JP2003237208A - Stencil printing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stencil printing apparatus having a blower means capable of preventing not only generation of curling-up but also generation of downward curling. <P>SOLUTION: The stencil printing apparatus is equipped with a plate cylinder 2 for taking up a master 14, a press roller 10 for pressing paper P to the master 14 on the plate cylinder 2, a peel 26 having blower means 28 for sending air to the gap between the master 14 and the leading end of the paper P and peeling the paper P from the master 14, and an auxiliary blow means 35 for sending air to the plate cylinder 2 from the press roller 10. <P>COPYRIGHT: (C)2003,JPO

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 which winds by printing a master made on a peripheral surface of a plate cylinder.

[0002]

2. Description of the Related Art A rotatable plate cylinder formed by winding a plurality of layers of mesh screens of resin or metal mesh on a peripheral surface of a porous support plate which is a porous support cylinder, and a thermoplastic resin film (thickness). A thermoplastic resin film of a master using a master having a laminated structure in which Washi fibers or synthetic fibers or a mixture of Washi fibers and synthetic fibers are pasted together. A sheet that is heated and perforated by a thermal head or the like, and then wound around a plate cylinder and supplied from the paper feed unit by a pressing unit such as a press roller while supplying ink from an ink supply unit provided inside the plate cylinder. Is continuously pressed against the master on the outer circumference of the plate cylinder to cause ink to seep out from the plate cylinder holes and master holes and to transfer to the paper for printing. Thermal digital stencil printing apparatus is generally known.

In a stencil printing machine using a press roller as such a pressing means, a peeling claw is used to peel off the paper stuck to the master on the outer peripheral surface of the plate cylinder by the adhesive force of the ink supplied from the inside of the plate cylinder. It is used. The peeling claw is generally made of resin and has a width of about 20 mm and has a sharply pointed tip portion, and a plurality of the peeling claws are arranged in the axial direction of the plate cylinder. Each peeling nail is
The leading edge is inserted between the master and the paper lifted from the master by the waist of the master to separate the paper.

However, at the time of printing in a high temperature environment where the fluidity of the ink is improved, the amount of ink that oozes out from the master perforated portion through the plate cylinder opening portion increases, and in particular there is a solid image portion at the leading edge of the image. In addition, when the printing speed is high, etc., the adhesive force of the ink increases and the time until the leading edge of the paper pressed by the press roller to the master reaches the peeling claw becomes short, and the floating amount of the paper decreases. As a result, the leading edge of the sheet cannot be lifted from the master only by the user's waist. In this state, the peeling claw cannot be inserted between the sheet and the master, so that the sheet is not peeled by the peeling claw and is stuck to the plate cylinder and is not discharged, so-called roll-up occurs.

Further, the thermoplastic resin film (generally polyester or polyethylene terephthalate resin) constituting the master is a high insulator, and is a high insulator in a low temperature environment where static electricity is difficult to escape. There is a problem that static electricity generated due to contact between the sheet and the sheet is accumulated, the sheet is more likely to stick to the master, and the sheet is rolled up. Therefore, in order to assist the peeling of the paper by the peeling claw, a technique is provided in which a blowing unit is provided near the peeling claw to blow air toward the plate cylinder, and the leading end of the paper is lifted from the master to peel the paper. It is disclosed in Japanese Patent No. 2598790.

[0006]

However, in the technique disclosed in the above publication, the air volume of the air blown from the air blowing means is set assuming that the conditions are the worst, so that it is very large, and the paper is thin and extremely thin. If the paper itself is weak and there is no image at the leading edge of the paper, the paper is bent downward by the air blown from the air blower, and the paper is ejected under the pressure between the press roller and the paper ejection conveyor. There is a problem that it is not done, so-called winding down.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to provide a stencil printing apparatus which is provided with an air blowing means and which can prevent the roll-up from occurring and also prevent the roll-down from occurring.

[0008]

The invention according to claim 1 is
A plate cylinder around which the master is wound, a press roller that presses a sheet against the master on the plate cylinder, and a blower that blows air between the master and the leading edge of the sheet. A stencil printing machine including a peeling member for peeling a sheet is characterized by including an auxiliary blowing unit that blows air from the press roller side toward the plate cylinder side.

According to a second aspect of the present invention, in the stencil printing apparatus according to the first aspect, there is further provided a conveyor belt for conveying the sheet separated from the master, and a suction fan for sucking the sheet on the conveyor belt. It is characterized in that it is provided with a sheet discharging and conveying member, and the suction fan functions as the auxiliary air blowing means.

According to a third aspect of the present invention, in the stencil printing apparatus according to the second aspect, there is further provided an air volume adjusting member for adjusting the air volume of the suction fan which functions as the auxiliary air blowing unit.

According to a fourth aspect of the present invention, in the stencil printing machine according to any one of the first to third aspects, a stencil printing device further has a paper thickness detecting means for detecting the thickness of the paper. It is characterized in that the air volume of the auxiliary blowing means is increased as the thickness of the sheet becomes thinner.

According to a fifth aspect of the present invention, in the stencil printing apparatus according to any one of the first to fourth aspects, the stencil image amount detection for detecting the stencil image amount formed on the master is further performed. Means for increasing the air volume of the auxiliary air blowing means as the plate-making image amount decreases.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic front view of the essential parts of a stencil printing machine adopting the first embodiment of the present invention. In the figure, a stencil printing machine 1 has a plate cylinder 2 which is rotationally driven by a plate cylinder driving means (not shown) at a substantially central portion of an apparatus body (not shown). The plate cylinder 2 includes a porous support plate 2a having both side edges attached to respective peripheral surfaces of a pair of flanges (not shown), and a mesh screen (not shown) wound around the outer periphery of the porous support plate 2a in a plurality of layers. The porous support plate 2a is formed with an opening having a plurality of openings 2b. The non-opening portion of the porous support plate 2a is provided with a stage portion 3 which is a plane along one generatrix of the plate cylinder 2, and is rotatably supported on the stage portion 3 by a support shaft 4a. A clamper 4 is provided. Clamper 4
Is opened and closed by opening and closing means (not shown) when the plate cylinder 2 occupies a predetermined position.

Ink supply means 5 is arranged inside the plate cylinder 2. The ink supply means 5 has an ink supply pipe 6, which also serves as a spindle of the plate cylinder 2, an ink roller 7, a doctor roller 8 and the like. The ink supply pipe 6 is provided between a pair of flanges (not shown), and rotatably supports each flange via a bearing (not shown). An ink pump and an ink pack (not shown) are connected to the ink supply pipe 6, and a plurality of inks in the ink pack (not shown) are provided in the ink supply pipe 6 by the operation of the ink pump (not shown).
It is supplied to the inside of the plate cylinder 2 from a.

The ink roller 7 is rotatably supported between a pair of side plates (not shown) fixed to the ink supply pipe 6 and disposed between a pair of flanges (not shown). It is rotationally driven in the same direction in synchronization with the body 2. The ink roller 7 is arranged at a position where a slight gap is generated between the peripheral surface of the ink roller 7 and the inner peripheral surface of the plate cylinder 2.

A doctor roller 8 is arranged near the ink roller 7. The doctor roller 8 is also rotatably supported between the same side plates (not shown) as the ink roller 7, and is rotationally driven in the opposite direction in synchronization with the ink roller 7 by a rotational driving means (not shown). The doctor roller 8 is arranged at a position where a slight gap is formed between the peripheral surface of the doctor roller 8 and the peripheral surface of the ink roller 7.

A space having a wedge-shaped cross section is formed in the vicinity of the ink roller 7 and the doctor roller 8, and an ink reservoir 9 is formed by accumulating the ink supplied from the ink supply hole 6a in this space. The ink in the ink pool 9 is supplied in a thin layer on the peripheral surface of the ink roller 7 when passing through the vicinity of the ink roller 7 and the doctor roller 8, and the plate cylinder 2 is pressed by the press roller 10 described later. At this time, the peripheral surface of the ink roller 7 and the plate cylinder 2
It is supplied to the inner peripheral surface of the plate cylinder 2 by making contact with the inner peripheral surface of the plate cylinder 2.

A press roller 10 is arranged below the plate cylinder 2. The press roller 10 has a length substantially the same as the axial length of the plate cylinder and is formed by winding an elastic body such as rubber around the core portion 10a. The press roller 10 has one end of a pair of press roller arms 11 at both ends of the core portion 10a. Each is rotatably supported between them. The pair of press roller arms 11, which are plate-shaped members, have their other ends fixed to a press roller shaft 12 that is rotatably supported by a device body (not shown), and are integrated by a press roller swinging device (not shown). Is oscillated. This swing causes the press roller 10 to separate its peripheral surface from the outer peripheral surface of the plate cylinder 2.
And the pressing position where the peripheral surface thereof is brought into pressure contact with the outer peripheral surface of the plate cylinder 2 with a predetermined pressing force.

A master storage member 13 is arranged on the upper right side of the plate cylinder 2. The master storage member 13 is provided on each of a pair of side plates (not shown) of the main body of the apparatus, and the core portion of the master roll 14a is formed by winding a master 14 formed by bonding a thermoplastic resin film and a porous support in a roll shape. 14b is rotatably and detachably supported.

A platen roller 15 is arranged on the left side of the master storage member 13. The platen roller 15 is formed such that its axial length is substantially the same as the width of the master 14, and is rotatably supported between side plates (not shown) of the apparatus main body. The platen roller 15 receives a driving force from a stepping motor (not shown) and is rotationally driven in the clockwise direction in FIG.

A thermal head 16 is arranged below the platen roller 15. The thermal head 16 is formed such that its width is larger than the axial length of the platen roller 15, and a plurality of heating elements are arranged on the upper surface thereof. The thermal head 16 is urged by an urging means (not shown) so that the surface of the heating element is brought into pressure contact with the platen roller 15, and the operation of each heating element is individually controlled by a thermal head driver (not shown).

A cutting means 17 is arranged to the left of the platen roller 15 and the thermal head 16. The cutting means 17 is fixed to an apparatus main body (not shown) and has a lower blade 17a whose width is formed longer than the width of the master 14, and the lower blade 1a.
This is a well-known configuration having an upper blade 17b rotatably provided while moving in the width direction of the master 14 on 7a.

A master transfer roller pair 18 is arranged on the left side of the cutting means 17. Master transport roller pair 18
Has a driving roller 18a and a driven roller 18b which are both rotatably supported between side plates (not shown),
A drive roller 18a that is rotationally driven by a master transport drive unit (not shown) and a driven roller 18 that is pressed against the drive roller 18a.
The master 14 is sandwiched by b and conveyed. To the left of the master transport roller pair 18, the master transport roller pair 1
A guide plate 19 that guides the master 14 conveyed by 8 to the plate cylinder 2 is provided. The guide plate 19 is fixed between side plates (not shown).

At the lower right of the plate cylinder 2, a pair of registration rollers 2
0 is set. A driving roller 20a and a driven roller 20 both of which are rotatably supported between side plates (not shown).
The pair of registration rollers 20 having a position b includes a sheet P fed from a sheet feeding tray (not shown) by a driving roller 20a that is rotated by receiving a driving force from a registration driving unit (not shown) and a driven roller 20b that is pressed against the driving roller 20a. After being temporarily stopped, it is fed between the plate cylinder 2 and the press roller 10 at a predetermined timing.

A sheet thickness detecting means 21 is arranged near the right side of the registration roller pair 20. The sheet thickness detecting means 21 includes a thickness detector 22, an arm 23, rollers 24 and 2.
It is mainly composed of 5 mag. The thickness detector 22 having a variable resistor inside is fixed to a side plate (not shown),
One end of an arm 23 is attached to the rotary shaft of the variable resistor. A roller 24 is rotatably attached to the other end of the arm 23, and a roller 25 rotatably attached to a side plate (not shown) is disposed below the roller 24. A biasing means (not shown) is attached to the arm 23, and the roller 24 is configured to be constantly in pressure contact with the roller 25 with a predetermined pressure contact force.

According to this structure, the paper P has rollers 24, 25
By being sandwiched between the arms, the arm 23 swings clockwise in FIG. 1 around the rotation axis of the variable resistor, and the rotation value of the rotation axis of the variable resistor changes its resistance value.
As a result, the thickness of the paper P is detected. In this embodiment, when the thickness of the paper P is X mm or more and Y (a value larger than X) mm or less, it is defined as plain paper, when it is less than X mm it is defined as thin paper, and when it exceeds Y mm it is defined as thick paper.

A peeling member 26 is disposed on the lower left side of the plate cylinder 2. The peeling member 26 for peeling the leading end of the paper P from the master 14 on the outer peripheral surface of the plate cylinder 2 has a peeling claw 27 and a peeling fan 28 as a blowing unit. The peeling claw 27 is rotatably supported on the apparatus main body (not shown) by a support shaft 27a. When the peeling claw 27 is swung by a claw swinging device (not shown), the tip portion formed into an acute angle in cross section has a plate cylinder 2. Of the outer peripheral surface of the plate cylinder 2 and a spaced position where the front end of the plate cylinder 2 separates from the outer peripheral surface of the plate cylinder 2. The peeling fan 28 is provided near the peeling claw 27,
It is operated by a blower drive means (not shown). The blown air A from the peeling fan 28 is sent by the peeling claw 27 from the outer peripheral surface of the plate cylinder 2 toward the front end portion of the paper P to be peeled off,
The air volume is set to an air volume that allows the leading edge of the sheet P to float above the outer peripheral surface of the plate cylinder 2 even when a solid image is present near the leading edge of the sheet P.

Below the peeling member 26, a paper discharging and conveying member 29 is provided.
Is provided. The paper discharge conveyance member 29 has a drive roller 30, a driven roller 31, an endless belt 32, a suction fan 33, and the like. A plurality of roller-shaped drive rollers 30 and driven rollers 31 are fixed at predetermined intervals to support shafts 30a and 31a, which are rotatably supported by a not-shown transporting member main body having a box shape with an open top surface. An endless belt 32 is stretched between the corresponding driving roller 30 and driven roller 31. The drive rollers 30 are integrally rotated by the support shaft 30a being driven to rotate by a sheet discharge driving means (not shown).
Is moved in the direction of the arrow. The suction fan 33 is attached to the main body of the transport member and is operated by a fan driving means (not shown). By the rotation of the suction fan 33, a negative pressure is generated in the conveyance member main body, and the paper P conveyed on each endless belt 32 is sucked to each endless belt 32 side. On the left side of the paper discharge transport member 29, a paper discharge tray 34 for stacking the paper P transported by the paper discharge transport member 29 is arranged.

A blower fan 35 as an auxiliary blower is disposed below the press roller 10 and the sheet discharge / conveyance member 29. The blower fan 35 is attached to the apparatus main body via a bracket (not shown), and is operated by a blower fan drive motor 36 which is a variable output motor. The blast B from the blast fan 35 is applied to the peeling claw 27.
The sheet P is sent from the outer peripheral surface of the plate cylinder 2 toward the front end of the sheet P, and the air volume thereof is lifted from the outer peripheral surface of the plate cylinder 2 by the blown air A from the separating fan 28.
The air volume is set so that it is possible to prevent the leading edge of the sheet from slipping under the sheet discharging and conveying member 29. According to an experiment by the present inventors, the air volume of the air blow B is 10 to 10 times that of the air blow A.
It was confirmed that by setting it to 30%, the paper P separated from the outer peripheral surface of the plate cylinder 2 can be satisfactorily delivered to the paper discharge conveyance member 29. In the present embodiment, the output of the blower fan drive motor 36 is changed in three stages, and the blower air amount B is set to 10%, 20% and 30% of the blower air amount 3.
Change in stages.

The operation of the stencil printing machine 1 will be described below based on the above configuration. After the operator sets a document to be printed in the image reading unit (not shown) and then presses the plate making start key on the operation panel (not shown), the image reading unit (not shown) reads the document image. The read image is stored in an image memory (not shown) as an image data signal. Further, the plate cylinder 2 starts to rotate at the same time as the reading operation, and the plate cylinder 2 is rotated at the plate discharging unit (not shown).
The plate ejection operation of the used master from above is performed. Plate cylinder 2
The used master peeled off from above is discarded in a plate discharge box (not shown) provided in the plate discharge section. When the plate discharge operation is completed, the plate cylinder 2 starts to rotate again, and the plate cylinder 2 stops at the plate supply standby position shown in FIG. When the plate cylinder 2 stops at the plate feed standby position, an opening / closing means (not shown) is activated, the clamper 4 is opened, and the stencil printing apparatus 1 is in the plate feed standby state as shown in FIG.

When the stencil printing machine 1 is in the plate feeding standby state,
Subsequently, the plate making operation is performed. When the clamper 4 is opened, a stepping motor (not shown) that rotationally drives the platen roller 15 and the drive roller 18a are rotationally driven, and the master 14 is pulled out from the master roll 14a. Each of the heating elements of the thermal head 16 generates heat based on the image data signal stored in the image memory of the pulled-out master 14, and the surface of the thermoplastic resin film is heat-melted and perforated to form a plate-making image.

The master 14 is transported by the platen roller 15 and the master transport roller pair 18 while being plate-making by the thermal head 16, guided by the guide plate 19 and sent to the opened clamper 4. Then, from the number of steps of the stepping motor (not shown), the master 1
When it is determined that the leading end of 4 has reached a predetermined position where it is clamped by the clamper 4, the opening / closing means (not shown) is actuated to close the clamper 4 and the leading end of the master 14 made on the outer peripheral surface of the plate cylinder 2. Is retained.

After that, the plate cylinder 2 is rotationally driven in the clockwise direction in FIG. 1 at the same peripheral speed as the plate making conveying speed of the master 14.
The winding operation of the master 14 around the plate cylinder 2 is performed. And
When it is determined from the number of steps of the stepping motor (not shown) that the plate making for one plate is completed, the platen roller 15 and the master transport roller pair 18 are stopped from rotating, and the upper blade 17b is rotationally moved to cut the master 14. It The cut master 14 is pulled out by the rotation of the plate cylinder 2, and the winding operation is completed by stopping the plate cylinder 2 at the home position after all the masters 14 are wound on the plate cylinder 2.

When the winding operation is completed, the plate cylinder 2 is rotationally driven in the clockwise direction in FIG. 1 at a low speed, and one sheet P is separated and fed from a sheet feeding section (not shown). The sheet P separated and fed by a separation / conveying member (not shown) has its leading end entered between the rollers 24, 25, whereby the arm 23
Is rotated in the clockwise direction in FIG. 1 by the thickness of the paper P,
The thickness detector 22 detects the thickness of the paper P. The detected thickness of the paper P is sorted by the control means (not shown) into one of plain paper, thin paper, and thick paper, and the information on the thickness of the sorted paper P is stored in the storage means (not shown).

The sheet P, the thickness of which is detected by the sheet thickness detecting means 21, is further conveyed by a separating and conveying member (not shown), and is temporarily stopped in a state where its leading end is in contact with the nip portion of the registration roller pair 20. The temporarily stopped paper P is paired with the registration roller pair 2 at a predetermined timing when the leading edge of the image area of the plate-making master 14 wound around the plate cylinder 2 reaches a position corresponding to the press roller 10.
When 0 is driven to rotate, it is fed between the plate cylinder 2 and the press roller 10.

When the registration roller pair 20 is rotated, the blower drive means, the paper discharge drive means, and the fan drive means (not shown) are activated to drive the peeling fan 28, the paper discharge conveying member 29, and the suction fan 33, respectively. At the same time, the blower fan drive motor 36 operates to send the blower B from the blower fan 35 toward a predetermined position. The output of the blower fan drive motor 36 at this time is determined by the thickness information of the paper P stored in the storage means (not shown). In the present embodiment, when the thickness of the paper P is thick, the air volume of the air blow B is the air flow. When the thickness of the paper P is plain paper, the air volume of the air blow B is 20% of the air volume of the air blow A, and when the thickness of the paper P is thin, So that the air volume of B becomes 30% of the air volume of blast A,
Each is controlled by a control means (not shown). This is because the thinner the thickness of the sheet P, the less the stiffness of the sheet P becomes, so that the sheet P is more likely to be affected by the blown air A and easily slips under the sheet discharge conveying member 29. In addition,
In the case of thick paper, since the paper P itself is stiff, the air volume of the air blow B may be 10% or less of the air volume of the air blow A, or the air blow from the air blow fan 35 may not be performed.

Almost at the same time as the rotation of the drive roller 20a, the press roller oscillating means is actuated to press the outer peripheral surface of the press roller 10 against the outer peripheral surface of the plate cylinder 2 so that the paper P fed by the registration roller pair 20 is transferred. The master 14 wound around the plate cylinder 2 is pressed. By this pressing operation, the press roller 10, the paper P, the master 14 and the plate cylinder 2 are brought into pressure contact with each other, and the ink supplied to the inner peripheral surface of the plate cylinder 2 by the ink roller 7 oozes out from the openings of the plate cylinder 2. Porous support plate 2a, mesh screen (not shown), and master 14
After being filled in the porous support, the sheet is transferred to the sheet P through the perforated portion of the master 14, and so-called plate making is performed.

The paper P on which the image is transferred by printing is
Peeling claw 2 whose tip occupies a close position by claw swinging means 2
7 and the blower A from the peeling fan 28 peels off the outer peripheral surface of the plate cylinder 2 and drops it downward, and the discharged sheet conveying member 29.
Sent to the top. At this time, the blower B 35 is blown from the blower fan 35, so that the sheet P is prevented from sneaking into the lower side of the sheet discharging and conveying member 29, and the occurrence of curling is prevented. The paper P sent to the paper discharge conveying member 29 is conveyed to the left while being attracted to the upper surface of the endless belt 32 by the suction force of the suction fan 33, and is discharged onto the paper discharge tray 34. After that, the plate cylinder 2 is again rotated to the home position and stopped, and the stencil printing apparatus 1 is in a print standby state after the plate-making operation is completed.

After the printing operation is completed, the operator presses a test printing key on the operation panel (not shown) after the printing conditions are set, whereby one sheet of paper P is separated and fed from the paper feeding section. The plate cylinder 2 is rotationally driven at a peripheral speed corresponding to the set printing speed. The thickness of the fed paper P is detected by the paper thickness detecting means 21 in the same manner as at the time of printing, and then the registration roller pair 20 directs the thickness between the plate cylinder 2 and the press roller 10 at a predetermined timing. The image is transferred by being fed and pressed against the outer peripheral surface of the plate cylinder 2 by the press roller 10. The paper P after the image transfer is satisfactorily separated from the outer peripheral surface of the plate cylinder 2 by the interaction of the separation claw 27, the separation fan 28, and the blower fan 35, as in the case of printing, and is discharged via the paper discharge conveyance member 29. The paper is discharged onto the paper tray 34.

When the image position, the image density, etc. are determined by the test printing, the printing start key (not shown) is pressed by the operator after setting these printing conditions and the number of prints, and the paper P is fed from the paper feeding section. Are continuously fed and printing is performed. This printing operation is performed in the same manner as the test printing operation, and the paper P whose thickness is detected by the paper thickness detecting means 21 is fed at a predetermined timing by the registration roller pair 20 and is pressed by the press roller 10 to cause the printing. The image is transferred to one side. The paper P after the image transfer has the peeling claw 27, as in the test printing.
The peeling fan 28 and the blower fan 35 interact with each other so that the peeling fan 28 and the blower fan 35 satisfactorily separate the sheets from the outer peripheral surface of the plate cylinder 2, and the sheets are sequentially discharged onto the sheet discharge tray 34 via the sheet discharge conveying member 29. Then, when the set number of prints is exhausted, the stencil printing machine 1 stops and returns to the print standby state.

At the time of the above-mentioned plate making, test printing, and printing, the blower fan 35 blows the blower air B in an amount corresponding to the thickness of the paper P from the press roller 10 side to the plate cylinder 2 side, so that peeling is performed. The paper P is blown by the blow A from the fan 28.
Can be prevented from sneaking into the lower side of the sheet discharging and conveying member 29,
It is possible to prevent the roll-up and roll-down from occurring and to favorably separate the paper P from the plate cylinder 2.

FIG. 2 shows a second embodiment of the present invention. The stencil printing machine 37 shown in the second embodiment is
Compared with the stencil printing apparatus 1 shown in the above embodiment, instead of the paper discharging and conveying member 29 and the blowing fan 35, the paper discharging and conveying member 3 is used.
8 is the same, and the other configurations are the same.

The paper discharging and conveying member 38 includes a driving roller 39,
Driven roller 40, endless belt 4 as a conveyor belt
1, a suction fan 42, a conveying member main body 43, an air volume adjusting member 44, and the like. The roller-shaped drive roller 39 and the driven roller 40 are rotatably supported by a box-shaped conveyance member main body 43 having a top surface partially open and having an opening 43a on the upstream side in the paper conveyance direction.
A plurality of a belts are fixed to each a at predetermined intervals, and endless belts 41 are stretched between the corresponding driving rollers 39 and driven rollers 40. Each drive roller 3
9, the support shaft 39a is rotationally driven by an unillustrated sheet discharging drive means, so that they are integrally rotationally driven, whereby each endless belt 41 is moved in the arrow direction of FIG.

Suction fan 4 which functions as an auxiliary air blower
2 is attached to the conveyance member main body 43 and is operated by a fan driving means (not shown). Suction fan 42
At a position near the opening 43a of the transport member main body 43 located below the sheet, the leading edge of the sheet P generated by the operation of the suction fan 42 and peeled from the outer peripheral surface of the plate cylinder 2 by the peeling claw 27 from the opening 43a. An air volume adjusting member 44 for adjusting the air volume of the blown air B sent toward
The air flow rate adjusting member 44 is opened and closed steplessly between the fully closed position shown by the solid line in FIG. 2 and the fully opened position shown by the chain double-dashed line in FIG. 2 by adjusting means such as a motor (not shown).

The operation of the stencil printing machine 37 will be described below based on the above configuration. After the operator sets a document to be printed on the image reading unit (not shown) and presses the plate making start key on the operation panel (not shown),
Similar to the first embodiment, the original image reading operation and the plate discharge operation are performed, and the stencil printing apparatus 37 enters the plate supply standby state. After that, the plate making operation and the winding operation are performed similarly to the first embodiment, and the plate-made master 14 is wound on the outer peripheral surface of the plate cylinder 2.

When the winding operation is completed, the plate cylinder 2 is rotationally driven in the clockwise direction in FIG. 2 at a low speed, and at the same time, one sheet of paper P is fed from a paper feeding unit (not shown). The thickness of the separately fed paper P is detected by the paper thickness detecting means 21, and then temporarily stopped by the registration roller pair 20. The detected thickness information of the paper P is stored in a storage unit (not shown).

After that, the registration roller pair 20 operates at a predetermined timing similar to that of the first embodiment, and the paper P is fed between the plate cylinder 2 and the press roller 10.
At this time, the discharge roller driving means and the fan driving means (not shown) are activated to drive the driving roller 39a and the suction fan 4.
2 are respectively driven, and the adjusting means (not shown) is activated to position the air volume adjusting member 44 at a predetermined position. At this time, the predetermined position where the air volume adjusting member 44 is positioned is determined by the thickness information of the paper P stored in the storage means (not shown). In the present embodiment, when the thickness of the paper P is thick, the air blow B is set. When the thickness of the paper P is thin so that the air volume is 10% of the air volume of the air flow A, and when the thickness of the paper sheet P is plain paper, the air volume of the air flow B is 20% of the air volume of the air flow A. The air volume of Blast B is 30 times the air volume of Blast A
The position of the air flow rate adjusting member 44 is controlled by a control unit (not shown) so that the air flow rate becomes%.

Almost at the same time as the operation of the registration roller pair 20, the press roller swinging means is operated to operate the press roller 1
0 is rocked, and the fed paper P is transferred to the master 1 on the plate cylinder 2.
The plate is pressed by being pressed by 4. The sheet P to which the image has been transferred is peeled off from the outer peripheral surface of the plate cylinder 2 by the peeling member 26, and is sent onto the paper discharge conveying member 38. At this time, opening 4
The blown air B is sent from 3a, so that the paper P is prevented from sneaking into the lower side of the paper discharge conveyance member 38, and the occurrence of curling is prevented. The paper P sent to the paper discharge carrying member 38 is carried to the left while being attracted to the upper surface of the endless belt 41 by the suction force of the suction fan 42,
The paper is discharged onto the paper discharge tray 34. After that, the plate cylinder 2 is again rotated to the home position and stopped, and the plate making operation is completed, and the stencil printing apparatus 37 enters a printing standby state.

After the printing operation and after setting the printing conditions, when the operator presses the test printing key on the operation panel (not shown), one sheet of paper P is separated and fed from the paper feeding section and the plate cylinder 2 is set. The test printing is performed by being rotationally driven at the peripheral speed corresponding to the selected printing speed. The fed paper P is fed at a predetermined timing after the thickness thereof is detected in the same manner as when printing the plate, and the image is transferred by being pressed against the outer peripheral surface of the plate cylinder 2. The paper P after the image transfer is
Similar to the plate-making process, the peeling claw 27, the peeling fan 28, and the suction fan 42 interact with each other, so that the peeling is favorably peeled from the outer peripheral surface of the plate cylinder 2 and is discharged onto the paper discharge tray 34 via the paper discharge conveying member 38. .

After the trial printing, the operator presses a print start key (not shown) after setting the printing conditions and the number of prints, so that the paper P is continuously fed from the paper feeding section to perform printing. This printing operation is also performed in the same manner as the test printing operation. The paper P whose thickness has been detected is fed at a predetermined timing by the registration roller pair 20 and is pressed by the press roller 10 to transfer an image to one surface thereof. It The paper P after the image transfer is satisfactorily peeled from the outer peripheral surface of the plate cylinder 2 by the interaction of the peeling claw 27, the peeling fan 28, and the suction fan 42, as in the case of the test printing, and sequentially through the paper discharge conveying member 38. The paper is discharged onto the paper discharge tray 34. Then, when the set number of printed sheets is exhausted, the stencil printing machine 37 stops and returns to the printing standby state.

During the above-mentioned plate making, test printing, and printing, the air flow adjusting member 44 adjusts the air flow generated by the operation of the suction fan 42 to the air flow B of the air volume corresponding to the thickness of the paper P and press roller. Since it is sent from the 10 side to the plate cylinder 2 side, it is possible to prevent the sheet P from slipping under the sheet discharging and conveying member 29 by the blowing air A from the peeling fan 28, and to prevent the winding up and the winding down. Plate cylinder 2
The sheet P can be favorably peeled from the sheet.

In each of the above embodiments, the thickness of the sheet P is detected by the sheet thickness detecting means 21, and the output of the blower fan drive motor 36 and the position of the air volume adjusting member 44 are changed according to the thickness of the sheet P to blow air. By changing the air volume of the blown air B from the fan 35 and the suction fan 42, the downward bending that changes according to the thickness of the paper P, that is, the waist is prevented, and the paper discharge conveying members 29, 38 are prevented from going under. Although it is configured to prevent, a plate-making image amount detection means for detecting the plate-making image amount to be made by the master is connected to an image memory (not shown) that stores the read original image as an image data signal Accordingly, a configuration in which the air volume of the blown air B is changed may be adopted in the same manner as described above. In this case, when the platemaking image amount is large, the airflow of the airflow B is the airflow of the airflow A.
The air flow rate of the blast B is 20% of the air volume of the blast A when the plate-making image amount is medium, and the air volume of the blast B is small when the plate-making image amount is small. Blast A
The air volume is controlled to 30% by the control means (not shown). This is because the smaller the plate-making image amount, the more the paper P from the master 14 on the outer peripheral surface of the plate cylinder 2.
This is because the sheet P is likely to be peeled off, and the sheet P is likely to sneak under the sheet discharge conveying member 29 due to the influence of the blown air A. By arranging both the sheet thickness detecting means and the plate-making image amount detecting means in parallel, it is possible to perform finer control.

In each of the above-mentioned embodiments and modified examples, the air volume of the auxiliary air blowing means which changes according to the thickness of the paper P or the plate-making image amount is set to three stages. Fine control of
It is possible to provide a good stencil printing machine in which the occurrence of winding up and down is surely prevented and defective discharge is eliminated.

[0054]

According to the present invention, the blowing means for blowing air between the master on the outer peripheral surface of the plate cylinder and the leading edge of the sheet, and the auxiliary blowing means for blowing air from the press roller side to the plate cylinder side. By using and, it is possible to provide a stencil printing apparatus capable of preventing the roll-up and roll-down from occurring and favorably separating the paper from the plate cylinder.

Further, by changing the air volume of the auxiliary air blowing means in accordance with at least one of the thickness of the sheet or the amount of plate-making image formed on the master, the sheet goes under the sheet discharging and conveying member. Can be finely prevented, and the occurrence of winding down can be further prevented.

[Brief description of drawings]

FIG. 1 is a schematic front view of a stencil printing machine adopting a first embodiment of the present invention.

FIG. 2 is a schematic front view of a stencil printing machine adopting a second embodiment of the present invention.

[Explanation of symbols]

1,37 Stencil printer 2 plate body 10 Press roller 14 Master 21 Paper thickness detecting means 26 Peeling member 28 Blower (Peeling fan) 35 Auxiliary blower (blast fan) 38 Paper discharge transport member 41 Conveyor belt (endless belt) 42 Suction fan 44 Air volume control member P paper

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B65H 29/54 B41F 33/14 GZ F term (reference) 2C250 EA21 EB35 EB50 3F048 AA05 AB01 BA06 BA14 BA15 BA25 BB02 BB05 CA02 DA06 EB22 EB25 3F049 AA01 FB00 FB03 FC19 LA06 LB03 3F053 AA04 AA19 LA06 LB03

Claims (5)

[Claims] 1. A plate cylinder around which a master is wound, a press roller that presses a sheet against the master on the plate cylinder, and a blowing unit that blows air between the master and the leading edge of the sheet. A stencil printing apparatus comprising: a peeling member that peels the sheet from a master, the stencil printing apparatus including an auxiliary blowing unit that blows air from the press roller side toward the plate cylinder side. 2. A conveyance belt for conveying the sheet peeled from the master, and a sheet discharge conveyance member having a suction fan for sucking the sheet on the conveyance belt, wherein the suction fan serves as the auxiliary blowing unit. The stencil printing machine according to claim 1, which is functional. 3. The stencil printing apparatus according to claim 2, further comprising an air volume adjusting member which adjusts an air volume of the suction fan which functions as the auxiliary air blowing unit. 4. A sheet thickness detecting means for detecting the thickness of the sheet, wherein the air volume of the auxiliary blower means is increased as the thickness of the sheet becomes thinner. The stencil printing apparatus according to any one of 3. 5. A plate-making image amount detecting means for detecting the plate-making image amount formed on the master, and increasing the air volume of the auxiliary blowing means as the plate-making image amount decreases. Any one of claims 1 to 4
The stencil printing machine described in 1.