JPH04101848A - Ink calling roller of offset printing machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an ink feed roller for an offset printing press that has an improved positional relationship with respect to an ink source roller.

(Prior art) In an offset printing press, ink is supplied from an ink fountain to the surface of the plate cylinder via a number of ink rollers, and dampening water is supplied to the surface of the plate cylinder via a dampening water roller. Some of the ink, etc. is transferred from the top of this plate cylinder to the blanket cylinder (
Printing is performed by transferring the paper to be printed while being in pressure contact between the blanket cylinder and an impression cylinder or blanket cylinder (in the case of an offset rotary printing press). When performing multi-color printing, printing units with the above configuration are installed in multiple stages for each color, and the paper to be printed is continuously transferred to these multi-stage printing units, so that each color is sequentially printed. Printing is now possible.

FIG. 2 shows a roller mechanism including an ink roller and a dampening solution in a conventional offset printing press of this type. As disclosed, each printing unit includes an ink fountain L disposed in an upper position and a number of rollers for supplying ink in the ink fountain 1 to a lower plate cylinder 2. It is equipped with a roller group 3. An ink source roller 4 is disposed facing the ink fountain 1, and a large number of blades 5 are arranged at intervals in the width direction at the lower end of the ink fountain 1 at positions facing the ink source roller 4. They are lined up.

These blades 5 can be opened and closed individually, thereby making it possible to adjust the density in the width direction. The ink roller group 3 also includes a transmission roller 6 arranged horizontally and spaced apart from the ink source roller 4, and a transmission roller 6 that reciprocates between the ink source roller 4 and the transmission roller 6. 4 to the transfer roller 6, and a large number of rollers arranged in series between the transfer roller 6 and the plate cylinder 2 to form an ink supply path. This roller group includes three swinging rollers, a first swinging roller 8, a second swinging roller 9, and a third swinging roller 10, on the way, and a second roller 11 that contacts the plate cylinder 2. The third roller 12 includes a roller 12 and a plurality of kneading rollers 13 interposed in the ink path. On the other hand, a water boat 14 is provided at a side position of the plate cylinder 2, and a water head roller is provided between the water boat 14 and the plate cylinder 2. 5. Chrome roller 16. The swimsuit is provided with a dampening water roller group 19 consisting of a roller 17 and a water swinging roller 18, and the dampening water in the water boat 14 is supplied to the plate cylinder 2 via this dampening water roller group 19. . In the figure, 20 indicates the first roller, and 21 indicates the blanket cylinder pressed against the plate cylinder 2.

In the roller mechanism configured as described above, the ink fountain l
The ink inside is supplied from the ink source roller 4 to the surface of the plate cylinder 2 via a large number of ink roller groups 3, and on the other hand,
The dampening water in the water bucket 14 is supplied to the surface of the plate cylinder 2 via a dampening water roller group 19. At this time, the kneading roller 13 and the swimsuit in the ink roller group 3 are transferred to the dampening water roller through the water swinging roller 18 that contacts both the rollers 17. The ink and dampening water are mixed and emulsified and then supplied to the plate cylinder 2.

In printing each color in each printing unit, a portion of the ink supplied to the surface of the plate cylinder 2 is transferred to the blanket cylinder 2I.
After being transferred onto the surface of the Plunket cylinder 21 and an impression cylinder or blanket cylinder (not shown), the image is transferred onto a sheet of paper that passes between the Plunket cylinder 21 and an impression cylinder or blanket cylinder (not shown). At this time, the amount of ink supplied to the surface of the plate cylinder 2 is adjusted by adjusting the amount of rotation of the ink source roller 4 arranged adjacent to the ink amount l, and by setting a width apart from the ink source roller 4, respectively. This is done by adjusting the opening degree of a large number of blades 5 arranged in the direction.

(Problem to be solved by the invention) By the way, in the above-mentioned offset printing machine,
The ink source roller 4 is rotated at a slow speed of, for example, one rotation every 20 to 40 seconds, and an ink film is formed on the surface of the roller 4 as it rotates. Then, the ink film thus formed is sequentially transferred to the transmission roller 6 which rotates at high speed by the oscillating pick-up roller 7.

However, when the ink source roller 4 and the feed roller 7 are arranged horizontally as shown in FIG. 2, the ink film thickness can be adjusted by adjusting the opening of the blade 5. When changing the ink amount, it takes several seconds or more for the change in the ink amount to reach the feed roller 7, and as a result, the transmission of the change in the amount of ink to the surface of the plate cylinder 2 is delayed, and a considerable number of sheets of paper are lost during that time. There was an inconvenience that a loss occurred.

The present invention has been made in view of the above-mentioned problems, and is capable of quickly transmitting changes in the ink film thickness of the ink source roller to the plate surface, thereby significantly reducing the number of sheets with poor color tone at the time of printing. The purpose is to obtain an ink feed roller for an offset printing machine that can be used in an offset printing press.

(Means for Solving the Problems) An ink calling roller for an offset printing press according to the present invention is an ink calling roller for an offset printing press that transfers ink from an ink source roller to a transmission roller. The contact position with the ink source roller is located below the ink source roller and within a range of 60° left and right with respect to a perpendicular line passing through the center of the ink source roller.

(Function) In the present invention, the contact position between the ink feed roller and the ink source roller is within a range of 60 degrees left and right with respect to a perpendicular line passing through the center of the ink source roller, and is extremely close to the ink fountain. Therefore, changes in the ink film thickness on the ink source roller can be quickly transmitted to the transmission roller.
As a result, the number of sheets with poor color tone during printing can be significantly reduced.

(Example) Examples will be described below based on the drawings.

FIG. 1 is a structural diagram of a roller mechanism of an offset printing press according to an embodiment of the present invention.

In this embodiment, the ink fountain 11 plate cylinder 2. The configuration of the device consisting of the water boat 14 and the like is basically the same as the conventional device shown in FIG. Therefore, the configurations and functions common to those of the apparatus shown in FIG. 2 are designated by the same reference numerals in the figure, and the description thereof will be omitted, and the following description will focus on the points unique to this embodiment.

In this embodiment, the transmission roller 6 is disposed inside the apparatus (on the side located approximately directly above the plate cylinder 2) compared to the conventional one, and this transmission roller 6
A feed roller 7 and an ink source roller 4 are arranged so as to be located directly above the ink roller.

In this way, the contact position of the feed roller 7 with the ink source roller 4 is on a perpendicular line passing through the center of the ink source roller 4, and the distance between the contact position and the blade 5 of the ink fountain 1 is close. Become.

Thereby, when the ink film thickness is changed by adjusting the opening degree of the blade 5, the time required for the change in film thickness to reach the calling roller 7 can be significantly shortened.
Therefore, it is possible to significantly reduce the number of printed sheets with defective color tone.

In the above embodiment, the positional relationship between the feed roller 7 and the ink source roller 4 is set such that the contact position of both rollers is exactly on a perpendicular line passing through the center of the ink source roller 4. As described above, the closer the contact position is to the plate 5, the more quickly changes in the ink film thickness can be transmitted to the transmission roller 6. Also,
If this contact position is set within a range of 60 degrees to the left and right of a perpendicular line passing through the center of the ink source roller 4, the desired effect will be achieved.

(Effects of the Invention) Since the present invention is configured as described above, changes in the ink film thickness of the ink source roller can be quickly transmitted to the plate surface, thereby significantly reducing the number of sheets with poor color tone at the time of printing. can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a structural diagram of a roller mechanism of an offset printing press according to an embodiment of the present invention, and FIG. 2 is a conventional structural diagram of the same. 4: Ink source roller - 6 transmission roller 7 calling roller

Claims (1)

[Claims] (1) In an ink feed roller of an offset printing machine that transfers ink from an ink source roller to a transmission roller, the contact position between the ink feed roller and the ink source roller is below the ink source roller. An ink feed roller for an offset printing press, characterized in that the ink feed roller is within a range of 60 degrees left and right with respect to a perpendicular line passing through the center of the ink feed roller.