JPH04113879A - Stencil printing device - Google Patents

Abstract

PURPOSE:To maintain the pressing force of a press roller at an optimal level required for ink transfer by adjusting print density under the control of an ink roller and a press roller due to the movement of a roller support. CONSTITUTION:The amount of ink 14 transferred increases in proportion to the increase in perforation density of a sheet and the decrease in rotary speed of a multi-perforation stencil plate cylinder 1 or the increase in fluidity of ink 14 at high temperature. In this case, an eccentric shaft 18 is rotated at a specified angle by a stepping motor 19. Consequently, a roller support 4 rotates centered around a fulcrum 3, resulting in the movement of an ink roller 5 in the transport direction of a sheet 16. The larger amount of a movement l, the less lap value of the ink roller 5 and a press roller 11. Thus the amount of the transferred ink 14 becomes less. That is, the print becomes less thick. However, the pressing force of the press roller 1 can be maintained at an optimal level required for ink transfer, so that the print becomes clear at an optimal print density.

Description

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

Conventionally, a rotatable ink roller is brought into contact with the inner surface of a rotatably held cylindrical perforated plate cylinder, ink is supplied to the outer circumference of the ink roller, and perforations are made by a method such as an electric discharge method or a heat-sensitive method. The process of wrapping the prepared base paper around the outer periphery of the perforated plate cylinder, pressing the paper against the outer periphery of the perforated plate cylinder with a press roller, rotating the perforated plate cylinder and the ink roller, causing the press roller to follow the rotation and conveying the paper. in,
In a stencil printing device that transfers ink to paper through a perforation cylinder and a base paper, the printing density changes depending on factors such as the perforation density of the base paper, the rotational speed of the perforation cylinder, and changes in ink fluidity due to temperature changes. .

For this reason, as described in Japanese Utility Model Application Publication No. 54-174407, there is an idea to adjust the printing density by changing the amount of ink transferred by adjusting the pressing force of a press roller against the paper.

Problems to be Solved by the Invention The invention described in Japanese Utility Model Application Publication No. 54-174407 is as follows:
For example, if the fluidity of the ink is high, the pressing force of the press roller must be adjusted to below a certain pressure. There is a problem that a white spot phenomenon occurs in a part of the area where ink should be transferred (solid area).

Means for Solving the Problems The invention of claim 1 provides a rotatably held cylindrical perforated cylinder, an ink roller that contacts the inner surface of the perforated cylinder, and an ink roller that applies ink to the outer peripheral surface of the ink roller. an ink supplying means; a rotatable press roller disposed opposite to the perforation cylinder with a sheet conveyed in a tangential direction of the perforation cylinder; and the press roller attached to the perforation cylinder. and a roller support that rotatably holds either the ink roller or the press roller and is movably held along the conveying direction of the paper.

According to a second aspect of the invention, the amount of movement of the roller support is set based on detection signals from a speed detection means for detecting the rotational speed of the perforation cylinder and a temperature detection means for detecting the temperature around the perforation cylinder. A movement amount setting means is provided.

Effect of the invention of claim 1 is that the amount of overlap between the ink roller and the press roller can be adjusted by the movement of the roller support, thereby adjusting the printing density. Therefore, it is possible to maintain the pressure at an optimum level, thereby achieving a clear printing condition with an optimum printing density.

The invention according to claim 2 further provides a clear printing state by detecting the rotational speed of the stencil cylinder and the temperature that affects the fluidity of the ink and adjusting the amount of overlap between the ink roller and the press roller. It becomes possible to obtain.

Example An embodiment of the present invention will be described based on the drawings.

As shown in FIGS. 1 and 2, a cylindrical perforated plate cylinder 1 having a screen mesh on its outer periphery is provided. As shown in FIG. 3, the center of a flange 2 fixed to both side edges of the perforated plate cylinder 1 is rotatably supported by a support shaft 3. As shown in FIG. A shaft 6 of an ink roller 5 that contacts the inner surface of the perforated plate cylinder 1 is rotatably supported on a pair of roller supports 4 that are swingably held on the support shaft 3 at a predetermined interval. At the same time, a doctor roller 7 is held opposite the outer peripheral surface of the ink roller 5 with a slight gap therebetween.

Further, a gear 8 is integrally formed at the center of the inner surface of the flange 2, a gear 9 is fixed to the end of the shaft 6 of the ink roller 5, and an idle gear 10 meshed with these gears 8°9 is connected. It is rotatably held by one roller support 4. Further, as shown in FIGS. 1 and 2, a press roller 11, which is disposed opposite to the outer periphery of the perforated plate cylinder l, is rotatably supported on the tip of a lever 13 that rotates around a support shaft 12. There is. This lever 13 has a function as a pressing means that is biased by a biasing member (not shown) to press the press roller 11 toward the perforated plate cylinder 1 side. Further, an ink supply means (pipe) 15 for supplying ink 14 is provided on the upper outer periphery of the ink roller 5. Further, both ends of an eccentric shaft 18 are rotatably supported by arms 17 fixed to both ends of the support shaft 3.
A step motor 19 connected to one end of the arm 8 is fixed to one arm 17. Furthermore, a notch 20 is formed in the roller support body 4 and is fitted into the eccentric shaft 18 .

In such a configuration, a base paper (
(not shown) is wound. Then, the paper 16 is inserted between the perforated plate cylinder 1 and the press roller 11, and
In the figure, in the process of driving the perforation cylinder 1 clockwise and conveying the paper 16 to the left, printing is performed by transferring the ink 14 supplied to the ink roller 5 to the paper 16 through the perforation cylinder 1 and the base paper. It will be done. At this time, ink roller 5
The perforated plate cylinder 1 rotates in the same direction, and the press roller 11 follows and rotates counterclockwise. FIG. 1 shows the ink roller 5 and the press roller 1 in a state where the center of the ink roller 5 is located on a straight line passing through the centers of the support shaft 3 and the press roller 11.
In the state where the amount of overlap with 1 is the largest, the amount of transferred ink 14 is also proportionally large.

As the perforation density of the base paper is high and the rotational speed of the perforated plate cylinder l is slow, or the temperature is high and the fluidity of the ink 14 increases, the amount of ink 14 transferred increases. By rotating the eccentric shaft 18 by a predetermined angle, the roller support body 4 rotates around the support shaft 3, as shown in FIG.
6 in the transport direction. As shown in FIG. 4, the larger the moving amount Q, the smaller the amount of overlap between the ink roller 5 and the press roller 11, and the smaller the amount of ink 14 transferred. That is, the print density becomes lighter. However, since the pressurizing force of the press roller 11 can be maintained at the optimal pressure necessary for ink transfer, it is possible to obtain a clear printing state with optimal printing density.

Although not shown, a speed detection means such as an encoder for detecting the rotational speed of the perforated plate cylinder l is provided.
By providing a temperature detecting means for detecting the ambient temperature of the roller support 4 and a moving amount setting means for setting the moving amount of the roller support 4 based on the detection signals of these speed detecting means and the temperature detecting means, By detecting the rotational speed of the plate cylinder 1 and the temperature that affects the fluidity of the ink 14 and adjusting the amount of overlap between the ink roller 5 and the press roller 11, it is possible to obtain a clearer printing state. becomes.

In the above embodiment, the ink roller 5 is moved relative to the press roller 11 by swinging the roller support 4, but the lever 13 is moved together with the support shaft 12 to press the ink roller 5. The same objective can be achieved by moving the rollers 11.

Effects of the Invention As described above, the invention of claim 1 includes a rotatably held cylindrical perforated cylinder, an ink roller that contacts the inner surface of the perforated cylinder, and an ink roller that applies ink to the outer peripheral surface of the ink roller. an ink supplying means; a rotatable press roller disposed opposite to the perforation cylinder with a sheet conveyed in a tangential direction of the perforation cylinder; and the press roller attached to the perforation cylinder. and a roller support that rotatably holds either the ink roller or the press roller and is movably held along the conveying direction of the paper. The printing density can be adjusted by adjusting the amount of overlap between the ink roller and the press roller by moving the support, thereby maintaining the pressing force of the press roller at the optimal pressure required for ink transfer. Therefore, it is possible to obtain a clear printing condition with optimum printing density.

According to a second aspect of the invention, the amount of movement of the roller support is set based on detection signals from a speed detection means for detecting the rotational speed of the perforation cylinder and a temperature detection means for detecting the temperature around the perforation cylinder. Since a movement amount setting means is provided, the rotational speed of the perforated plate cylinder and the temperature that affects the fluidity of the ink can be detected and the amount of overlap between the ink roller and press roller can be adjusted, resulting in even clearer printing. It has the effect of allowing you to obtain the status.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIGS.
The figure is a front view, FIG. 3 is a vertical side view, and FIG. 4 is a graph showing the relationship between the ink roller movement amount and printing density.

Claims (1)

[Scope of Claims] 1. A cylindrical perforated plate cylinder that is rotatably held, an ink roller that contacts the inner surface of the perforated plate cylinder, and an ink supply means that supplies ink to the outer peripheral surface of the ink roller. , a rotatable press roller disposed opposite to the perforation cylinder with a sheet conveyed in a tangential direction of the perforation cylinder;
a pressure means for urging the press roller toward the perforated plate cylinder; and a pressure means for rotatably holding either the ink roller or the press roller and movably along the conveying direction of the paper. A stencil printing device comprising: a roller support body; 2. Movement amount setting means for setting the movement amount of the roller support based on detection signals from a speed detection means for detecting the rotational speed of the perforation plate cylinder and a temperature detection means for detecting the temperature around the perforation cylinder. The stencil printing apparatus according to claim 1, further comprising: a stencil printing apparatus.