JPH0321349B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing press, and particularly to an ink dispenser roller in which an ink reservoir having a small gap is formed around the circumference of the ink dispenser roller, and an ink dispenser roller operation control device for guiding ink through the gap. It is related to.

First, let's talk about offset printing machines.
As shown in FIG. 1, a typical offset printing press is comprised of a plurality of printing units 1A to 1D that perform printing processes in, for example, black, indigo, red, and yellow from the front stage. Each of the printing units 1A to 1D is provided with a printing mechanism 2 for the upper and lower surfaces of the printed matter P, respectively. As shown in FIG. 2, the printing mechanism 2 has an ink reservoir member 12 arranged in an inclined manner on the circumferential surface of an ink fountain roller 11 that is continuously rotated by, for example, a DC motor, and a slight gap 13 at the tip thereof. Ink dispenser roller 1
A kneading roller 14 is provided at a position apart from 1. Kneading roller 14 and ink dispenser roller 1
1, an ink transfer roller 16 is provided at the other end of a swinging arm 15 that performs swinging motion using one end as a fulcrum. On the other hand, with respect to the kneading roller 14, a forming roller 17, a plate cylinder 18, and a blanket cylinder 19 that contacts the printed matter P are arranged so as to rotate while slidingly contacting the same in sequence. Here, when the number of rotations of the plate cylinder 18 is N ₀ , the oscillation period of the transfer roller 16 is predetermined in a certain relationship to be, for example, 0.18N ₀ .

Therefore, when the ink dispenser roller 11 rotates,
The ink stored in the ink reservoir member 12 is
The ink is drawn out through the gap 13 while being substantially uniformly adhered to the circumferential surface of the ink dispenser roller 11 , and then transferred to the kneading roller 14 via the ink transfer roller 16 . The ink transferred to the mixing roller 14 is transferred to the blanket cylinder 19 via the applicator roller 17 and the plate cylinder 18. As a result, the printed matter P in contact with the blanket cylinder 19 is printed in a predetermined color. In this case, the amount of ink is adjusted by the speed of the ink dispenser roller 11 and the gap 13.

The problem here is that the gap 13, which is set in relation to the amount of ink, is usually several tens of micrometers, so if the paper quality of the printed material P is prone to paper dust, the gap 13 will be clogged with paper dust. This is the point. In other words, if the printed material P is a material that easily generates paper dust, such as newspaper, the paper dust will first adhere to the blanket cylinder 19 through contact with the blanket cylinder 19, and the paper dust will be deposited on the plate cylinder 18 and the paper dust. roller 17, kneading roller 14,
As a result of the ink being mixed in the ink in the ink reservoir member 12 through the transfer roller 16 and the ink dispenser roller 11, the gap 13 becomes clogged with paper powder. If the gap 13 is clogged with paper powder or the like, printing unevenness will occur locally and the quality of the printed matter will deteriorate.

For this reason, conventionally, an operator periodically inserts a relatively thin plate-shaped spatula into the gap 13 to remove paper dust and other debris that is clogging the gap 13.
The number of times the spatula is inserted into the gap 13 is determined to be an appropriate number based on past experience and the like depending on the printing situation. That is, the number of times is increased for printed materials such as newspapers that tend to generate paper dust, and the number of times is also increased when the ink viscosity is high or the printing speed is high.

However, such a method is not only dangerous because it is carried out while the machine is in operation, but also places a heavy burden on the worker, resulting in extremely low work efficiency.

SUMMARY OF THE INVENTION An object of the present invention is to provide an operation control device for an ink dispenser roller in a printing press in which dust is removed periodically without requiring the operator to remove dust as described above.

Therefore, in the present invention, a drive device that intermittently changes the rotation of the ink dispenser roller is provided as a drive source for the ink dispenser roller, thereby utilizing the impact generated when the rotation of the ink dispenser roller changes suddenly. The purpose of the present invention is to automatically remove paper dust and other debris that gets stuck in the gap between the ink fountain roller and the ink reservoir member, thereby achieving the above object.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In this embodiment, the drive section 21 shown in FIG. 3 is used as the drive source for the ink dispenser roller 11 shown in FIGS. 1 and 2, and the drive section 21 is controlled by the control circuit 31 shown in FIG. 4. That's what I do.

The drive unit 21 connects a DC motor 2 to the frame 22 of the printing unit via a bracket 23.
4 and a clutch device 26 for intermittently transmitting the rotation of the DC motor 24 to the ink fountain roller 11 through a speed reducer 25. The clutch device 26 includes an electromagnetic clutch 2
7 and an electromagnetic brake 28 are built-in.

As shown in FIG. 4, in the control circuit 31, a motor control relay 34 is connected between AC100V power terminals 32A and 32B when the drive circuit of the DC motor 24 is opened and closed via a switch 33. A power supply terminal 35A of preset counter 35 and clutch controller 42 are connected. A timer 37 that is reset by a signal from an output terminal 35B of the preset counter 35 and a series circuit of a normally open contact 37A of the timer 37 and a first relay 38 are connected to the control relay 34 in parallel, respectively. ing. Further, the preset counter 35 has its input terminal 35C connected to a normally open contact 41A of a second relay 41, which will be described later.
When the normally open contact 41A is closed a preset number of times, a set signal is applied from the output terminal 35B to the timer 37, and the timer 37 is reset.

Furthermore, DC24V DC power terminals 39A, 39B
A power supply terminal 40A of the proximity switch 40 is connected between them. The proximity switch 40 is connected to the transfer roller 1
It detects the timing when the roller 6 comes into contact with the ink dispenser roller 11, and is installed in the state shown in FIG. That is, the rotating shaft 51 rotates at a rotational speed of, for example, _{0.18N0 relative to the rotational speed N0 of} the plate cylinder 18, that is, in synchronization with the oscillation period of the transfer roller 16.
A rectangular proximity body 52 with both ends protruding is provided for each printing unit so that the angle can be adjusted freely, and a proximity switch 40 is provided across both ends of the proximity body 52 at a position where both ends of each proximity body 52 pass. The structure is In other words, the oscillating motion of the transfer roller 16 is replaced by the rotation of the rotating shaft 51, and the angular position of both ends of the proximal body 52 provided on the rotating shaft 51 is detected by the proximity switch 40.
This structure detects the timing when the ink dispenser 6 comes into contact with the ink dispenser roller 11. Here, the proximal body 5
By adjusting the angle in step 2, a detection pulse is output from the output terminal 40B of the proximity switch 40 when the transfer roller 16 comes into contact with the ink dispenser roller 11. A normally open contact 38A of the first relay 38 and a second relay 41 are connected in series between the output terminal 40B of the proximity switch 40 and one power supply terminal 39B. Further, both power supply terminals 40A of the proximity switch 40 are connected to the first
Through a parallel circuit between the normally open contact 38B of the relay 38 and the normally open contact 41B of the second relay 41,
A control signal terminal 42A of the clutch controller 42 is connected. A clutch controller 42 operates the power supply clutch 27 when on and operates the electromagnetic brake 28 when off.

Next, the operation of this embodiment will be explained.

Now, when the switch 33 is closed, the DC motor 24 rotates via the motor control relay 34, and the timer 37 is activated. Then, by closing the normally open contact 37A of the timer 37, the first relay 38 is energized, so its normally open contact 38A is opened, and its normally closed contact 38B is closed. When the normally open contact 38B is closed, the clutch controller 42 is turned on and the electromagnetic clutch 27 is actuated. As a result, the rotation from the DC motor 24 is transmitted to the ink dispenser roller 11 via the crack device 26, and the ink dispenser roller 11 rotates. During this time, the ink drawn out from the ink reservoir member 12 by the rotation of the ink dispenser roller 11 is transferred to the kneading roller 14 by the transfer roller 16, and then transferred to the blanket cylinder 19 via the form roller 17 and the plate cylinder 18. It will be done.

In this state, when the timer 37 has elapsed for the set time t, the timer 37 is turned off and the contact 37A, which has been closed until now, is opened. Then, the first relay 38 is demagnetized, so the contact 38A is closed and the contact 38B is opened. When contact 38B is opened, clutch controller 42 is turned off, resulting in
The electromagnetic clutch 27 is opened and the electromagnetic brake 28 is activated. As a result, the rotation from the DC motor 24 is no longer transmitted to the ink dispenser roller 11, and the ink dispenser roller 11 stops. On the other hand, each time the transfer roller 16 comes into contact with the ink dispenser roller 11 due to the oscillating movement of the oscillating arm 15, the proximity switch 40
A detection pulse is output from the output terminal 40B. At this time, when the ink dispenser roller 11 is stopped, the contact 38A is closed, so the second relay 41 is energized for a certain period of time. While the second relay 41 is energized, its contacts 41B are closed, thereby turning on the clutch controller 42, which activates the electromagnetic clutch 27 and disables the electromagnetic brake 28. As a result, the rotation from the DC motor 24 is transmitted to the ink dispenser roller 11, and the ink dispenser roller 11 rotates for a certain period of time, that is, while the transfer roller 16 is in contact with it, and then stops. At this time, when the ink dispenser roller 11 starts to rotate from a stopped state, the impact causes the dust such as paper powder stuck in the gap 13 to be removed while remaining attached to the ink dispenser roller 11. . A portion of this removed dust adheres to the ink transfer roller 16, as in the case of removal using a conventional spatula, and then is deposited on each of the rollers 14, 17, 18,
19 and is transferred to the printed matter P. Therefore, in the case of printed matter P such as newspaper that easily generates paper dust, there is no particular problem in terms of print quality since the beauty of the print does not become a problem when paper dust is printed on newspaper. On the other hand, if the debris remains clogged, the gap 13
This causes unevenness in the ink that adheres to the ink dispenser roller 11, which poses a quality problem, but there is no problem if it is removed by impact as in this embodiment.

In this way, each time the transfer roller 16 contacts the ink dispenser roller 11, the ink dispenser roller 11
rotates intermittently for a certain period of time, and dust is removed by impact.

On the other hand, the transfer roller 16 is
When the second relay 41 is energized for a certain period of time each time the second relay 41 comes into contact with the contact point 41A, the contact point 41A is also closed each time. Then, the preset counter 35 closes its contact 41.
The input given by closing A is counted, and when it reaches a preset number, a set signal is output from the output terminal 35B. This causes the timer 37 to operate again, and the above-described operation is repeated.

In short, as shown in the sixth time chart, the ink dispenser roller 11 continues to rotate for the time t set by the timer 37 with the clutch 27 turned on, and then stops. After repeating the rotation operation for a certain period of time each time 16 comes into contact, the rotation is continued again for a set time t. Therefore, since the ink dispenser roller 11 is rotating at least while the transfer roller 16 is in contact with the ink dispenser roller 11, the supply of ink is not interrupted, and the paper dust and other debris that has accumulated in the gap 13 can be removed. can also be removed periodically.

In the above embodiment, the rotation from the DC motor 24 is intermittently transmitted to the ink fountain roller 11 by the clutch device 26. A motor may be connected and the rotation of the servo motor may be directly controlled. Further, even if a servo motor capable of forward and reverse rotation is used and the servo motor is controlled to rotate in the reverse direction for a fixed period of time every time the servo motor is rotated in the forward direction for a predetermined period of time, the same curing as in the above embodiment can be expected. Further, the rotation control of the ink dispenser roller 11 is not limited to stopping or reversing as described above, but also includes cases where the rotation speed is suddenly changed. At this time, ink dispenser roller 1
The degree of change in rotation in step 1 is determined depending on the material of the printed matter, printing speed, ink type (mainly ink viscosity), etc., as can be easily inferred from the frequency of dust removal operations using conventional spatulas. .
For example, when it comes to printed matter, if the printed material is hard to generate paper dust, such as high-quality paper, the number of changes is small, and if the printed material is easily generated, such as newspaper, it is increased. It also changes depending on the printing speed and type of ink, but these are determined by trial and error through experiments. Also, when the ink dispenser roller 11 is reversed, depending on the size of the gap 13, the roller 1
Although interference between the ink reservoir member 1 and the ink reservoir member 12 may be considered, it goes without saying that in an actual apparatus, the reverse operation is only performed when the gap 13 is large enough to cause no problem in reversing the ink reservoir member 12.

As explained above, according to the present invention, dust such as paper powder that is stuck in the gap between the ink fountain roller and the ink reservoir member is periodically removed by actively changing the rotation speed. This has the effect of providing an operation control device for an ink dispenser roller that does not require removal work by an operator as in the prior art.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the entire system of a general printing press, FIG. 2 is an explanatory diagram showing its printing mechanism, and FIGS. 3 to 6 show an embodiment of the present invention. Fig. 3 is a partially cutaway front view showing the drive unit, Fig. 4 is a circuit diagram showing the control circuit, Fig. 5 is a front view showing the installation state of the proximity switch, and Fig. 6 is a time chart. . DESCRIPTION OF SYMBOLS 11... Ink dispenser roller, 12... Ink reservoir member, 13... Gap, 19... Cylinder, 21... Drive section, 24... Motor, 26... Clutch device,
31...Control circuit.

Claims (1)

[Scope of Claims] 1. An ink reservoir member is disposed with a slight gap to the outer peripheral surface of the ink fountain roller, and the ink stored in the ink reservoir member is drawn out by rotation of the ink fountain roller, A printing machine in which printed matter is deposited on a cylinder in contact with the printed matter, characterized in that a drive device having an independent drive motor and intermittently changing the rotation of the ink dispenser roller is provided as a drive source for the ink dispenser roller. Ink dispenser roller operation control device. 2. In claim 1, the drive device includes a motor, a clutch device connected between the motor and the ink fountain roller, and a clutch device that intermittently controls the operation of the clutch device and controls the operation of the clutch device intermittently. and a control circuit for intermittently transmitting the rotation of the ink dispenser roller to the ink dispenser roller in a printing press. 3. An operation control device for an ink dispenser roller in a printing press according to claim 1, wherein the drive device includes a motor capable of reversible movement and a control circuit for intermittently reversing the rotation of the motor.