JP2007112012A - Printing device and elastic material-covered roller thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a nip pressure near a shaft end from changing with regard to an elastic material-covered roller mounted on the printing device and the printing device. <P>SOLUTION: The elastic material-covered roller of the printing device is constituted of a thin-wall portion of a roller end part, a thick-walled portion of a roller center part and a changing portion between the former two formed on the inner surface side of the elastic material so that a smooth change from the thin-wall portion to the thick-wall portion or vice versa can be realized. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a printing apparatus and an elastic material coating roller of the printing apparatus.

  A conventional apparatus will be described with reference to FIGS. 4 and 6 are sectional views of the roller end, FIGS. 5 and 7 are graphs of the nip pressure at the roller end, FIG. 8 is a sectional view of the printing device, and FIG. 9 is a sectional view of the dampening device.

As shown in FIG. 8, the printing apparatus 1 in the offset rotary press is supplied with dampening water from a dampening device 5 to a plate cylinder 2 on which a printing plate on which a pattern has been baked is mounted. The ink is supplied from the ink, and the ink is attached to the pattern portion of the printing plate. After the ink is transferred to the blanket cylinder 3, it is transferred to the web for printing. The inking device 4 and the dampening device 5 use a large number of elastic material (generally synthetic rubber) coated rollers. In the dampening device 5, the water source roller 10 that pumps up the dampening water 7 supplied to the water boat 6 is also an elastic material coating roller, and the dampening water 7 is pumped up by the water source roller 10, and the water is the water of the other roller The kneading roller 9 (metal roller) is kneaded so as to form a uniform water film in the width direction, and is supplied from the swim roller 8 to the printing plate mounted on the plate cylinder 2.

The supply amount of the fountain solution 7 is roughly determined by the rotational speed of the water source roller 10 and the nip pressure between the water source roller 10 and the water kneading roller 9, and the width direction is uniformly supplied as described above. The supply of dampening water may be changed in the width direction by intentionally changing the nip pressure. However, if there is an unintended nip pressure change, a failure occurs. When the nip pressure is lowered, the water supply becomes excessive, which inhibits the transfer of ink, causes stains due to water scattering, and causes rust on the machine. As shown in FIG. 5, the general conventional water source roller 10 ′ shown in FIG. 4 has a tendency to decrease the nip pressure on the roller end surface, and as described above, excessive supply of dampening water occurs at the roller end. To do. This phenomenon is considered because the end 102a of the elastic member 102 of the water source roller 10 'escapes in the axial direction and the outer diameter becomes small.

Therefore, in order to prevent the above-described decrease in the nip pressure on the roller end surface, it is shown in FIGS.
Has been proposed. However, this type of water source roller 10 'can prevent the end face 102' of the elastic material 102 from escaping in the axial direction, and can easily maintain the nip pressure uniformly, so that the outer diameter of the water source roller does not change. I have to.

JP 2002-172750 A

However, in the roller in Patent Document 1 described above, when the iron core 101 is covered with rubber (elastic material), air easily enters the corner portion 102b of the elastic material 102, and the mixed air particles expand due to temperature changes during operation.・ Shrinks to make it easier for the water source roller to change its outer diameter. This has revealed a problem that the dampening water supply becomes unstable and adversely affects the print quality. As a result of confirmation of the actual machine status, problems with print quality frequently occur when the corner R of the 102b is 1.0 mmR, and even if R is increased, the frequency is reduced but not completely solved.

In order to solve the above-mentioned problem, the present invention according to claim 1 is the printing apparatus of the printing machine, wherein the coating thickness of the elastic material of the elastic material coating roller is such that the thin end portion of the roller end portion and the central portion of the roller It is characterized by comprising an elastic material covering roller composed of a thick portion and a changing portion which is provided with a level difference between the different thickness portions on the inner surface side of the elastic material so as to change smoothly.
Further, in the elastic material coating roller of the printing apparatus, the elastic material coating has a thickness difference between the thin portion at the end of the roller, the thick portion at the central portion of the roller, and the portion having a different thickness. It is characterized by comprising a change part which is provided in and smoothly changes.

  According to the elastic material covering roller of the printing press according to the present invention, the elastic material end portion 102a is less likely to escape in the axial direction, and bubbles are mixed into the elastic material due to the absence of the extreme corner portion 102b in the elastic material coating process. And the diameter is stable even during operation. Therefore, there is an effect that uniform dampening water can be always supplied. In addition, the surface of the iron core 101 of the elastic material coating roller is roughened by shot blasting or the like so that the elastic material can be easily attached before the coating processing. is there.

(Embodiment)
As an example of the elastic material covering roller according to the embodiment of the present invention, a case of a water source roller will be described with reference to FIGS. 1 to 3 and FIG. 9. In addition, about the site | part same as the above-mentioned conventional thing, the same code | symbol is attached | subjected and shown in a figure, and the overlapping description is abbreviate | omitted as much as possible.
As described above, the water source roller 10 immersed in the water boat 6 holding the dampening water 7 at a certain level is rotated by a driving device (not shown) to lift the dampening water 7 on the roller surface. A water film that is appropriate and uniform in the width direction is supplied by the nip pressure with the water kneading roller 9.

As shown in FIG. 1, the water source roller 10 of the present invention covers the core 101 with rubber (elastic material), but the roller main body portion includes a portion where the core core 101d has a large rubber thickness and an iron core. The large-diameter portion of the end portion 101b includes a thin rubber portion, and the iron core central portion 101d and an inclined portion 101c that smoothly changes the core end portion 101b.
With this configuration, when the shape is determined in consideration of the elastic modulus and the rubber thickness of the rubber, the amount of relief in the axial direction of the rubber end portion 102a is reduced, and as shown in FIG. 3, the nip pressure is almost uniform up to the roller end portion. Can be obtained.

  The shape of the inclined portion 101c that smoothly changes the iron core central portion 101d and the iron core end portion 101b of the water source roller 10 of the present invention can be variously formed as shown in FIG. In addition to eliminating the retention of bubbles without having a radial surface perpendicular to the core, it is determined in consideration of the ease of manufacturing during the process.

  Further, in the rubber coating process, the sheet-like rubber material is wound around the iron core 101 and then formed by applying pressure from the outside. Therefore, if there is an extreme corner portion 102b as in the prior art, bubbles are likely to be mixed into the rubber. Since the inclined portion 101c is provided, the bubbles are hardly mixed into the rubber, and it is possible to prevent the nip pressure from being changed due to the diameter change due to the expansion and contraction of the bubbles due to the temperature change of the roller. . Therefore, there is an effect that a stable water film can be supplied even in continuous operation.

  Further, when an elastic material covering roller such as the water source roller 10 is used for a certain period, it is necessary to rewind the covering elastic material 102. In the rewinding, after the elastic material 102 is scraped off, shot blasting for roughening the surface is performed in order to make the new elastic material 102 easily adhere to the surface of the iron core 101. At this time, there is no corner portion 102b having a radial surface on the surface of the iron core 101 that is difficult to hit the blasting particles flying in the radial direction, and shot blasting can be performed easily and uniformly, and the workability of processing is good. Thus, the finished product is homogeneous and high quality is obtained, the adhesion of the elastic material 102 is stabilized, and the probability of occurrence of troubles such as peeling is reduced.

1 is a partial cross-sectional view of a water source roller (elastic material-covered roller) according to an embodiment of the present invention, and FIG. 1A is a view showing various forms of the iron core inclined portion 101c portion of FIG. It is sectional drawing of the principal part contact state in the water source roller driving | running which concerns on embodiment of this invention. It is a nip pressure state graph of the water source roller end part concerning an embodiment of the invention. It is sectional drawing of the principal part contact state in the conventional general water source roller driving | operation. It is a nip pressure state graph of the conventional common water-source roller edge part. It is sectional drawing of the principal part contact state during the conventional improved water source roller driving | operation. It is a nip pressure state graph of the conventional improved water source roller end. It is a printing apparatus cross-sectional explanatory drawing of a general offset printing machine. It is a dampening device section explanatory view of a general offset printing press printer.

Explanation of symbols

1 Printing device 1a Upper unit 1b Lower unit 2 Plate cylinder
3 Blanket cylinder 4 Inking device 5 Dampening device 6 Damp boat 7 Dampening water 8 Water roller 9 Water kneading roller 10 Water source roller 101 Iron core 101a Flange 101b Iron core end 101c Iron core inclined portion 101d Iron core central portion 102 Rubber (elastic material) 102a Elastic material end portion 102b Corner portion 11 Inking roller

Claims (2)

  The coating thickness of the elastic material of the elastic material coating roller changes smoothly by providing a step between the thin portion at the end of the roller, the thick portion at the central portion of the roller, and the portion having the different thickness on the inner surface side of the elastic material. A printing apparatus comprising: an elastic material covering roller configured with a changed portion as described above.   In the elastic material coating roller of the printing apparatus, the coating thickness of the elastic material is provided on the inner surface side of the elastic material with a step difference between the thin portion at the end of the roller, the thick portion at the central portion of the roller, and the portion having the above thickness difference. An elastic material covering roller for a printing apparatus, characterized in that the elastic material covering roller is configured with a changing portion that smoothly changes.

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