JPH09290502A - Ink supply quantity control device of rotary press - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form an ink supply quantity control device of a rotary press capable of being effectively adaptable to four colored newspaper printing by providing a member or the like to displaceably support a scraper blade in a contact position and noncontact position of its tip end to the surface of a control roller. SOLUTION: The scraper blade 14 is formed into a serrated blade with a width of about 100mm, a tip end of 25mm in its pitch to be in contact with the surface of a control roller, and an angle of 40 deg.. The scraper 14 in this kind operates to scrape a required quantity of ink from the surface of a rotating control roller 13 and change the ink supply quantity to the press surface so as to control the printing density. If the scraper blade 14 is in a state (dotted line) being not contact with the surface of a control roller 13, the control roller 13 receives ink stayed in the recesses of metering roller 7, and returns ink to the recesses and projections of the roller 7 with the same quantity of ink received.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink supply amount adjusting device for a rotary press equipped with a metering roller type keyless inking system.

[0002]

2. Description of the Related Art A keyless offset newspaper press (keyless press) was initially used for monochrome (black and white) printing, and mainly operates for printing characters, lines, photographs (including advertisements), etc. Was there. Since this keyless machine has a configuration in which the ink adjustment key is removed from the inking system, the adjustment of rollers and the like, the change in ink properties due to temperature changes, and the manufacturing error of the machine, which is presumed to be caused by the machine manufacturing error, etc. Uniformity or variation cannot be corrected in the same way as before. The print density is related to the amount of ink supplied from the inking roller to the plate surface, but the print density in offset printing depends on the amount of ink on the plate surface and the amount of dampening water for that ink amount. Has been done. The density adjustment for printing density defects or correction in the keyless machine is sufficient for newspaper printing by adjusting the amount of dampening water supplied to the plate surface within the range where the waterless ink does not interfere with the keyless inking system itself. Printing is being performed with the density value and density uniformity.

However, in the recent four-color color printing for newspaper printing, the color printing is performed by superposing halftone dots by four kinds of color inks of cyan (C), magenta (M), yellow (Y) and black (BK). The desired color tone of the design is brought out by color-developing by printing. The balance of the print densities of the respective color inks is important, and it is further necessary to secure a reference density for obtaining the color tone of the design. Four
In color printing, which is overprinting of color inks, it is not desirable to adjust the print density of each color ink by the amount of dampening water supplied. Especially when color printing is performed by supplying excessive dampening water, increase in dot gain, change in ink trapping, lack of density, decrease in gloss, etc. occur, and it is difficult to obtain the balance of color tone of the design. Moisture supply to the same pattern four times may be absorbed by the paper to deteriorate the paper and affect the print registration. Therefore, when it is necessary to adjust the color print density, it is desirable to change the print density depending on the amount of ink supply.

[0004]

By the way, the metering roller system which has been developed as an example of the keyless inking system up to now is shown in FIG.
The ink pan 5 that stores the ink, the ink fan ten roller 6 that rotates at a constant speed by driving a single motor (not shown) while being immersed in the ink 4 in the ink pan 5, and the ink that adheres to the surface of the fan ten roller 6. It is installed with a certain gap with the fan-ten roller in order to receive the oil, the roller surface is processed to have irregularities (cell processing), and the surface is subjected to lipophilic and hydrophobic treatment, and it is mechanically driven from the printing machine. The metering roller 7 that is in contact with the convex portion (cell land portion) on the surface of the metering roller 7 that has received the ink 4 scrapes off the ink on the outer periphery of the metering roller, and the ink is stored only in the concave portion. The doctor blade 8 for measuring the amount and the ink for receiving the measured ink accumulated in the concave portion of the surface of the metering roller 7 from the metering roller. A key passing roller 11, ink distribution roller 9 which connects to the ink over the roller 11 constituting the ink roller train, the ink drum 10, the inking roller 12,
Ink is supplied to the plate surface by 12 ', and printing is performed in cooperation with the dampening water device W. 1 is running paper, 2 and 2 are blanket cylinders, and 3 and 3 are plate cylinders.

In such an inking system of the metering roller system, the printing density is determined by the number of recesses and recesses formed on the surface of the metering roller 7 and the multiplier of the volume of the recesses. The amount of ink to be supplied to the ink roller train on the doctor blade 8
Is quantified and quantified to confirm. That is, since the metering roller 7 supplies the ink amount uniformly measured in the paper width direction to the ink roller train, the ink supply including the non-image area on the plate surface is also transferred to the paper and is consumed during printing. Supply is too large, supply and consumption are not balanced. Therefore, excess ink is generated during printing,
This surplus ink is returned to the metering roller 7 along the ink return course, and the inside of the ink roller train is constantly
Since it circulates in a fixed amount, it is not possible to change or adjust the ink supply amount to the ink roller train (density adjustment), and it is not effective to carry out four-color color newspaper printing.

In view of the above, the present invention solves the above-mentioned conventional problems and has a function of arbitrarily adjusting the print density of each color ink,
That is, the present invention provides an ink supply amount adjusting device for a rotary press, which can arbitrarily adjust the amount of ink supplied from the ink supply unit to the inking roller via the ink roller train, and can be effectively adapted to four-color color newspaper printing. The purpose is to

[0007]

In order to achieve the above object, the invention of claim 1 is a rotary press equipped with a metering roller type keyless inking system, and supplies ink from an ink supply section to an ink forming roller. A control roller, which rotates in contact with the surface of an ink roller in the course of the course in a nip state, and a tip portion is provided in contact with almost the entire width of the surface of the control roller, and a part of the ink film on the roller surface is scratched. It is characterized in that it comprises a scraper blade to be taken and a support member which displaceably supports the scraper blade between a position where its tip portion contacts the surface of the control roller and a position where it does not contact the surface of the control roller. According to a second aspect of the present invention, in the first aspect, the ink roller is a metering roller. According to a third aspect of the present invention, in the first or second aspect,
When the support member is in a position where the scraper blade is in contact with the surface of the control roller, the degree of contact of the tip portion of the support member can be adjusted. The invention of claim 4 is claim 1
In any one of 3 to 3, the scraper blade is
It is formed of one elastic thin plate, and the tip end portion which comes into contact with the surface of the control roller is formed as a sawtooth blade having a predetermined pitch.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a blanket cylinder (B) for newspaper printing-blanket cylinder (B) equipped with a metering roller type keyless inking system, and the ink supply amount adjusting device of the present invention is installed in an offset rotary press. It is a front view of one embodiment. In FIG. 1, the same parts as those of the conventional device shown in FIG. 7 are designated by the same reference numerals, and detailed description thereof will be omitted. This offset rotary press is running paper 1
Is a normal type BB offset rotary press that performs simultaneous one-color printing on both sides with a printing cylinder composed of blanket cylinders 2 and 2 and plate cylinders 3 while sheet is passed from the bottom to the top as shown by the arrow. is there.

Reference numeral 13 denotes a control roller, which is adapted to come into contact with the surface of a metering roller 7 as an ink roller in the middle of the ink supply course in a nip state and rotate.
Reference numeral 14 denotes a scraper blade, which is provided with its tip portion in contact with almost the entire width of the surface of the control roller 13 as shown in detail in FIGS. 2, 3 and 4 so as to scrape off a part of the ink film on the roller surface. Has become. The scraper blade 14 is formed of an elastic thin plate made of one hard steel plate (for example, Swedish steel) having a thickness of 0.10 mm, for example. The width of the scraper blade 14 is about 100 mm, and the tip end that comes into contact with the surface of the control roller 13 has a pitch P of 25 mm and is formed into a sawtooth blade with an angle θ of 40 °, and the degree of contact with the surface of the control roller 13 is large. The structure is adjustable.

The scraper blade 14 is fixed to a holder 16 with bolts 15, and the holder 16 is fixed to a through shaft 17 with a key. The scraper blade 14 on one side of the through shaft 17
A lever 18, an adjusting screw shaft 19, and fulcrums 20, 20 'are provided for adjusting the degree of contact between the tip of the control roller and the surface of the control roller 13. The fulcrum 20 'is attached to one side wall of the machine frame, and the adjusting screw shaft 19, the lever 18, the holder 16 and the like including the fulcrum do not contact the position where the tip end of the scraper blade 14 contacts the surface of the control roller 13. A support member (22) that supports the position and is displaceable is configured. When the tip of the scraper blade 14 is in contact with the surface of the control roller 13,
When the adjusting screw shaft 19 is rotated by a wrench or the like not shown, the lever 18 rotates upward with the through shaft 17 as a fulcrum, while the scraper blade 14 rotates downward with the through shaft 17 as a fulcrum. Due to this, the contact degree of the scraper blade 14 changes, the deflection of the saw-toothed tip changes, and the tip of the scraper blade 14 contacts the surface of the control roller 13,
The width of the ink scraped off from the roller changes.

When the tip of the scraper blade 14 is set to have a light contact, the ink film having the width A shown in FIG. 4 is scraped off from the surface of the control roller 13, and when the contact is set to be strong, the saw-toothed tip is bent. Compared with the case of light contact, the ink film of width B (B> A) of 4 is scraped off (BA).
It is possible to reduce the concentration corresponding to the amount. Thus, in this embodiment, the tip shape of the scraper blade 14 whose tip shape is a sawtooth blade is changed to change the degree of contact with the surface of the control roller 13 to adjust the amount of ink scraped from the roller surface. Control print density.

As described above, the scraper blade 14 provided on the control roller 13 so that the degree of contact can be adjusted scrapes off a required amount of ink from the surface of the rotating control roller 13 to supply the ink to the plate surface. To adjust the print density. If the scraper blade 14 is not in contact with the surface of the control roller 13 (OFF state) as shown by the chain line in FIG. 1, the control roller 13 is the ink accumulated in the concave portion of the metering roller 7. Of the metering roller 7 is operated again to return the same amount of ink to the concave and convex portions of the metering roller 7, and a certain amount of ink film is formed on the surface of the control roller 13. There is no change in supply. However, if the scraper blade 14 is in contact with the surface of the control roller 13 (in the ON state) as shown by the solid line in FIG. 1, a part of the ink film on the roller is scraped off and recirculates to the ink pan 5. . The arrow 15 in FIG. 1 indicates the ink scraped by the scraper blade 14 from the surface of the control roller 13. Therefore, the amount of ink transferred from the metering roller 7 to the ink transfer roller 11 is quantified by the concave portion of the metering roller 7 and the doctor blade 8, and the scraper blade 14 scrapes the surface of the control roller 13 more than the measured amount of ink. The amount of ink supplied to the ink pan 5 is reduced by the amount of ink indicated by the arrow, and as a result, the amount of ink transferred to the plate surface by the ink forming rollers 12 and 12 'is reduced and the printing density is lowered.

In the following, the case where the scraper blade 14 does not scrape the ink indicated by the arrow 15 from the surface of the control roller 13 (when it is off) and when it scrapes it (when it is on)
The change in the print density is quantitatively explained from the ink supply amount and the ink return amount. In keyless offset printing, the ink supply unit sends out a uniform amount of viscous paste-like ink in the width direction regardless of the image ratio on the plate surface, and this ink is divided and conveyed at the roller nip part of the ink roller train ( Transfer) go. The ratio of division and conveyance depends on the size of the roller, the material of the roller, and the water content of the ink in the return course, but as a typical example, it is assumed that the division and conveyance are 50% / 50%. To do. Inking roller 12,
Even when the ink is transferred from 12 'to the plate surface, it is divided and transported 50 /
If it is performed at 50, half of the ink supplied from the ink forming rollers 12 and 12 '(image area) or more (non-image area) of the ink amount is returned to the return path of the ink roller train (dotted line in FIG. 1). Along the path) to return to the ink supply section. Since the ink supply device supplies a fixed amount of ink, the smaller the image ratio, the larger the amount of ink returned.
If an image of a certain size on the plate is printed on the paper at the required printing density, and that density requires an ink film thickness of 1 (or an ink amount of 1) on the paper, the ink roller train The ink is transferred by the division and conveyance of the ink film thickness shown in FIGS.

FIG. 5 shows the division and conveyance of the ink film when the scraper blade 14 is not in contact with the surface of the control roller 13 and is off. The ink supply device must supply 6 ink film thicknesses in order to apply 1 ink film thickness to the running paper and print at the required density.

FIG. 6 shows the division and conveyance of the ink film when the scraper blade 14 is in contact with the surface of the control roller 13 and is on and the ink film thickness of 1 is scraped off. In order to apply the ink film thickness of 1 to the running paper and print at the required density, the ink supply device is 7
Ink film thickness must be supplied. The ink supply device calculated a numerical value of 6 for 1 in the case of FIG. 5 and a value of 7 for 1 in the case of FIG. 6, but since the keyless ink supply device supplies a fixed amount of ink, both are actually 6
It is. Even when the scraper blade 14 is in contact with the surface of the control roller 13, the film thickness of the ink supply device is 6, so the ink film thickness reaching the running paper 1 is (1 × 6/7 = 0.86) 0.86. Decrease. If the scraper blade 14 scrapes an ink film thickness of 1,
It is 0.86, and when 2 or 3 is scraped off, the film thickness on the running paper becomes the following value. 0 ... 1x6 / 6 = 1 1 ... 1x6 / 7 = 0.86 2 ... 1x6 / 8 = 0.75 3 ... 1x6 / 9 = 0.66 Thus, it is understood that when a part of the ink supply amount is removed from the ink roller train, the amount of ink reaching the running paper is reduced and the print density is reduced.

Although the control roller 13 is provided in contact with the surface of the metering roller 7 in this embodiment, it may be provided in contact with the surface of the ink kneading roller 9 as well. The metering roller 7 is not always required as long as the ink roller is in the middle of the ink supply course up to. Further, the width of the scraper blade 14 is set to be almost the entire width of the surface of the control roller 13 so that the density of the entire paper width can be adjusted. For example, the scraper blade 14 is divided into four, and each of them individually contacts the surface of the control roller 13. The degree of may be changed.

[0017]

Since the present invention is constructed as described above, it is possible to arbitrarily adjust the amount of ink supplied from the ink supply section to the ink forming roller via the ink roller train, thereby adjusting the print density. To achieve 4
It has an excellent effect that it can be effectively applied to color printing color newspaper printing.

[Brief description of drawings]

FIG. 1 is a front view of an embodiment in which a blanket cylinder (B) for newspaper printing-a blanket cylinder (B) offset rotary press equipped with a metering roller type keyless inking system is provided with an ink supply amount adjusting device of the present invention. It is a figure.

FIG. 2 is an enlarged front view of main parts such as a control roller and a scraper blade.

FIG. 3 is an enlarged side view of FIG. 2;

FIG. 4 is an enlarged view of a tip portion of a scraper blade.

FIG. 5 is an explanatory view of the operation when the scraper blade is off.

FIG. 6 is an explanatory view of the operation when the scraper blade is on.

FIG. 7 is a front view of a conventional example.

[Explanation of symbols]

 1 Running Paper 2, 2 Blanket Cylinder 3, 3 Plate Cylinder 4 Ink 5 Ink Pan 6 Fan Ten Roller 7 Metering Roller 8 Doctor Blade 9 Ink Mixing Roller 10 Ink Drum 11 Ink Rolling Roller 12, 12 'Inking Roller 13 Control Roller 14 Scraper blade 16 Holder 17 Through shaft 18 Lever 19 Adjustment screw shaft W Dampening water device

Claims (4)

[Claims] 1. In a rotary press equipped with a metering roller type keyless inking system, a control is performed in which the surface of an ink roller in the middle of an ink supply course from an ink supply section to an ink forming roller is brought into contact with and rotates in a nip state. A roller and a scraper blade, which is provided with its tip in contact with substantially the entire width of the surface of the control roller, scrapes off a part of the ink film on the roller surface, and the tip of the scraper blade is the control roller. An ink supply amount adjusting device comprising: a support member that is displaceably supported at a position in contact with a surface and a position not in contact with the surface. 2. The ink supply amount adjusting device according to claim 1, wherein the ink roller is a metering roller. 3. The support member is capable of adjusting the degree of contact of its tip when the scraper blade is in a position in contact with the surface of the control roller.
Ink supply amount adjusting device described. 4. The scraper blade is formed of one elastic thin plate, and the tip end portion which comes into contact with the surface of the control roller is formed into a sawtooth blade having a predetermined pitch. Ink supply amount adjusting device described.