JPS6028672B2 - stencil printing device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a stencil printing device.

Special competition relating to an application filed by the same applicant as the applicant of the present application
No. 128043 discloses a porous cylindrical printing cylinder that has a stencil stamp attached to its outer peripheral surface and rotates around its central axis;
an ink supply roller that is arranged so that its outer circumferential surface contacts the inner circumferential surface of the cylindrical plate cylinder and rotates around its own central axis; and an ink supply roller that applies a predetermined amount of ink to the outer circumferential surface of the ink supply roller. A stencil printing apparatus has been proposed that includes a coating device and a press roller that rotates about its own central axis and has an outer circumferential surface facing the outer circumferential surface of the cylindrical plate cylinder.

In the stencil printing device that will be proposed in the future, the ink supply roller has its outer circumferential surface in contact with the inner circumferential surface of the cylindrical printing cylinder through a layer of viscous ink, and the ink supply roller has a viscous ink layer. When the cylindrical plate cylinder is driven to rotate, its outer circumferential surface is pressed against the inner circumferential surface of the cylindrical plate 8 with a certain force under the action of force, so that when the cylindrical plate cylinder is driven to rotate, It is supposed to rotate. The circumferential speed of the ink supply roller accompanying the rotation of the cylindrical plate cylinder depends on the hardness of the ink, the thickness of the ink layer supplied to the outer peripheral surface of the ink supply roller, and the inner circumference of the cylindrical plate cylinder. It varies depending on the pressing pressure of the ink supply roller against the surface, the roughness of the inner peripheral surface of the cylindrical plate cylinder and the outer peripheral surface of the ink supply roller, the rotation speed of the cylindrical plate Tsukioka, etc., but the outer peripheral surface of the ink supply roller At the part that contacts the inner circumferential surface of the cylindrical plate, ink is transferred from the outer circumferential surface of the ink supply roller to the inner circumferential surface of the cylindrical plate cylinder, and at the same time, the transferred ink is transferred to the inner circumferential surface of the cylindrical plate cylinder. In order to obtain the so-called squeegee action of rubbing the ink against the inner surface of the cylindrical plate sleeve in order to push it from the inner circumferential surface to the outer circumferential surface of the cylindrical plate cylinder, it is necessary to The circumferential speed of the outer circumferential surface of the supply roller is low, and this causes the inner circumferential surface of the cylindrical plate cylinder to move relative to the outer circumferential surface of the ink supply loaf in a direction that pushes the ink supplied between them toward the inner circumferential surface. It is preferable that the two parts move in a consistent manner and some degree of rubbing occurs between the two parts. Regarding this point, we have conducted various experimental studies and found that the ratio of the accompanying rotation speed of the outer circumferential surface of the ink supply roller to the inner circumferential surface of the cylindrical plate cylinder is approximately 1/5 to 2/5. It has been found that a particularly good print finish can be obtained when

Based on this recognition of the circumferential velocity ratio of the outer circumferential surface of the ink supply roller to the inner circumferential surface of the cylindrical plate cylinder, the present invention provides an improved stencil printing apparatus that can always ensure the best printing finish. This is a proposal.

The invention will now be described in detail by way of example embodiments with reference to the accompanying drawings.

The attached Figures 1 and 2 illustrate the present invention.
8043 is a schematic configuration diagram showing one embodiment incorporated into the stencil printing apparatus proposed in No. 8043.

The illustrated stencil printing device has a cylindrical plate 8 and 1 having a predetermined width.
have. The cylindrical plate 8 has a porous structure that allows printing ink to pass through. It includes a screen layer having a laminate structure of a stainless fiber mesh screen layer 3 disposed on the outer periphery and a reticulated polyester synthetic resin layer 4 disposed to cover the outer periphery. The rotating shaft 30 of the cylindrical plate 8 is rotated by an electric motor 31, such as a motor shaft 32, a pulley 33, a belt 34, It is designed to be rotationally driven via a pulley 35. Further, the cylindrical plate 8 and 1 has a base paper mounting portion 6 on a part of its outer periphery, which locks the mounting margin (base paper top) of the stencil paper 5, and the mounting margin is secured to this base paper mounting portion 6. The stencil paper 5 is held in close contact with the outer peripheral surface of the cylindrical plate cylinder 1 due to the viscosity of the printing ink, and rotates integrally with the cylindrical plate cylinder 1. Inside the cylindrical plate cylinder 1, a printing ink supply roller 7 having a smaller depression is arranged. is a pulley 37, a belt 38,
By being driven via the pulley 39, the cylindrical plate 8 rotates counterclockwise around its own central axis C2 as viewed in FIG. 1 in accordance with the rotation of the cylindrical plate 8.

In the illustrated embodiment, the pulleys 37 and 39 have the same diameter, while the ratio of the inner diameter of the cylindrical plates 8 and 1 to the outer diameter of the printing ink supply roller 7 is approximately 3.6:1. Therefore, the ratio of the circumferential velocities at the contact portion between the two is approximately 3.6:1.
Note that the rotating shafts 30 and 36 are rotatably supported by the support structure 4. Further, within the cylindrical plate 1, a doctor rod 8 is arranged along the loaf generatrix at a predetermined distance 9 from the outer peripheral surface of the printing ink supply roller 7. This doctor rod 8 has both ends supported by the support structure 401, and may or may not be rotatable. Printing ink is supplied from an ink supply pipe 1 to the right side of the doctor rod 8 in FIG. An ink reservoir 11 is formed in a target space defined by the outer peripheral surface of the roller 7 and the outer peripheral surface of the doctor rod 8. Ink supply pipe 01 Printing ink is supplied through an ink supply pipe (not shown).

When the size (ink amount) of the ink reservoir 11 becomes less than a predetermined value, printing ink is ejected, and when the size of the ink reservoir 11 becomes more than a predetermined value, the ejection of printing ink is stopped, Replenishment of printing ink is controlled so as to keep the size of the ink reservoir 11 substantially constant. The size of the ink reservoir 1'1 is detected by an ink amount detection lever 13. The ink amount detection rod 13 is pivotally supported by a pivot shaft 14, and when the size of the ink reservoir 11 is larger than a predetermined value, its tip is caught in the printing ink in the ink reservoir 11. Due to the flow, the ink amount detection block 13 is given a rotational force in the counterclockwise direction as shown in the figure and moves away from the microswitch 15. On the other hand, when the size of the ink reservoir 11 becomes less than a predetermined value, the tip of the ink reservoir 13 is moved away from the microswitch 15. The ink amount detection rod 13 is separated from the printing ink 11 and is rotated clockwise by the bell 1$, and comes into contact with the microswitch 15 to operate it. Micro switch 15
may be configured to control the operation of the ink supply pipe (not shown). A press roller 16 is rotatably provided on the outer periphery of the cylindrical plate cylinder 1 and faces the printing ink supply roller 7 across the cylindrical plate.

This press roller 16 is connected to a lever 1 whose one end is pivoted by a pivot 17 to a fixed member of the device (not shown).
The lever 18 is supported by a pivot 19 on the other end of the press roller 6, and the lever 18 is exerted by a spring force in a counterclockwise direction as viewed in FIG. is operably pressed toward the outer circumferential surface of the The pivot 19 carries a cam follower 21 which engages a cam 22 fixedly attached to one side of the cylindrical plate cylinder 1, so that the press roller 16 When corresponding to the base paper attachment part 6 of the same month, the press roller 6
is pulled away from the cylindrical plate cylinder 1. The printing paper 23 to be printed is stacked on a paper feed tray (not shown in the figure), and is taken out one by one starting from the top one by a paper feed roller (not shown in the figure). is sent to a pair of timing rollers and guide rollers (not shown), and is sent between the stencil paper 5 mounted on the outer peripheral surface of the cylindrical plate cylinder 1 and the press roller 6 at a predetermined time by the timing rollers. The printing ink that has passed through the perforations of the stencil paper 5 is transferred thereto, and after printing is completed, it is discharged onto a paper discharge table (not shown in the figure).

The printing ink in the ink reservoir 11 is supplied to the printing ink supply roller 7
As the printing ink rotates, the printing ink flows clockwise around an axis parallel to the central axis C2 of the printing ink supply roller 7, as shown by the arrow in the figure, and a part of the printing ink flows into the printing ink supply roller 7. When passing through the gap 9 between the printing ink supply roller 7 and the doctor rod 8, the printing ink adheres to the outer peripheral surface of the printing ink supply roller 7 while being metered, and a printing ink layer of uniform thickness is formed on the outer peripheral surface of the printing ink supply roller 7. Form 29. As the printing ink supply roller 7 rotates, this printing ink layer 29 is transferred to the contact area between the printing ink supply roller 7 and the cylindrical plate 1, and in that contact area, the inner peripheral surface of the cylindrical plate 8 is Further, in this part, the circumferential speed of the cylindrical plate cylinder 1 is higher than the circumferential speed of the printing ink supply roller 7, so that the printing ink on the outer circumferential surface of the printing ink supply loaf 7 is transferred to the inner circumference of the cylindrical plate cylinder 4. Pressed by the squeegee action that rubs against the surface,
Passing through the cylindrical plate cylinder 1 from its inner peripheral surface to its outer peripheral surface,
Furthermore, it passes through the perforations of the stencil paper 5 and is transferred to the surface of the printing paper 23. Thus, according to the present invention, the degree to which the outer circumferential surface of the printing ink supply roller 7 rubs against the inner circumferential surface of the cylindrical plates 8 and 1 is always kept constant, and The strength of the squeegee action that rubs ink is always set to a constant level, so that the level of ink supplied to the stencil paper is always constant, and even when printing a large number of prints in succession, it remains constant from start to finish. It is possible to obtain printed matter with a finish of

According to the present invention, the ratio at which the circumferential speed of the outer circumferential surface of the printing ink supply roller 7 is reduced relative to the circumferential speed of the inner circumferential surface of the cylindrical plate cylinder 1 is as follows: In the case of a rotary stencil printing device, 1/3. It has been confirmed that favorable printing results can be obtained at such a ratio. In order to provide such a ratio of peripheral speeds, the diameter of the outer peripheral surface of the printing ink supply roller 7 must be 5.
In this case, the cylindrical plate cylinder and the printing ink supply roller may be rotated at the same rotational speed, so that the axis of rotation of the cylindrical plate cylinder and the printing ink supply roller are the same as in the illustrated embodiment of the present application. It is sufficient to connect the rotating shaft of the supply roller with a 1:0 belt-to-pulley transmission system. As is clear from FIG. 1, arranging the printing ink supply roller 7 whose outer circumferential surface has a diameter of 180 mm inside the cylindrical plate cylinder 1 whose outer circumferential surface has a diameter of 180 mm is the same as that of the cylindrical plate 8. A preferable balance can be obtained in terms of the internal structure of the device. However, such conditions are not absolute for the present invention, and the reduction ratio of the circumferential speed of the outer circumferential surface of the printing ink supply roller to the circumferential speed of the inner circumferential surface of the cylindrical plate cylinder is within a fairly wide range centering on such embodiments. The printing ink supply roller may be modified accordingly, as in the illustrated embodiment, by a transmission system in which the shaft of rotation of the printing ink supply roller is driven from the shaft of rotation of the cylindrical plate cylinder via a belt-pulley system. The reduction ratio may be changed arbitrarily. on the other hand,
The shape of the ink pool 11 formed on the outer peripheral surface of the printing ink supply roller 7 becomes unstable if the rotation speed at which it is rotated around its central axis by the rotation of the printing ink supply roller 7 is too high. And what's more, the ink flies all over the place. From this point of view, the ink reservoir 11 is preferably rotated at a relatively gentle degree. From this point of view, the printing ink supply roller 7
It is preferable that the cylindrical plate cylinder 1 be rotated at the same rotational angular velocity as that of the cylindrical plate cylinder 1, and even when the rotational speed of the cylindrical plate cylinder is increased thereby to achieve a high speed ratio of printing,
It is possible to maintain the rotational speed of the ink reservoir 11 at an appropriate value. Although the present invention has been described in detail with respect to one embodiment above, the present invention is not limited to this embodiment, and various other embodiments are possible within the scope of the present invention. This will be clear to those skilled in the art.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing one embodiment of a stencil printing apparatus according to the present invention, and FIG. 2 is a schematic configuration diagram showing a cross section of the apparatus shown in FIG. . 1-cylindrical plate arm, 2-cylindrical body, 3-stainless steel mesh layer, 4-synthetic fiber layer, 5-stencil paper, 6-base paper attachment part,
7~Printing ink supply roller, 8~Doctor rod, 9~
Gap, 10 - Ink supply pipe, 11 - Ink reservoir, 1
3 ~ Ink amount detection rod, 13a ~ Weight, 14 ~ Pivot, 15 ~
Micro switch, 16~press o-ra, 17~axis,
18 - lever, 20 - spring, 21 - cam follower, 22 - cam, 23 - printing paper, 29 - printing ink layer, 3
0 - cylindrical plate and its rotating shaft, 31 - electric motor, 32 - electric motor hoe, 33 - pulley, 34 - belt, 35 - pulley, 3
6 ~ Rotating shaft of printing ink supply roller, 37 ~ Pulley, 3
8 - belt, 39 - pulley, 40 - support structure. Figure 1 Figure 2

Claims (1)

[Claims] 1 a rotating shaft, and a stencil paper carried by the rotating shaft and extending in the same manner around the rotating shaft, attached to the outer peripheral surface and driven to rotate around its own central axis by the rotating shaft; a porous cylindrical plate cylinder, and a rotating shaft disposed parallel to the central axis of the cylindrical plate cylinder in a space between the rotating shaft and the inner peripheral surface of the cylindrical plate cylinder. an ink supply roller which is arranged so that its outer circumferential surface contacts the inner circumferential surface of the cylindrical plate cylinder and rotates around its own central axis; and an ink layer of a predetermined thickness is applied to the outer circumferential surface of the ink supply roller. an ink applicator that rotates around its own central axis and has an outer circumferential surface disposed opposite to the outer circumferential surface of the cylindrical plate cylinder; and a press roller that rotates around its own central axis; The ink is supplied as the cylindrical plate cylinder rotates, and includes two pulleys each having a similar diameter and attached to a rotating shaft of a supply roller, and an endless belt stretched between the two pulleys. 1. A stencil printing device comprising a driving force transmitting means for rotating a roller.