JPH0444847A - Printing press - Google Patents

Abstract

PURPOSE:To reduce counteraction and the abrasion of a doctor blade and to also reduce replacing work by a method wherein the introducing speed of paper is set same to the rotary speed of an intaglio plate cylinder when the paper is introduced in such a state that printing pressure is applied and the rotary speed of the intaglio plate cylinder is set slow with respect to the introducing speed of the paper when the paper is introduced in such a state that the application of printing pressure is released. CONSTITUTION:The rotary peripheral speed of a plate cylinder 3 and the feed speed of paper (a) are set to a speed suitable for the printing of the same speed. Next, an impression cylinder 4 is lowered to apply printing pressure to the web (a) and the printing corresponding to predetermined length is applied to the paper (a). Continuously, the impression cylinder 4 is raised to release the printing pressure to complete printing. At this time, a rising signal is generated by an encoder corresponding to the terminal position of the printing image line formed to the peripheral surface of the plate cylinder 3 to perform the rising operation of the impression cylinder 4. Succeedingly, the plate cylinder 3 is cut off from a main motor M1 by a clutch 10 to release the rotary driving of the plate cylinder 3. The driving of the plate cylinder 3 is changed over to a sub-motor M2 by a clutch 12 to rotate the plate cylinder 3 at low speed. Continuously, the contact pressure (sliding pressure) of a doctor blade is lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a printing press that prints using a rotary intaglio printing method.

(Prior Art) Rotary intaglio printing machines include those that print sheet-fed paper and those that continuously print web paper (continuously rolled paper). In particular, the mechanism of a printing machine that prints web paper is that the web paper is usually introduced between the intaglio plate cylinder and the impression cylinder during printing, and the web paper is sandwiched between the plate cylinders and the peripheral speed of the plate cylinder. The circumferential speed of the impression cylinder is set to be the same as the introduction speed of the web paper introduced between both cylinders. The external feeding mechanism that feeds the web paper introduced between both cylinders (a mechanism that introduces and pulls the web paper between a pair of opposing nip rollers such as an infeed roller and an outfeed roller)
The rotation of both cylinders is synchronized and set at the same rotational circumferential speed.

By the way, this printing machine for web paper printing is used to print intermittently on the paper surface (for example, for the first few hundred meters of web paper, the application of printing pressure between the plate cylinder and the impression cylinder is released). By introducing the paper while it is still in place, the paper is fed in a blank state without printing.After that, printing is performed by applying printing pressure and introducing the paper for several meters, and then releasing the application of printing pressure again to leave a number of unprinted areas. In conventional printing machines, as mentioned above, due to the structure, the printing speed (at least the circumferential speed of the plate cylinder) and the introduction speed of the web paper to be printed are the same. As long as the web paper continues to be introduced, even if the printing pressure applied to the web paper by the plate cylinder is released, the plate cylinder will not be able to reach the corresponding speed. It continues to rotate at the same peripheral speed as the paper introduction speed.

(Object of the Invention) As described above, the web paper printing machine using the conventional rotary intaglio printing method is capable of controlling the circumferential speed of the plate cylinder and the printing paper ( web paper)
For example, if the paper feed speed (introduction speed) is increased in order to improve productivity, the rotational peripheral speed of the plate cylinder will increase accordingly, and as a result, the ink storage (ink fountain) will increase. The ink (in intaglio printing, ink diluted with an organic solvent is often used) is strongly circulated by the rotation of the plate cylinder, increasing the contact between the ink and the surrounding air, and causing the solvent in the ink to volatilize. This not only results in a loss of solvent, but also pollutes the surrounding air. Further, as the solvent volatilizes, the fluctuation in the increase in ink viscosity increases, making it difficult to maintain proper printing conditions, and increasing the frequency of work to keep printing conditions constant.

In addition, in the conventional printing press mentioned above, even while the application of printing pressure is released, the metal doctor blade for scraping ink does not come into sliding contact with the circumferential surface of the metal plate cylinder that rotates at high speed. Since this continues, there is a loss due to wear of the doctor blade and the peripheral surface of the plate cylinder.

Since the doctor blade is always in strong pressure contact with the circumferential surface of the plate cylinder, as the rotation speed of the plate cylinder increases, wear on both the doctor blade and the circumferential surface of the plate cylinder increases, making it impossible to scrape off ink evenly. As a result, ink tends to adhere to non-image areas other than image areas, which adversely affects printing quality and increases the frequency of replacing doctor blades and plate cylinders.

(Structure of the Invention) The present invention comprises a printing impression cylinder and an intaglio plate cylinder to which ink is supplied, a doctor blade for scraping ink is brought into sliding contact with the intaglio plate cylinder, and the impression cylinder is applied with printing pressure. In a rotary intaglio printing machine that prints by introducing web paper between the plate cylinder and the plate cylinder, when introducing the web paper with printing pressure applied,
The web paper introduction speed and the rotational speed of the intaglio plate cylinder can be set to the same speed, and when the web paper is introduced with the application of printing pressure released, the rotational speed of the intaglio plate cylinder is slower than the paper introduction speed. This printing press is characterized by being equipped with a mechanism that can set the speed or stop state.

The printing press of the present invention will be described in detail according to examples.

FIG. 1 is a side view illustrating the main parts of an embodiment of the apparatus of the present invention, where l is the spindle of the web paper on the infeed side (winding-in side), and 2 is the outfeed side (winding-up side). 3 is an intaglio plate cylinder, 3a is a plate cylinder axis, 4 is an impression cylinder, and 4a is an impression cylinder shaft; Some types of gears are engaged with each other and rotated in conjunction with gears, etc. 5 is a doctor blade that is in sliding contact with the circumferential surface of the plate cylinder 3; 6 is an intaglio ink reservoir; 7 is an intaglio ink (solvent-diluted printing ink); 8 is an infeed roller consisting of a pair of opposing rollers 8a and 8b. 9 is an outfeed roller consisting of a pair of opposing rollers 9a and 9b. One roller 8a of the infeed rollers and one roller 9a of the outfeed rollers are drive system rollers, and each is a facing roller 8.
b.

9b is in pressure contact with it and rotates as a result of rotation or meshingly rotates via a gear, and the web paper a is fed at a speed corresponding to the circumferential speed while being nipped by this pressing opposing roller that rotates at an appropriate circumferential speed. Operate, plate cylinder 3
and the impression cylinder 4.

The spindle 1 of the infeed inverted web paper is connected to a main motor M1 via a brake mechanism 11 for braking the rotation of the spindle 1 (to remove inertia) and a transmission C1, such as a line shaft, a gear, etc. are connected by. The drive system roller 8a of the infeed roller 8 is driven by a transmission C5
The rotating shaft 3a of the zero plate cylinder 3 is connected to the main motor M1 via a line shaft, gears, etc., and is connected to the main motor M1 via a clutch 10 and gears. Further, the plate cylinder rotating shaft 3a is coupled to a sub-motor M2 via a clutch 12 and a gear or the like. Further, the drive system roller 9a of the outfeed roller 9 is connected to a line shaft via a transmission C8.
It is coupled to the main motor M1 through gears or the like. The outfeed side web support shaft 2 is coupled to the main motor M by a line shaft, gears, etc. via a transmission C4. The impression cylinder 4 performs a pressing contact operation (solid line) and a separating operation (dotted line) against the circumferential surface of the plate cylinder 3 via the web paper by appropriate driving means (air cylinder, hydraulic cylinder, etc.).

Detection of this operating state of contact and separation is performed by a position detector (not shown) such as a limit switch or a microswitch as appropriate. Further, the plate cylinder 3 is immersed in printing ink 7 diluted to an appropriate viscosity with a solvent such as toluene stored in a printing ink reservoir 6, and while rotating clockwise in the drawing, a plate is made on the circumferential surface of the plate cylinder 3. While allowing the ink to adhere to the image area of the concave portion, the ink-scraping doctor blade 5 scrapes off the excess ink adhering to the circumferential surface of the plate cylinder 3, and the web paper a introduced between it and the impression cylinder 4 is removed. The printing ink filled in the recessed image area of the plate cylinder 3 is transferred to the plate cylinder 3.

The above is the main part of the printing machine of the present invention, and the main motor M1 that drives the entire printing machine drives the plate cylinder 3 and the web paper a.
This printing machine has a structure in which an infeed roller 8 and an outfeed roller 9, which are the feeding mechanism, are driven and rotated at the same time.

To explain the start-up preparation operation of the printing press of the present invention, first, the clutch 10 installed between the plate cylinder 3 and the main motor M1 is connected, and the clutch 12 of the sub-motor Mt is released. Next, the main motor M is started at a very low speed (slow speed). Then, the web paper a on the infeed side to be unwound is transferred between the opposing rollers of the infeed roller 8, between the plate cylinder 3 and the impression cylinder 4 in the separated state (dotted line), and between the opposing rollers of the out roller 9. The paper web is introduced, and the end of the paper web is wrapped and fixed around the support shaft 2 on the outfeed side. Next, while rotating at a very low speed, the web paper supported by the support shaft 1 on the infeed side and the infeed roller 8,
The rotational circumferential speeds of the web paper supported by the plate cylinder 3, the outfeed roller 9, and the outfeed side support shaft 2 are controlled by the respective transmissions C3, C+, C! , Ca to adjust the rotational peripheral speed of the plate cylinder 3 and the impression cylinder 4, and the rotational speed of both cylinders 3 and 3.
, 4, the feeding speed of the web paper a introduced between the two sheets is set to be the same to prepare for printing. In addition,
Before and after the infeed roller 8 or outfeed roller 9, there are tensions q for adjusting the tension of the web as appropriate.
installation roller (not shown). Next, the main motor M is set to increase its rotational speed to the normal printing rotation speed, and printing is started.

When feeding the web paper a during printing, to temporarily cancel printing, the web paper feeding drive system is rotated at the same peripheral speed, and the impression cylinder 4 is separated from the plate cylinder 3 (dotted line). After the application of the printing pressure to the web paper a between the plate cylinder 3 and the impression cylinder 4 is released (after the position detector detects the separation state of the impression cylinder 4 from the plate cylinder 3), the plate cylinder 3 and the main motor M
1, the connection operation of the clutch 10 installed between the plate cylinder 3 and the sub-motor M2, which is set to rotate at a low speed, is disconnected and the interlocking rotation of the two is interrupted. By operating the two in conjunction with each other, the rotation peripheral speed of the plate cylinder 3 can be brought to a low speed while only the web paper a is fed at the usual print feeding speed. Note that the rotation shaft 3a of the plate cylinder 3 has the following:
An encoder that can appropriately detect the rotational phase position is installed.

Next, another embodiment of the printing press of the present invention will be described in detail with reference to FIG.
Infeed motor M via a brake mechanism 11 for braking the rotation of the spindle (removing inertia) and a transmission C8.

The drive system roller 8a of the infeed roller 8 is connected to the infeed motor Mz by a line shaft, gears, etc. via a transmission CI. 3a is a plate cylinder rotation motor M by a gear etc. via a transmission C6.
It is connected to 5. Further, the drive system roller 98 of the outfeed roller 9 is coupled to the outfeed motor M4 by a line shaft, gears, etc. via a transmission C1. The outfeed side web support shaft 2 is coupled to the outfeed motor M4 by a line shaft, gears, etc. via a transmission C4. The infeed motor M is provided with an electric circuit 14 so as to rotate at a frequency of a predetermined ratio corresponding to a predetermined frequency for rotating the plate cylinder rotation drive motor Ms, and an open/close switching circuit 15 is provided in the circuit 14. Equipped with Also,
The infeed motor M and the outfeed motor M4 detect the tension of the web paper a to be fed, and issue a rotation control signal for each infeed motor M and outfeed motor M4 to adjust the tension. A run controller 13 is provided.

In this way, the plate cylinder rotation drive motor M and the web paper feeding motors M, M4 are separately provided, and the infeed motor is controlled at a predetermined ratio in response to the rotation of the plate cylinder rotation drive motor M. M, and also detects the tension applied to the feeding web paper a to determine the paper feeding speed (infeed roller speed), i.e., the winding side speed (outfeed roller speed) with respect to the infeed motor M, i.e. This is a printing machine that adjusts the driving rotation speed of the outfeed motor M4.

The printing press of the present invention makes the paper feeding speed and the circumferential speed of the plate cylinder the same during printing, and when printing pressure is released and only the paper is fed without printing, only the paper is fed at high speed. The plate cylinder 3 is rotated at a low speed to prevent the ink attached to the circumferential surface of the plate cylinder 3 from drying. If the plate cylinder is stopped when paper a is fed, abrasion of the circumferential surface of the plate R3 and the doctor blade 5 can be prevented, but the ink in the intaglio of the plate cylinder that is not immersed in the ink reservoir 6 will dry up, and the next When printing, the intaglio plate becomes clogged and printing becomes impossible. For this reason, to prevent the ink on the plate cylinder 3 from drying out, the plate cylinder 3 is always immersed in the ink in the ink reservoir 6.
It is necessary to prevent drying, and the plate cylinder must be kept rotating. Note that the method is not limited to this depending on the degree of dryness of the ink used.

The pressure of the doctor blade in contact with the plate cylinder when paper is fed (
Reduce the sliding contact force) to the minimum level that can scrape off the non-image areas of the plate cylinder, or separate the doctor blade 5 completely from the circumferential surface of the plate cylinder 3 to prevent wear of the plate cylinder and doctor blade. By suppressing this, when printing is started, the sliding contact force is restored to be appropriate for the predetermined printing.

The number of rotations of the plate cylinder that switches to low-speed rotation when feeding paper varies depending on the diameter of the plate cylinder used, and if the ink is scraped off with a doctor blade, the frequency of soaking in the ink reservoir will be relatively lower if the plate cylinder diameter is small. Although the circumferential speed may be slow, as the diameter of the plate cylinder increases, it is necessary to increase the circumferential speed to prevent ink from drying out adhering to the circumferential surface of the plate cylinder.

A peripheral speed of 10 to 30 m/win is appropriate for a plate cylinder of 200 mmφ.

Furthermore, the sliding force of the doctor blade against the plate cylinder when printing is not performed is substantially due to the doctor blade's own weight. The sliding contact force of the doctor blade varies depending on the plate cylinder diameter and the sliding contact angle of the doctor blade, but it is 0.1 to 1.
A sliding contact force of 0Kg/C- is applied to the minimum level of 0.0kg/C- for ink to be scraped off from the non-image area (non-image area) on the plate. OI
Lower it to about Kg/C-.

When paper is fed, if the doctor blade is separated from the plate cylinder and the pressure is completely zero, neither the plate cylinder nor the doctor blade will wear out, but in this state, the ink is not scraped off by the doctor blade, so the entire surface of the plate The plate cylinder rotates with a thick layer of ink adhered to the plate, and although this has the effect of delaying the drying of the ink inside the intaglio plate on the plate cylinder, the contact area between the ink and the surrounding air increases and the solvent in the ink evaporates. The effect obtained by lowering the rotational speed of the plate cylinder is halved.Whether or not to completely separate the doctor blade from the plate cylinder depends on the diameter of the plate cylinder, the depth of the ink reservoir (
volume of the plate cylinder immersed in ink), number of rotations of the plate cylinder,
Varies depending on ink viscosity, etc.

For example, in the case of a plate cylinder with a relatively short peripheral length, such as a plate cylinder diameter of about 100 to 200 mmφ, the sliding contact force of the doctor blade should be set to the minimum range that can completely scrape off the ink in the non-printing area. Better results can be obtained by setting the pressure to the limit and scraping off the ink on the plate. Plate cylinder diameter is 200mmφ
If the plate cylinder exceeds this point, it will take time for the scraped part of the plate cylinder to be immersed in the ink reservoir, making it more likely to dry out. Good results can be obtained by setting the speed at a low speed of 1 to 10 m/win to suppress the volatility of the ink solvent.

Next, an embodiment of printing using the printing press of the present invention will be described in accordance with the printing order.

(Example 1) Fig. 1 shows that the rotational circumferential speed of the printing plate cylinder 3 and the feeding speed of the web paper a are set to appropriate speeds for printing at the same speed.Next, the impression cylinder 4 is lowered and the web paper is Apply printing pressure to web paper a to print a predetermined length on web paper a.At this time, press the plate so that the image area at the printing start position on the circumference of plate cylinder 3 is printed on web paper a. An encoder can be installed on the rotating shaft 3a of the plate cylinder 3 to generate a lowering signal for the impression cylinder 4 in accordance with the printing start position of the printing image formed on the circumferential surface of the cylinder 3. Subsequently, the impression cylinder 4 is raised to release the printing pressure, and printing is completed. At this time, the encoder generates a rising signal for the impression cylinder 4 in accordance with the end point position of the printing image made on the peripheral surface of the plate cylinder 3, so that the impression cylinder 4 can be raised. Subsequently, the plate cylinder 3 is disconnected from the main motor M by the clutch 10, and the driving rotation of the plate cylinder 3 is released.

Then, the clutch 12 switches the drive of the plate cylinder 3 to a single sub-motor, and the plate cylinder 3 is rotated at a low speed. Subsequently, the contact pressure (sliding force) of the doctor blade 5 is reduced. To adjust the sliding contact force of the doctor blade 5, as shown in FIG. This is possible by providing it rotatably by a predetermined angle (for example, in the range of 5° to 10°) in the direction (separation direction).

Next, if necessary, increase the rotational speed of the main motor Ml to feed the paper a the required length at high speed.Next, before completing feeding the required length, the main motor Ml
1 to a speed suitable for printing, the drive of the plate cylinder 3 is switched from the sub motor M to the main motor M, and the circumferential speed of the plate cylinder 3 and the paper a are changed.
The doctor blade 5 is immediately rotated in the sliding direction to set a predetermined printing appropriate sliding contact force again. Printing is performed by repeating such operations.

(Example 2) Fig. 2. The feeding speed of the web paper a is regulated by the plate cylinder drive motor M, and the feeding speed of the paper a on the infeed side and the feeding on the outfeed side is controlled by the tension applied to the web paper a. The speed is regulated by circuit 14. next,
The rotational speed of the motor M is adjusted to set the plate cylinder 3 to a rotational circumferential speed appropriate for printing. Next, the impression cylinder 4 is lowered to perform printing, printing for a predetermined length is performed, and the impression cylinder 4 is lowered.
to finish printing. Subsequently, the switching circuit 15 is operated to electrically interrupt the circuit 14. By shutting off, the infeed motor M can be independently controlled while maintaining its rotation so as to maintain the feeding speed of the web paper a at the same speed as the plate cylinder 3. Subsequently, the plate cylinder 3 is separately set to a low speed rotation by the plate cylinder drive motor M, and is rotated at a low speed. Subsequently, the bracket 5a is rotated to move the doctor blade 5 away from the circumferential surface of the plate cylinder 3, or to reduce its sliding force.

Further, if necessary, the rotation of the infeed motor M3 is increased at high speed to feed the web paper a at high speed. Next, before the required length of web paper is completely fed, the web feeding speed is lowered to a speed appropriate for printing, and the rotation of the plate cylinder 3 is increased from a low speed to the same speed as the paper feeding speed. Subsequently, switching circuit W115 is operated to switch circuit 1.
After making the circuit 4 into a closed circuit, the peripheral speed of the plate cylinder 3 and the paper feeding speed are adjusted to a predetermined ratio and driven. Subsequently, the bracket 5a is rotated, and the sliding force of the doctor blade 5 is again set to the original sliding force. Thereafter, printing is performed by repeating this operation.

In the second embodiment, similarly to the first embodiment, the web paper a is placed between the plate cylinder 3 and the infeed roller 8 and between the plate cylinder 3 and the outfeed roller 9. or to lift the web paper a from the circumferential surface of the plate cylinder 3 so that it does not come into contact with the plate cylinder 3 after the impression cylinder 4 is raised and the application of printing pressure is released. It is possible to install guide rollers as appropriate.

(Action of the invention) The printing press of the present invention applies printing pressure between the plate cylinder and the impression cylinder,
When printing by introducing web printing paper, the introduction speed of the web paper and the rotational circumferential speed of the plate cylinder of the printing machine are set to the same speed. When releasing the printing pressure between the impression cylinder and introducing the web paper and letting it pass through without printing, at least the rotational peripheral speed of the plate cylinder should be set to a speed slower than the introduction speed of the web paper. Since the can be set to a stopped state, it is possible to avoid reducing the amount of solvent ink in the ink reservoir that is circulated more strongly than necessary while the web paper is being air-flowed. Contamination can be avoided. Further, unnecessary wear of the doctor blade and the peripheral surface of the plate cylinder can be avoided, good printing quality can be maintained, and replacement work can be reduced.

(Effects of the Invention) The printing press of the present invention reduces the wear of the plate cylinder and doctor blade, which reduces replacement work.Also, since the wear of the doctor blade is reduced, ink can be scraped off smoothly. Capture of ink during printing due to insufficient ink does not occur, a good printing condition can be maintained, and workability is improved. In addition, when the printing pressure is released, the plate cylinder rotates at a low speed, which reduces the amount of ink that is removed by fusing and volatilizing more than necessary when the paper is passed through the air, reducing the number of times that solvent needs to be regularly refilled. This method has remarkable effects such as reducing the labor and cost involved, reducing the smell of solvents in the surrounding area, and improving the working environment.

[Brief explanation of the drawing]

FIG. 1 is a side view of the main parts of one embodiment of the printing press of the present invention, and FIG. 2 is a side view of the main parts of another embodiment of the printing press of the invention. 1... Infeed side web support shaft 2... Outfeed side web support shaft 3... Plate cylinder 4... Impression cylinder 5
...Doctor blade 5a...Bracket 6.
・・Ink storage 7・Ink 8・Infeed roller 9・Outfeed roller 10・
...Clutch 11...Brake mechanism 12...Clutch 13...Tension controller 14...Motor rotation speed regulation circuit 15...Switching circuit a...Web paper C9-C4...Transmission M I ”
”'Ms...Motor patent issued
Kazuo Suzuki, Representative of Toppan Printing Co., Ltd.

Claims (1)

[Claims] 1) comprising a printing impression cylinder and an intaglio cylinder to which ink is supplied,
In a rotary intaglio printing machine in which a doctor blade for scraping ink is brought into sliding contact with the intaglio plate cylinder, and a web paper is introduced between the impression cylinder and the plate cylinder to which printing pressure is applied for printing, the printing pressure is applied. When introducing web paper with printing pressure applied, the web paper introduction speed and the rotation speed of the intaglio plate cylinder can be set to the same speed, and when introducing web paper with printing pressure released, the rotation speed of the intaglio plate cylinder can be set to the same speed. A printing machine characterized by being provided with a mechanism that can set the rotation of the cylinder to a speed slower than the paper introduction speed or to a stopped state. 2) The doctor blade, which operates in sliding contact with the intaglio plate cylinder, reduces its sliding pressure or releases its sliding operation when the application of printing pressure is released. The printing machine according to item 1.