 16 on which the print papers 14 are stacked, and a paper supply roll 17 that presses the print paper 14 loaded on the paper supply table 16 at the highest position.
It has a guide roll 18 and a timing roll 19 located downstream of the paper feed roll 17. The guide roll 18 can move between a pressing position and a separating position with respect to the timing roll 19, and the timing roll 19 is selectively rotatable by a driving force of a main motor (not shown). Then, the guide roll 18 and the timing roll 19 synchronize the printing paper 14 supplied between the guide roll 18 and the timing roll 19 with the rotation timing of the transfer cylinder 2 and move the printing paper 14 between the transfer cylinder 2 and the impression cylinder 3. Feed paper.

The paper discharge section 15 is a paper discharge guide (not shown) for guiding the printing paper 14 separated from the impression cylinder 3 in the transport direction.
And a paper discharge table 20 arranged downstream of the conveyance.

The paper dust removing mechanism 21 is in the vicinity of the transfer cylinder 2, downstream of the pressure contact position where the transfer cylinder 2 is pressed against the impression cylinder 3, and the transfer cylinder 2 can be pressed against the plate cylinder 1. It is arranged in an area E (shown in FIG. 2) upstream of the pressure contact position. As shown in FIG. 2, the paper dust removing mechanism 21 has a mechanism main body 23 rotatably supported around a support shaft 22 at a predetermined position in the apparatus main body S. Are rotatably supported. A worm wheel 25 is provided in an arc portion at the upper end of the mechanism body 23, and a worm gear 26 meshes with the worm wheel 25. A spur gear 27 is fixed to a shaft 26a of the worm gear 26, and a spur gear 2 fixed to a rotation shaft 28a of a drive motor 28 is fixed to the spur gear 27.
9 are engaged. When the drive motor 28 rotates, the rotation is transmitted to the spur gear 29, the spur gear 27, the worm gear 26, and the worm wheel 25 in this order, so that the cleaning roll 24 is rotated together with the mechanism main body 23. Moves between an operation position (shown in FIG. 2) of the transfer cylinder 2 substantially in contact with the transfer sheet 11 and a non-operation position separated from the transfer sheet 11.

The cleaning roll 24 has a diameter smaller than the diameter of the transfer cylinder 2 and is made of, for example, silicone rubber. At a position inside the mechanism main body 23, a water supply roll 30 is substantially in contact. The water supply roll 30 has a shaft 3
The arm 32 is rotatably supported at the distal end of the arm 32 rotatably supported with 1 as a fulcrum. The rotation of the arm 32 adjusts the substantially contact state with the cleaning roll 24. The water supply roll 30 has a diameter smaller than the diameter of the cleaning roll 24 and is made of, for example, a stainless steel material, and its lower side is submerged in the water 34 of the water tray 33. Water tray 3
Water 3 in a water tank 35 can be supplied to the inside 3 by a water pump 36. The water amount sensor 37 detects whether or not the capacity of the water 34 in the water tray 33 is a predetermined amount, and the output of the water amount sensor 37 keeps the capacity of the water 34 in the water tray 33 at a substantially constant amount. .

The squeegee roll 38 has a diameter smaller than the diameter of the cleaning roll 24 and is made of, for example, silicon rubber. The base end of the squeegee roll 38 is rotatably supported by the mechanism main body 23 around a shaft 39 as a fulcrum. It is rotatably supported. The squeegee roll 38 is located at a position close to the water supply roll 30 and the cleaning roll 24.
Are disposed at a rotational position upstream of the rotational position at which they substantially abut. The gap with the water supply roll 30 can be adjusted by rotating the arm 40.

On the other hand, an operation panel (not shown) is provided at a predetermined position of the apparatus main body S. The operation panel includes a print start key and a print stop key (not shown), a numeric keypad for inputting the number of sheets to be printed, and the like. The paper dust removing mechanism 21 has a removing key, and can be operated manually or automatically by operating the paper dust removing key. When automatically operating the paper dust removal mode, it may be set to always operate during the printing operation, or may be set to operate at regular intervals during the printing operation. good.

Next, the operation of the above configuration will be described. Impression cylinder 3
Is located at a standby position, and a stencil sheet which has been made is mounted on the outer peripheral surface of the plate cylinder 1. In this state,
When the print start key is turned on, the impression cylinder 3 is moved to the pressure contact position, the impression cylinder 3 is pressed against the transfer cylinder 2 by a desired pressure force, and the main motor is driven, as shown by the arrow in FIG. The plate cylinder 1, the transfer cylinder 2 and the impression cylinder 3 are rotated in the same direction and at the same peripheral speed at the places where they are close to and pressed against each other.

When the squeegee roller 7 is moved from the standby position to the pressing position, the screen 6 bulges outward and is pressed against the transfer cylinder 2, and the ink 5 passing through the perforations of the stencil sheet is transferred by the pressing force. The ink image is transferred onto the cylinder 2, that is, onto the transfer sheet 11 of the transfer cylinder 2. Further, at a predetermined timing, a paper feeding unit 13 is provided between the transfer cylinder 2 and the impression cylinder 3.
The printing paper 14 is conveyed from this, the ink image of the transfer sheet 11 of the transfer cylinder 2 is transferred to the printing paper 14, and the printing paper 14 on which the ink image has been transferred is sent to the paper output unit 15. When such a predetermined number of printing operations are performed, the rotation of the main motor is stopped, the squeegee roller 7 is moved to the pressing position or the standby position, the impression cylinder 3 is moved to the separated position, and the printing mode is completed. I do.

Next, in the printing operation process, when the paper dust removal mode is selected automatically or by the paper dust removal key, as shown in FIG. 28 is turned on, and the cleaning roll 24 is moved from the non-operation position to an operation position where the cleaning roll 24 substantially abuts the transfer sheet 11. Then, the cleaning roll 24 rotates on the transfer sheet 11 following the rotation of the transfer cylinder 2.

The rotation of the cleaning roll 24 also rotates the water supply roll 30, and the water 34 in the water tray 33 is continuously transferred to the water supply roll 30 and the cleaning roll 24 in this order, and is transferred from the cleaning roll 24 to the transfer sheet 11. Water 34 is transferred. The paper dust attached to the transfer sheet 11 floats with the transferred water 34, and the floated paper dust is reversely transferred to the cleaning roll 24 and the water supply roll 30 in order by the delta effect, and the water supply roll 3
The paper powder transferred to 0 is precipitated in the water in the water tray 33. Here, the delta effect refers to a phenomenon in which foreign matter in water is transferred to a small-diameter roll when rolls of different diameters coated with a solution such as water are rotating while rotating substantially against each other. .

That is, paper dust is generated from the printing paper 14 due to friction of the rolls 17, 18, 19 and the like of the paper supply unit 13, and the paper dust attached to the printing surface of the printing paper 14 is When the transfer sheet 1 is pressed against the transfer cylinder 11 directly
Transferred to 1 and attached. The paper powder separated from the printing paper 14 floats in the air and adheres to the transfer sheet 11. Thus, the paper dust attached to the transfer sheet 11 of the transfer cylinder 2 is removed from the transfer sheet 11 by the paper dust removing mechanism 21.

Accordingly, the paper dust adhering to the transfer sheet 11 retains the ink 5 and the predetermined amount of the ink 5 is not transferred to the printing paper 14, so that the image corresponding to the place where the paper dust adheres becomes thin. The paper dust holding a large amount of the ink 5 is transferred to the printing paper 14, and a large amount of the ink 5 of a predetermined amount or more is transferred to the printing paper 14, so that an image corresponding to the portion where the paper dust adheres is more than necessary. , And image deterioration caused by forming an image over a wide area can be prevented. Further, since the paper dust on the transfer cylinder 2 can be removed, the paper dust that is directly transferred from the transfer cylinder 2 to the plate cylinder 1 can be prevented, whereby image deterioration due to the paper dust adhering to the plate cylinder 1 can be prevented. Can be prevented as much as possible.

In the first embodiment, the paper dust removing mechanism 21
Can be switched between an operation state in which paper dust is removed and a non-operation state in which paper dust is not removed, so that the paper dust on the transfer sheet 11 can be removed at any time as needed.
Unnecessary paper dust removing operation can be avoided. Since the switching between the operation state and the non-operation state can be performed by moving the position of the cleaning roll 24, the switching can be easily performed.

In the first embodiment, the paper dust removing mechanism 21
Is arranged in an area on the rotation downstream side from the pressure contact position where the transfer cylinder 2 is pressed against the impression cylinder 3 and on the rotation upstream side from the pressure contact position where the transfer cylinder 2 can be pressed against the plate cylinder 1. Since the paper dust attached to the transfer sheet 11 can be removed before the position where the paper dust is pressed against the plate cylinder 1, the transfer of the paper dust to the plate cylinder 1 can be prevented. Accordingly, paper dust directly transferred from the transfer cylinder 2 to the plate cylinder 1 can be effectively prevented, whereby image deterioration due to the adhesion of the paper dust to the plate cylinder 1 can be further effectively prevented.

In the first embodiment, the paper dust removing mechanism 21
Is a rotatable cleaning roll 24 smaller in diameter than the transfer cylinder 2 and substantially in contact with the transfer sheet 11, and a rotatable water supply roll 30 smaller in diameter than the cleaning roll 24 and substantially in contact with the cleaning roll. Since the lower side of the water supply roll 30 has a water tray 33 in which water is submerged, water in the water tray 33 is transferred to the water supply roll 30 and the cleaning roll 24 in this order, and the transfer sheet of the transfer cylinder 2 is transferred from the cleaning roll 24 to the transfer sheet. The paper dust adhered to the transfer sheet 11 floats with the water transferred onto the transfer sheet 11, and the floated paper dust is reversely transferred to the cleaning roll 24 and the water supply roll 30 in the order of the delta effect. The paper dust transferred to the water tray 33 is settled in the water in the water tray 33, thereby removing the paper dust.
The paper dust can be effectively removed without causing any damage to the transfer sheet 11.

In the first embodiment, the water supply roll 30
The squeegee roll 38, whose gap with the water supply roll 30 is adjustable, is provided at a position near the cleaning roller 24 and at a position upstream of the rotation position where the cleaning roll 24 substantially abuts. Since the thickness can be controlled by adjusting the gap amount of the squeegee roll 38, the thickness of the water transferred to the cleaning roll 24 can be adjusted to a desired thickness. Further, since the squeegee roll 38 is smaller in diameter than the cleaning roll 24, the paper powder that has not been separated from the water supply roll 30 into the water of the water tray 33 is transferred to the squeegee roll 38 by the delta effect. The outer peripheral surface of the supply roll 30 can be kept clean.

In the first embodiment, since the water amount sensor 37 is provided and the amount of the water 34 stored in the water tray 33 is controlled to be always within a predetermined range, the water 34 in the water tray 33 runs short. No spillage occurs due to excessive water 34. Further, although the cleaning roller 24 is configured to rotate following the transfer cylinder 2, the cleaning roller 24 may be configured to rotate by the rotation force of the drive motor.

FIG. 3 is a schematic configuration diagram of a paper dust removing mechanism 21A according to a second embodiment of the present invention. In FIG. 3, the paper dust removing mechanism 21A of the second embodiment is located near the transfer cylinder 2 similarly to the first embodiment, and the transfer cylinder 2 is
The transfer cylinder 2 is constituted by a brush 50 disposed in an area downstream of the pressure contact position where the transfer cylinder 2 is pressed against the plate cylinder 1 and in the area upstream of the pressure contact position where the transfer cylinder 2 can be pressed against the plate cylinder 1. The brush 50 includes a base portion 51 fixed at a predetermined position in the apparatus main body S and a large number of flockings 52 planted on the base portion 51. The large number of flockings 52 is applied to the transfer sheet 11 of the transfer cylinder 2. Has been abutted. The base portion 51 is made of, for example, ABS resin, and the flocking 52 is made of, for example, nylon.

According to the second embodiment, the paper dust adhered to the transfer sheet 11 of the transfer cylinder 2 is removed from the transfer sheet 11 by being scraped off by the brush 50.
Further, in the second embodiment, since the paper dust removing mechanism 21A is the brush 50, the structure is simple and can be manufactured at low cost.

The brush 50 may be configured to be movable between a position where the brush 50 contacts the transfer sheet 11 and a position where the brush 50 separates.
With this configuration, the paper dust on the transfer sheet 11 can be removed as needed at any time, so that unnecessary paper dust removal operation can be avoided.

FIG. 4 is a schematic configuration diagram of a paper dust removing mechanism 21 'according to a third embodiment of the present invention. In FIG. 4, an ink removing means 60 is added to the paper dust removing mechanism 21 'of the first embodiment in the paper dust removing mechanism 21' of the third embodiment. The ink removing means 60 is constituted by a blade 61 which comes into contact with the outer peripheral surface of the cleaning roll 24. The blade 61 is made of, for example, urethane rubber, and is installed with no gap with respect to the cleaning roll 24. Since other configurations are the same as those of the first embodiment, the same portions are denoted by the same reference numerals in the drawings, and description thereof will be omitted.

In the third embodiment, the same operation and effect as those in the first embodiment can be obtained. In addition, when the ink 5 attached to the transfer sheet 11 of the transfer cylinder 2 is transferred to the cleaning roll 24, the transferred ink 5 is scraped off by the blade 16, so that the ink 5 transferred to the cleaning roll 24 is removed. Image deterioration caused by retransfer to the transfer sheet 11 can be prevented.

FIG. 5 is a schematic diagram of a paper dust removing mechanism 21 ″ according to a fourth embodiment of the present invention. In FIG. 5, the paper dust removing mechanism 21 ″ of the fourth embodiment includes the first dust removing mechanism 21 ″. The ink removing unit 60 ″ is used for the paper dust removing mechanism 21 of the embodiment.
Is added. The ink removing unit 60 ″ includes a cleaning liquid application unit 71 that applies a cleaning liquid to the outer peripheral surface of the cleaning roll 24, a cleaning liquid wiping unit 72 that wipes the cleaning liquid applied to the outer peripheral surface of the cleaning roll 24 by the cleaning liquid application unit 71. It is composed of

The cleaning liquid application section 71 has a rotatable cleaning roll 73 in contact with the cleaning roll 24, and a doctor roll 74 in close proximity to the cleaning roll 73 via a predetermined gap. The cleaning liquid is stored in a space above the roll 74.
The cleaning liquid wiping unit 72 has a curved pad portion 75 disposed downstream of the cleaning liquid application unit 71 and in the vicinity of the cleaning roll 24. Cleaning cloth 7 passed between winding unit 77
8 is hung. The take-up section 77 is rotated by the rotational force of a cloth moving motor (not shown). Since other configurations are the same as those of the first embodiment, the same portions are denoted by the same reference numerals in the drawings, and description thereof will be omitted.

In the fourth embodiment, the same operation and effect as in the first embodiment can be obtained. In addition, the ink 5 attached to the transfer sheet 11 of the transfer cylinder 2 is transferred to the cleaning roll 24. On the other hand, cleaning roll 2
The cleaning roll 73 rotates following the rotation of the cleaning roller 4, and the cleaning liquid is transferred to the cleaning roll 24 by this rotation. The transferred cleaning liquid dissolves or swells the ink 5, and the dissolved or swelled ink 5 is wiped off with the cleaning cloth 78 together with the cleaning liquid. Therefore, the ink 5 transferred to the cleaning roll 24 is
Image deterioration caused by re-transfer to the image can be prevented.

In the third embodiment, the ink removing means 60 is constituted by a blade 61, and in the fourth embodiment, the ink removing means 60 "is constituted by a cleaning liquid application section 71 and a cleaning liquid wiping section 72. However, the cleaning roll 24
Any configuration that can remove the upper ink 5 may be used. However, when the ink removing means 60 is configured by the blade 61, the configuration is simple and can be manufactured at low cost. Further, when the ink removing means 60 ″ is composed of the cleaning liquid application section 71 and the cleaning liquid wiping section 72, the ink 5 can be removed without damaging the cleaning roll 24 at all.
Further, although the cleaning liquid application section 71 applies the cleaning liquid by the cleaning roll 73, the cleaning liquid may be applied by spraying.

[0068]

As described above, according to the first aspect of the present invention, since the paper dust removing mechanism for removing the attached paper dust is provided on the transfer sheet side of the transfer cylinder, the paper can be printed directly from the printing paper. Paper dust that is transferred to the transfer sheet of the transfer cylinder or paper dust that floats in the air adheres to the transfer sheet of the transfer cylinder, and the paper dust attached to the transfer sheet is removed from the transfer sheet by the paper dust removal mechanism. Therefore, it is possible to prevent the printed image from deteriorating due to paper dust attached to the transfer sheet of the transfer cylinder. In addition, since the paper dust on the transfer cylinder can be removed, paper dust that is directly transferred from the transfer cylinder to the plate cylinder can be prevented, thereby minimizing the deterioration of a printed image due to the paper dust adhering to the plate cylinder. Can be prevented.

According to the second aspect of the present invention, the paper dust removing mechanism is configured to be switchable between an operating state for removing paper dust and a non-operating state for not removing paper dust. Since the paper dust on the transfer sheet can be removed accordingly, unnecessary paper dust removal operation can be avoided.

According to the third aspect of the present invention, the paper dust removing mechanism is provided at a position downstream of the pressing position where the transfer cylinder presses against the impression cylinder and at a position upstream of the pressing position where the transfer cylinder can press against the plate cylinder. Since the paper dust adhered to the transfer sheet of the transfer cylinder can be removed in front of the position where it is pressed against the plate cylinder, the paper dust can be effectively prevented from being transferred to the plate cylinder. The deterioration of the printed image due to the adhesion of the paper powder to the paper can be more effectively prevented.

According to the fourth aspect of the present invention, the paper dust removing mechanism has a diameter smaller than the diameter of the transfer cylinder and a rotatable cleaning roll which is substantially in contact with the transfer sheet; Has a rotatable water supply roll and a water tray in which the lower side of the water supply roll is submerged, so that the water in the water tray is transferred to the water supply roll and the cleaning roll in order to remove paper dust, The paper dust attached to the transfer sheet floats with the water transferred from the cleaning roll to the transfer sheet of the transfer cylinder, and the floated paper dust is reversely transferred to the cleaning roll and the water supply roll in order by the delta effect, Since the paper dust transferred to the water supply roll is precipitated in the water in the water tray, it does not damage the transfer sheet of the transfer cylinder. You can remove the paper dust without.

According to the fifth aspect of the present invention, the squeegee roll capable of adjusting the gap with the water supply roll is provided at a position close to the water supply roll and upstream of the rotation position where the cleaning roll substantially abuts. With the provision, the water film thickness of the water supply roll can be controlled by adjusting the gap amount of the squeegee roll, so that the water film thickness transferred to the cleaning roll can be adjusted to a desired film thickness.

According to the sixth aspect of the present invention, the cleaning roll is movable between an operation position where the cleaning cylinder substantially contacts the transfer sheet and a non-operation position where the transfer cylinder is separated from the transfer sheet. Since the switching between the state and the non-operation state can be performed by moving the position of the cleaning roll, the switching can be easily performed.

According to the seventh aspect of the present invention, since the paper dust removing mechanism is a brush contacting the transfer sheet of the transfer cylinder,
Since the paper dust is removed by scraping the paper dust attached to the transfer sheet with a brush, the removal of the paper dust can be realized with a simple configuration and at low cost.

According to the eighth aspect of the present invention, since the paper dust removing mechanism has the ink removing means for removing the ink attached to the cleaning roll, when the ink on the transfer sheet is transferred to the cleaning roll, the cleaning roll is removed. Since the ink transferred to the transfer sheet is removed by the ink removing unit, it is possible to prevent the image from being re-transferred to the transfer sheet and causing image deterioration.

According to the ninth aspect of the present invention, since the ink removing means is constituted by the blade abutting on the outer peripheral surface of the cleaning roll, the ink can be removed by scraping off the ink transferred by the cleaning roll with the blade. Therefore, ink removal can be realized with a simple configuration and at low cost.

According to the tenth aspect of the present invention, the ink removing means wipes off the cleaning liquid applied to the outer peripheral surface of the cleaning roll by the cleaning liquid application unit for applying the cleaning liquid to the outer peripheral surface of the cleaning roll. Since the cleaning liquid wiping portion is provided, the ink is dissolved or swelled with the applied cleaning liquid, and the dissolved or swollen ink is wiped off together with the cleaning liquid, thereby preventing the cleaning roll from being damaged. .

[Brief description of the drawings]

FIG. 1 shows a first embodiment of the present invention, and is a schematic configuration diagram of a main part of a stencil printing apparatus.

FIG. 2 shows the first embodiment of the present invention and is a schematic configuration diagram of a paper dust removing mechanism.

FIG. 3 is a schematic configuration diagram of a paper dust removing mechanism according to a second embodiment of the present invention.

FIG. 4 is a schematic configuration diagram of a paper dust removing mechanism according to a third embodiment of the present invention.

FIG. 5 is a schematic configuration diagram of a paper dust removing mechanism according to a fourth embodiment of the present invention.

FIG. 6 is a schematic configuration diagram of a main part of a conventional stencil printing apparatus.

FIG. 7 is a schematic configuration diagram of a main part of a conventional stencil printing machine, showing a state in which generated paper dust adheres to a transfer cylinder and the like.

[Explanation of symbols]

 Reference Signs List 1 plate cylinder 2 transfer cylinder 3 impression cylinder 5 ink 11 transfer sheet 14 printing paper 21, 21A, 21 ', 21 "paper dust removing mechanism 24 cleaning roll 30 water supply roll 33 water tray 34 water 38 squeegee roll 50 brush 60, 60 ″ Ink removing means 61 Blade 71 Cleaning liquid application unit 72 Cleaning liquid wiping unit

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hiroyuki Sugimoto 2-20-15 Shimbashi, Minato-ku, Tokyo R-Science Industry Co., Ltd. F-term (reference) 2C250 FA09 FB10 FB18

Claims (10)

[Claims] 1. A stencil sheet perforated on the basis of image information is freely attachable to an outer peripheral surface, and a rotatable plate cylinder that supplies ink to the stencil sheet from an inner peripheral surface side, and is synchronized with the plate cylinder. A transfer cylinder having a transfer sheet on the outer peripheral surface on which an ink image is transferred from the stencil sheet pressed and rotated,
In order to transport the printing paper that is rotated in synchronization with the rotation of the transfer cylinder and is guided between the transfer cylinder and the paper discharge side, and to transfer the ink image of the transfer sheet to the printing paper in the transporting process. A stencil printing apparatus comprising: an impression cylinder for applying the printing pressure of claim 1, wherein a paper dust removing mechanism for removing adhering paper dust is provided on the transfer sheet side of the transfer cylinder. 2. The stencil printing machine according to claim 1, wherein the paper dust removing mechanism is switchable between an operating state for removing paper dust and a non-operating state for not removing paper dust. A stencil printing apparatus characterized by the above-mentioned. 3. The stencil printing apparatus according to claim 1, wherein the paper dust removing mechanism is rotated downstream from a pressing position at which the transfer cylinder presses against the impression cylinder, and the transfer is performed. A stencil printing machine characterized in that the cylinder is disposed in an area on the rotation upstream side from a pressure contact position where the cylinder can be pressed against the plate cylinder. 4. The stencil printing apparatus according to claim 1, wherein the paper dust removing mechanism has a diameter smaller than a diameter of the transfer cylinder, and is rotatable cleaning that is substantially in contact with the transfer sheet. Roll and a diameter smaller than the diameter of this cleaning roll,
A stencil printing machine comprising: a rotatable water supply roll substantially in contact with the cleaning roll; and a water tray in which the lower side of the water supply roll is flooded. 5. The stencil printing machine according to claim 4, wherein the water supply roll is located at a position close to the water supply roll and at a rotation position upstream of a rotation position at which the cleaning roll substantially abuts. A stencil roll provided with a squeegee roll capable of adjusting the gap between the stencil printing machine and the stencil roll. 6. The stencil printing apparatus according to claim 4, wherein the cleaning roll is in an operation position where the transfer cylinder is substantially in contact with the transfer sheet, and a non-operation position in which the transfer cylinder is separated from the transfer sheet. A stencil printing apparatus characterized by being movable between and 7. The stencil printing apparatus according to claim 1, wherein the paper dust removing mechanism is a brush that contacts the transfer sheet of the transfer cylinder. 8. The stencil printing apparatus according to claim 1, wherein the paper dust removing mechanism has an ink removing unit that removes ink attached to the cleaning roll. apparatus. 9. The stencil printing apparatus according to claim 8, wherein the ink removing unit is a blade that contacts an outer peripheral surface of the cleaning roll. 10. The stencil printing apparatus according to claim 8, wherein the ink removing unit is configured to apply a cleaning liquid to an outer peripheral surface of the cleaning roll, and the outer peripheral surface of the cleaning roll is formed by the cleaning liquid applying unit. A stencil printing apparatus comprising: a cleaning liquid wiping unit for wiping a cleaning liquid applied to the stencil printing apparatus.