JP3016665B2 - Cooling roll control device for web printing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a cooling roll in a web printing machine, and is particularly useful when applied to control of a web printing machine in a slow mode and a low speed mode.

[0002]

2. Description of the Related Art FIG. 5 is an explanatory view conceptually showing an offset rotary printing press which is a web printing press. In the figure, 1 is an infeed roll, 2 is a cooling roll,
3 is a drag roll, 4 is four printing units 4a, 4
a printing unit having b, 4c, 4d, 5 a dryer, 6 a tension sensor for detecting in-feed tension, 7 a transmission mechanism for the in-feed roll 1, 8 a transmission mechanism for the cooling roll 2, and 9 a drag mechanism for the drag roll 3. Transmission mechanism, 10 is a main motor, 11 is a control unit, 12
Is a web, and 13 is a line shaft.

In such an offset rotary printing press,
The web 12 is transferred to the printing unit 4 via the infeed roll 1.
After a predetermined printing is performed by the printing unit 4, a drying process of the ink in the dryer 5 and a cooling process by the cooling roll 2 are performed, and then the printing is sent to a cutting unit (not shown) via the drag roll 3. It has become. The driving force at this time is transmitted to the infeed roll 1, the cooling roll 2 and the drag roll 3 from the main motor 10 via the line shaft 13 together with the printing units 4a to 4d via the speed change mechanisms 7, 8, and 9, respectively. I do. That is, the driving force of the web offset press is:
It is configured to distribute and supply to each part via one line shaft 13.

The control section 11 controls each section of the web offset printing press.

First, the control unit 11 controls the main motor 10 to slowly move each of the printing units 4a to 4d of the printing unit 4,
It is driven to rotate at three modes, low speed and high speed. The slack mode is a mode selected by pressing a slack button (not shown) of the control unit 11 when the web 13 is threaded, and is usually set to 8 rpm. The low-speed mode is a mode selected by pressing a low-speed button (not shown) of the control unit 11 when performing printing preparation such as cylinder insertion, ink application, water application, and the like, and is normally set to 40 rpm. In the high-speed mode, the control unit 1 performs the actual printing.
This mode is selected by pressing a high-speed button (not shown).

Second, the control unit 11 controls the speed change mechanisms 7, 8,
The rotation speeds of the in-feed roll 1, the cooling roll 2, and the drag roll 3 are controlled by controlling the motors 7a, 8a, 9a. There are two types of control in this case, tension control and lead control. The tension control is to control the rotation speed of the roll so that the tension of the web 13 becomes a preset tension value. Therefore, the tension sensor 6 for detecting the tension of the web 13 is required. By comparing the detected tension value with the set tension value, control is performed so that the two values match. On the other hand, the pulling rate control is to increase or decrease the rotation speed of the plate cylinder of the printing unit 4 (the rotation speed of this machine) by a constant ratio, and to control the rotation speed of the roll so as to reach the set speed in this manner. Is what you do. The setting of the trigger value is performed by operating an increase / decrease button (not shown) of the control unit 11.

The transmission mechanisms 7, 8, 9 are differential gear mechanisms. Therefore, regardless of the control of the tension and the pulling ratio, the motors 7a, 8a, 9a are controlled by a control signal from the control unit 11. By controlling the rotation, it is possible to control the in-feed roll 1, the cooling roll 2, and the drag roll 3 to a predetermined rotation speed.

[0008] The tension control and the pulling rate control are performed in order to apply an appropriate tension to the web 12. In the prior art, the infeed roll 1 controls the tension and the cooling roll 2 and the drag roll 3 control the tension. Lead control is performed.

[0009]

In the prior art as described above, since the cooling roll 2 controls the pulling rate in the entire rotation speed range of the web offset printing press, the cooling roll 2 is particularly suitable for the slow rotation mode, which is a low speed rotation range. When driving in the low-speed mode, there is a problem that running of the web 12 becomes unstable. This is for the following reason.

1) During preparation for printing in the low-speed mode,
The tension of the web 12 is apt to fluctuate due to, for example, insertion of the body.
That is, for example, before and after performing cylinder insertion (operation of bringing the blanket cylinder and the plate cylinder into contact with each other and sandwiching the web 12 between the upper and lower blanket cylinders), the tension applied to the web 12 fluctuates greatly, and the rotation speed is reduced. Along with the low speed, the tension fluctuation of the web 12 increases.

2) A roll (not shown) for pressing the web 12 against the cooling roll 2 is provided in the vicinity of the cooling roll 2, but this roll is attached to the cooling roll 2 at the time of slow motion. Not be. That is, since the web 12 does not come to the wearing state unless the printing mode is set, such as after the cylinder is loaded, the web 12 slips on the cooling roll 2 and the desired tension cannot be easily obtained by the pull rate control.

An object of the present invention is to provide a control apparatus for a cooling roll in a web printing machine capable of stabilizing the running of a web in a low-speed range in view of the above-mentioned prior art.

[0013]

According to the present invention, there is provided a printing apparatus for printing on a web printing machine which rotationally drives various rolls such as an infeed roll, a cooling roll and a drag roll together with a plate cylinder of a printing unit. In the cooling roll control device that cools the web after being printed by the unit and dried by the dryer, a cooling roll, and a drag roll disposed downstream of the cooling roll with respect to the web flow direction. And a tension sensor that detects the tension of the web during the rotation of the cooling roll so that the web printing machine has a predetermined tension value based on a tension value that is an output signal of the tension sensor in a predetermined low-speed rotation range. Tension control for controlling the rotation speed is performed, and the low speed rotation is controlled. At the high speed rotation range exceeding, characterized in that a control unit that performs discount rate control in which the plate cylinder cooling roll at a rotational speed obtained by adding a speed of constant predetermined ratio to the rotational speed of the controls to rotate.

[0014]

According to the present invention having the above-described structure, tension control is performed in a low-speed range. Therefore, even when the running speed of the web is low and the load acting on the web fluctuates, stable tension is maintained. Web running can be realized.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is an explanatory view conceptually showing an offset rotary printing press to which an embodiment of the present invention is applied. In the figure,
The same parts as those in FIG. 5 are denoted by the same reference numerals, and redundant description will be omitted. As shown in FIG. 1, the tension sensor 14 detects the web 1 between the cooling roll 2 and the drag roll 3.
The control unit 15 is configured to detect the tension of No. 2 and send a signal representing a tension value as an output signal to the control unit 15.

The control section 15 compares the tension value, which is the output signal of the tension sensor 14, with a preset tension value in addition to the function of the control section 11 shown in FIG. The transmission mechanism 8 is controlled via 8a. That is, the tension control is also performed for the cooling roll 2. The tension control of the cooling roll 2 is performed in the slow motion mode and the low speed mode by detecting that the slow motion button and the low speed button are pressed, and in both modes.

On the other hand, in the high-speed mode in which the high-speed button is pressed (during printing operation), the same trigger control as in the related art is performed.

The start and end of the tension control in the above embodiment are performed as follows.

As shown in FIG. 2, first, it is determined whether the tension control mode SW is ON or OFF (decision block 21).
reference). In the present embodiment, this is performed by detecting the operation states of the slow motion button and the low speed button. That is, the tension control mode SW is turned on when the slow motion button or the low speed button is pressed. Whether or not the control mode is the tension control mode can also be determined by detecting the rotation speed of the machine. That is, it is also possible to detect whether or not the rotation speed of the machine is equal to or lower than a predetermined rotation speed, and perform the tension control in this low rotation range.

If the result of determination in the determination block 21 is that the tension control mode SW is in the ON state, a tension control operation, which will be described in detail later, is started (see processing block 22).

If it is determined in the decision block 21 that the tension control mode SW is in the OFF state, it is decided whether or not the tension control operation is being performed (see the decision block 23). If the operation is detected, the tension control operation is terminated (see processing block 24).

FIG. 3 is a flowchart showing details of the processing of the processing block 22 in FIG. The tension control of the cooling roll 2 according to the present embodiment will be described in more detail with reference to FIG.

As shown in FIG. 3, first, the rotation speed of the cooling roll 2 is set to the minimum speed (processing block 31).
reference). Specifically, the rotation speed of the motor 8a is set to zero, and the control is performed at a pull rate of 1.

Next, it is determined whether or not the tension value detected by the tension sensor 14 has exceeded the upper limit value (see decision block 32). Thus, the rotation speed of the cooling roll 2 is controlled via the motor 8.

The tension value detected by the tension sensor 14 is compared with the set tension value, and the speed adjustment ratio of the cooling roll 2 is determined from the difference between the two. The rotation speed of the cooling roll 2 is determined according to the determined speed adjustment ratio. Control so that the real-time tension value approaches the set tension value (processing block 34).
reference).

At this time, a dead zone width is set for the set tension value, and it is determined whether or not the difference between the real-time tension value and the set tension value is within the dead zone (see the decision block 35).

If the result of the determination in the decision block 35 is that it is within the dead zone, the rotational speed of the cooling roll 2 is changed in accordance with a predetermined dead zone ratio (see processing block 36), and the set tension value is set. The same control is repeated until they match (see decision block 37).

If the result of the determination in the decision block 35 is that it is not a dead zone, the rotational speed of the cooling roll 2 is changed according to a predetermined ratio outside the dead zone (see processing block 38), and the same control is repeated.

As a result, the tension value of the web 12 between the cooling roll 2 and the drag roll 3 during the tension control has characteristics as shown in FIG.

[0031]

According to the present invention, as described above in detail with the embodiments, the tension of the cooling roll is controlled in the low-speed region of the printing press. Is constant, and stable running of the web is guaranteed even when an external force acts on the web.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram conceptually showing an offset rotary printing press in a state where an embodiment of the present invention is applied.

FIG. 2 is a flowchart showing the start and end of tension control according to the embodiment of the present invention.

FIG. 3 is a flowchart illustrating tension control according to the embodiment of the present invention.

FIG. 4 is a graph showing a tension characteristic of a web near a cooling roll in the control of FIG. 3;

FIG. 5 is an explanatory view conceptually showing an offset rotary printing press according to the related art.

[Description of Signs] 1 In-feed roll 2 Cooling roll 3 Drag roll 4a, 4b, 4c, 4d Printing unit 7, 8, 9 Transmission mechanism 12 Web 13 Line shaft 15 Control unit

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B41F 33/06 B41F 13/02 B41F 23/04 B41F 33/08

Claims (1)

(57) [Claims] 1. A web after being printed by said printing unit and dried by a dryer in a web printing machine for rotating and driving various rolls such as an infeed roll, a cooling roll and a drag roll together with a plate cylinder of the printing unit. A control device for controlling the cooling roll, the tension sensor detecting a web tension between the cooling roll and a drag roll disposed downstream of the cooling roll with respect to the flow direction of the web; In a predetermined low-speed rotation range, the printing press performs a tension control for controlling the rotation speed of the cooling roll based on a tension value, which is an output signal of the tension sensor, so as to have a preset tension value. In the high-speed rotation range, the rotation speed of the plate cylinder is Controller of the cooling roll in a web printing press, characterized in that it comprises setting the cooling roll at a rotational speed obtained by adding a speed of constant ratio that is a control unit that performs discount rate control for controlling so as to rotate.