JP2001246825A - Screen printing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a screen printing apparatus capable of properly holding printing paper between a plate cylinder and a paper cylinder to apply printing thereto even if the expanding deformation quantity of the peripheral wall of the plate cylinder due to the inner press roller arranged in the plate cylinder is reduced. SOLUTION: The plate cylinder 14 has a deformable rotary peripheral wall 74 and the inner press roller 18 provided in the plate cylinder. The paper cylinder 20 is provided under the plate cylinder at a predetermined interval and, at a time of printing, printing paper is supplied to the gap between the plate cylinder and the paper cylinder. The plate cylinder 14 is moved toward the paper cylinder 20 by an up and down moving mechanism 96 to fall by a distance L. The inner press roller presses the peripheral wall of the plate cylinder outwardly and the printing paper is fed while held between the plate cylinder and the paper cylinder to be printed. Even if the expanding deformation quantity of the peripheral wall 74 of the plate cylinder 14 is small, the printing paper p can be properly held between the plate cylinder 14 and the paper cylinder 20 to be printed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stencil sheet on which a printing paper is sandwiched between a swelling deformed portion and a press drum by partially expanding the peripheral wall of the drum on which a stencil sheet is wound. The present invention relates to an inner press type stencil printing apparatus that performs stencil printing with a stencil printing machine.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 9-39356 discloses a plate cylinder,
A so-called inner press type stencil printing apparatus including a paper cylinder (corresponding to a backing member) and a middle pressing roller (corresponding to a middle pressing member) is disclosed.

[0003] In such a stencil printing apparatus, a clamp member for clamping a stencil sheet is provided on an outer peripheral portion of a plate cylinder. (Approximately 3 mm). At the time of printing, a part of the peripheral wall is swelled and deformed in the radial direction by pressing the inner peripheral surface of the peripheral wall of the plate cylinder with the intermediate pressing roller, and the printing paper is sandwiched between the swelled deformed portion and the paper cylinder. Stencil printing with. Therefore, the amount of bulging deformation of the peripheral wall due to the intermediate pressing roller is set to about the above-mentioned interval.

[0004]

However, the conventional stencil printing apparatus of the inner press system disclosed in Japanese Patent Application Laid-Open No. 9-39356 and the like sandwiches the printing paper only by expanding and deforming the peripheral wall of the plate cylinder. Therefore, the amount of swelling deformation must be set to a relatively large value, which causes excessive stress to be applied to the stencil paper wound on the peripheral wall, and causes the stencil paper to expand and deform, resulting in poor printing. There were drawbacks.

The present invention has been made in view of such circumstances, and provides a stencil printing apparatus capable of properly sandwiching and printing printing paper even when the amount of bulging deformation of the peripheral wall of the plate cylinder is reduced. It is intended to be.

[0006]

In order to achieve the above object, the present invention provides a plate cylinder provided rotatably and having a stencil wrapped around a peripheral wall on which an ink-permeable region is formed. An intermediate pressing member that is provided inside the plate cylinder, presses a part of the inner peripheral surface of the peripheral wall, and swells and deforms a part of the peripheral wall in a radial direction, and is disposed at a predetermined distance from the plate cylinder. A stencil printing apparatus, comprising: a backing member that performs stencil printing on the printing paper by sandwiching and transporting the printing paper between a part of the peripheral wall that has been swelled and deformed by the intermediate pressing member. A moving means is provided which can move the plate cylinder and the backing member in a direction of relatively approaching and in a direction of separating.

According to the first aspect of the present invention, the moving means moves the plate cylinder and the backing member in a direction of relatively approaching, and relatively presses the backing member and the plate cylinder. Then, while the peripheral wall of the plate cylinder is pressed from the inside by the intermediate pressing member, the printing paper is sandwiched between the plate cylinder and the backing member, and the printing paper is stencil-printed. Therefore, the present invention
Even if the amount of bulging deformation of the peripheral wall of the plate cylinder is reduced, printing can be performed while properly sandwiching the printing paper.

According to the second aspect of the present invention, only the peripheral wall of the plate cylinder composed of the plate cylinder main body and the peripheral wall is moved by the moving means. As described above, according to the present invention, only the peripheral wall, which is lighter than the plate cylinder main body, is moved by the moving means, so that the load on the moving means for moving the plate cylinder can be reduced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a stencil printing apparatus according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is an internal structural diagram of a stencil printing apparatus 10 according to an embodiment of the present invention. Inside the main body 12 of the stencil printing apparatus 10, a plate cylinder 14 is rotatably and vertically movable, and the outer peripheral surface of the plate cylinder 14 holds an end of the stencil sheet at the time of stencil printing. A clamp member 16 is provided. Further, inside the plate cylinder 14, there are disposed an intermediate pressing roller 18 for pressing the inner peripheral surface of the plate cylinder 14, and a doctor roller 19 for uniformly supplying printing ink to the intermediate pressing roller 18. Further, a paper cylinder 20 is disposed immediately below the plate cylinder 14. The paper cylinder 20 is disposed at a position facing the intermediate pressing roller 18, and the pressing operation of the intermediate pressing roller 18 causes the paper cylinder 20 to be compared with the related art. The stencil printing is performed by sandwiching the printing paper P between the printing paper P and a part of the peripheral wall 74 of the plate cylinder 14 where a small amount is swelled and deformed.

[0010] On the upper right side of the main body 12 in FIG.
Is provided. Above the paper feed table 22, there are provided a scraper 24 that feeds out the printing paper P stacked on the paper feed table 22 one by one toward the plate cylinder 14, and a pickup roller 26. Pickup roller 2
6, a pair of upper and lower timing rollers 28 is provided.
It is accurately sent out in conjunction with the rotation of the plate cylinder 14 and the paper cylinder 20. The scraper 24 and the pickup roller 26 have a built-in one-way clutch. When the printing paper P is transported by the timing roller 28, the printing paper P is driven to rotate.

On the upper left side of the plate cylinder 14 in FIG.
A transport belt 32 and a suction unit 34 are provided. The printing paper P is transferred to the plate cylinder 14 by the peeling nail 30.
The printing paper P, which has been separated from the printing paper P, is attracted to the transport belt 32 by the suction unit 34, and then is discharged to the discharge tray 36 by the transport belt 32.

A lid 38 is provided on the upper part of the main body 12. A line image sensor 40 is attached to the back side of the lid 38, and a document separating roller 42 is arranged on the upper surface of the main body 12 facing the line image sensor 40, with the upper part thereof partially protruding from the main body 12. ing. Reference numeral 44 denotes a document table, and a document 46 is transferred from the left side of the lid 38 to the document separation roller 42 using the document table 44.
And the line image sensor 40.

A stencil sheet roll around which a stencil sheet 48 is wound is accommodated in the main body 12 in a rotatable state.
From there, a plate making section 50, a stencil stock box 52, a cutter 54 and the like are provided toward the plate cylinder 14. Furthermore,
On the opposite side of the plate cylinder 14 from the cutter 54, a plate discharging claw 56
Is provided. The plate making section 50 is composed of a thermal head 60 and a platen roller 62 disposed opposite to the thermal head.

The plate cylinder 14 is formed in a cylindrical shape as shown in FIGS. 2 to 4 and has a drum frame 70 disposed therein, a plate cylinder main body 72 for supporting the doctor roller 19 and the like. And a peripheral wall 74 arranged on the outer peripheral portion. The peripheral wall 74 is provided at both ends of the plate cylinder main body 72 (FIGS.
(Only one end is shown in FIG. 4). It is rolled and attached to the outer peripheral edge of a ring-shaped flange 76 disposed at one end.

The peripheral wall 74 is formed by laminating a plurality of flexible screens knitted with a wire such as a stainless steel wire. Further, on the inner surface of the peripheral wall 74, as shown in FIG. 5, an ink-permeable area 74A through which ink passes and an ink non-permeable area 74B through which ink does not pass are formed. The ink dam 7 surrounds the ink passage area 74A.
5 is provided, and the ink weir 75 is formed in a substantially U-shape with the printing start end 74C of the peripheral wall 74 opened. The intermediate pressing roller 18 (see FIG. 1) is pressed against the ink passage area 74A located inside the ink weir 75 in FIG. Thereby, the ink supplied to the intermediate pressing roller 18 is pushed out of the peripheral wall 74 via the ink passage area 74A,
It is supplied to stencil paper.

The drum frame 70 shown in FIG. 2 is supported by the main body 12 of the stencil printing apparatus 10 (see FIG. 1) in a cantilever manner. The doctor roller 19 is attached to the drum frame 70.
Are rotatably supported, and the drum frame 7
0, a vertical movement mechanism 78 of the intermediate pressing roller 18
Is attached.

The vertical moving mechanism 78 includes a cam 80, a cam follower 82, an arm 84, a spring 86, and the like. The cam 80 is disposed in parallel with the rotation axis 77 of the peripheral wall 74, and is supported by the drum frame 70. Fixed to a shaft 88. A gear 90 shown in FIG.
The gear 90 is meshed with a drive gear 92. The drive gear 92 is attached to a shaft 94 that is supported by the drum frame 70, and is meshed with a drive force transmission gear (not shown) provided outside the plate cylinder 14. Therefore, when the rotational force from the driving force transmission gear is transmitted to the driving gear 92 and the driving gear 92 is rotated, the gear 90 is rotated, and the cam 80 is rotated via the shaft 88.
Is rotated.

The cam follower 82 shown in FIG. 2 is rotatably supported on an upper end of an arm 84 formed in an L-shape. The arm 84 has an intermediate bent portion at the shaft 94.
The roller 84 is rotatably supported at the lower end of the arm 84, and the intermediate pressing roller 18 is rotatably supported via a shaft 18A. Further, the arm 84 is urged clockwise in FIG. 2 around the shaft 94 as a support shaft by the urging force of a spring 86 hung between the upper end of the arm 84 and the drum frame 70. The biasing force of the spring 86 presses the middle pressing roller 18 against the inner surface of the peripheral wall 74 and causes the cam follower 82 to move the cam surface 81A of the cam 80.
Is pressed. Therefore, when the cam 80 is rotated,
When the cam follower 82 is moved up and down along the cam surface 81A, the arm 84 is swung, whereby the position where the intermediate pressing roller 18 presses the peripheral wall 74 and
It is moved up and down between the positions where it is withdrawn from.

Incidentally, the drum frame 70 includes:
As shown in FIGS. 3 and 4, a vertical movement mechanism (corresponding to a moving means) 96 for moving the peripheral wall 74 up and down, that is, a mechanism for moving the plate cylinder 14 in a direction of moving toward and away from the paper cylinder 20 is attached. Have been. This vertical movement mechanism 96 is
0, a cam follower 98, a plate cylinder support plate 100, and the like.

The cam follower 98 is rotatably supported on the inner surface of the plate cylinder support plate 100 as shown in FIG. 4, and is in contact with a cam surface 81B formed on the cam 80. The plate support plate 100 has a through hole 10 formed in the center thereof.
A shaft 88 of the plate cylinder main body 72 (see FIG. 2) is disposed through the shaft 1 so as to be free from the shaft 88. As shown in FIG. 3, three driven rollers 102, 102, and 102 are rotatably supported at equal intervals on the outer peripheral portion of the plate cylinder support plate 100.
As described above, is in contact with the flat surface 76A on the inner periphery of the flange 76. Further, the plate cylinder support plate 100 is provided with the shaft 94 shown in FIG.
It is supported swingably.

With such a support structure, the plate cylinder support plate 1 is provided.
Since the rotation of the outer peripheral wall 74 is regulated by the shaft 94, the peripheral wall 74 is not driven to rotate even when the peripheral wall 74 is rotated, and when the cam 80 is rotated, the cam follower 98 is moved to the cam surface 81.
Since it moves up and down along B, it swings up and down around the shaft 94 as a fulcrum. Thereby, the peripheral wall 74 is pushed by the driven roller 102 of the plate cylinder support plate 100 and is moved in the vertical direction.

On the other hand, the drive gear 92 is integrally formed with a gear 104 for rotating the peripheral wall 74. The gear 104 is engaged with a gear 77 formed on the inner peripheral surface of the flange 76. Therefore, when the drive gear 92 is rotated, the rotational force is transmitted from the gear 104 to the flange 76 via the gear 90, so that the peripheral wall 74 is rotated. In addition, since the plate cylinder 14 of this example is rotated clockwise in FIG. 3 during stencil printing, the rotation direction of the drive gear 92 is clockwise in FIG. Thus, the cam 80 is rotated counterclockwise in FIG.

The paper cylinder 20 shown in FIG. 2 is a cylinder or a columnar body having the same diameter as the plate cylinder 14 and is provided in parallel with the plate cylinder 14 at a predetermined distance from the plate cylinder 14. The printing drum 20 is rotated by a synchronous rotation driving device (not shown).
4 is rotated counterclockwise in FIG. 2 around the rotation axis 20A. The paper cylinder 20 has a concave portion 21 formed on an outer peripheral portion corresponding to the clamp member 16 of the plate cylinder 14 for preventing interference with the clamp member 16.

Next, the operation of the plate cylinder 14 and the paper cylinder 20 configured as described above will be described with reference to FIGS. FIG. 6A shows a state where the stencil sheet 48 is wound around the plate cylinder 14 and the printing paper P is conveyed to the timing roller 28, that is, a state of a reference position (printing start position).

In this state, the plate cylinder 14 and the paper cylinder 20
Are separated from each other, and thereafter, when the plate cylinder is rotated clockwise in FIG. 6 and the paper cylinder 20 is rotated counterclockwise, as shown in FIG. Then, the printing paper P is sent out from the timing roller 28.
Thereafter, the peripheral wall 74 of the plate cylinder 14 is moved up and down by a vertical movement mechanism 96 (FIG. 4).
Swings downward about the shaft 94 by the action of
As a result, the peripheral wall 74 moves downward by an amount L, and
Is pressed.

Thereafter, the printing paper P is transferred to the plate cylinder 14 and the paper cylinder 20.
Immediately before the sheet is sandwiched between
As shown in (C), the roller 18 is moved downward by the action of the vertical moving mechanism 78 (see FIG. 2) of the intermediate pressing roller 18. By this operation, a part of the inner side surface of the peripheral wall 74 is pressed by the intermediate pressing roller 18, and a part of the peripheral wall 74 is slightly expanded and deformed and pressed against the paper cylinder 20. As a result, the printing pressure on the printing paper P is set, and the printing paper P is printed as shown in FIG. 7D while maintaining this state.

Therefore, in this embodiment, even if the amount of bulging of the peripheral wall 74 by the intermediate pressing roller 18 is reduced, the shortage is compensated for by the downward movement of the plate cylinder 14, so that the printing paper P And print the printing paper. Accordingly, the printing paper P can be printed without applying excessive stress to the stencil sheet 48, that is, without forcibly deforming the stencil sheet 48.

The vertical movement mechanism 96 of the present embodiment has a peripheral wall 74 (and a flange 7) that is lighter than the plate cylinder main body 72.
6) Only the vertical movement mechanism 9
6 can be reduced.

When printing of the first printing paper P is completed,
First, the intermediate pressing roller 18 is moved up as shown in FIG. 7 (E) and retreats from the peripheral wall 74.
It is moved upward as shown in FIG. The above is the operation of the plate cylinder 14 and the cylinder 20 for printing one sheet of printing paper P.
In the case of continuously printing the second and subsequent print sheets P, the operations shown in FIGS. 6 and 7 (B) to (F) are repeatedly performed.

In the stencil printing apparatus 10 according to the present embodiment, the structure in which the plate cylinder 14 is first moved down and then the intermediate pressing roller 18 is moved down as shown in FIG. 6 is described. Instead, as shown in FIGS. 8 and 9 (A), (B) and (C), printing is performed by simultaneously lowering and moving the plate cylinder 14 and the intermediate pressing roller 18, and thereafter, FIG. The structure in which the plate cylinder 14 and the intermediate pressing roller 18 are simultaneously moved up as shown in FIG.

In the stencil printing apparatus 10 of the present embodiment, only the plate cylinder 14 side has a movable structure. However, the present invention is not limited to this. Only the paper cylinder 20 side may have a movable structure. Both of the paper cylinders 20 may have a movable structure.

Further, as in the present embodiment, the structure in which the plate cylinder 14 is moved and pressed against the paper cylinder 20 is used for multicolor printing in which one paper cylinder 20 and a plurality of plate cylinders 14 are provided. Stencil printing apparatus. That is, in the case of such a multicolor printing apparatus, one paper cylinder 20 has a movable structure,
When the plurality of plate cylinders 14 have a fixed structure, not only does the movable structure of the paper cylinder 20 become complicated, but also it becomes difficult to control the movement timing of the paper cylinder 20 with respect to the plurality of plate cylinders 14. On the other hand, the structure and control for moving the plurality of plate cylinders 14 with respect to one paper cylinder 20 are such that the plate cylinder 14 is directed toward the paper cylinder 20 only when printing paper P is printed by the plate cylinder 14. It's very easy to move.

Further, in the present embodiment, since the amount of bulging deformation of the peripheral wall 74 can be minimized, the ends of the rectangular peripheral wall 74 (see FIG. 5) are connected to each other via a spring. In addition to the peripheral wall 74 formed in a cylindrical shape, a peripheral wall previously formed in a cylindrical shape can also be applied.

[0034]

As described above, according to the stencil printing apparatus of the present invention, there is provided moving means for relatively moving the plate cylinder and the backing member in the direction of contact and separation. Since the pressing is performed with the backing member relatively close to each other, the printing paper can be properly sandwiched and printed even if the amount of bulging deformation of the peripheral wall of the plate cylinder is reduced.

Further, according to the present invention, only the peripheral wall of the plate cylinder composed of the plate cylinder main body and the peripheral wall is moved by the moving means, so that the plate cylinder is moved by the moving means. The load can be reduced.

[Brief description of the drawings]

FIG. 1 is an internal configuration diagram of a stencil printing apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged view showing a plate cylinder and a paper cylinder of the stencil printing machine shown in FIG.

FIG. 3 is a structural view showing a mechanism for moving the plate cylinder up and down.

FIG. 4 is a sectional view taken along line 4-4 in FIG. 3;

FIG. 5 is a development view of a peripheral wall of the plate cylinder.

FIG. 6 is a view for explaining the operation of a plate cylinder and a paper cylinder.

FIG. 7 is a view for explaining the operation of a plate cylinder and a paper cylinder.

FIG. 8 is a view for explaining another operation of the plate cylinder and the paper cylinder.

FIG. 9 is a view for explaining another operation of the plate cylinder and the paper cylinder.

[Explanation of symbols]

Reference numeral 10: stencil printing machine, 14: plate cylinder, 18: middle press roller, 20: paper cylinder, 72: plate cylinder body, 74: peripheral wall, 76 ...
Flange, 78, 96: Vertical movement mechanism, 80: Cam, 8
2, 98: cam follower, 84: arm, 100: plate cylinder support plate

Claims (2)

[Claims] A stencil paper is wound around a peripheral wall provided with an ink-permeable area and rotatably provided, and a plate cylinder provided inside the plate cylinder and having an inner peripheral surface of the peripheral wall. An intermediate pressing member that presses a part of the peripheral wall to bulge and deform a part of the peripheral wall in a radial direction; A backing member for performing stencil printing on the printing paper by transporting the printing paper between the unit and the unit, in a stencil printing apparatus, wherein the plate cylinder and the backing member are relatively approached. A stencil printing apparatus characterized in that a stencil printing apparatus is provided with a moving means capable of moving in a direction and a direction away from the stencil. 2. The plate cylinder includes a plate cylinder main body and the peripheral wall disposed on an outer peripheral portion of the plate cylinder main body. The plate cylinder main body is fixed to a stencil printing apparatus main body, and the peripheral wall is 2. A stencil printing apparatus according to claim 1, wherein said moving means is moved in said direction by said moving means.