JP2000127352A - Apparatus and method for controlling web tension for rotary press - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus and a method for controlling a web tension for a rotary press capable of reducing material expenses and improving productivity, by shortening a time until becoming a specified tension, and remarkably reducing a spoilage generating at the time of starting. SOLUTION: The apparatus for controlling a web tension of a rotary press comprises an infeed unit 2 having a motor 13 provided at an inlet side of a printing unit 3 and independent from a driving system of a printer body and a function for controlling a web tension, a web tension detector 32 provided at an upstream side of a folding unit 6 to detect the web tension, and a folding unit tension giving unit 33 provided at an upstream side of a paper cutter of the unit 6, having a motor 10 independent from the driving system of a folding unit body and a function of controlling the web tension based on a detection signal from the detector 32 while holding a web 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a web tension control apparatus and a web tension control method which are installed in a rotary printing press and apply an initial tension to a web when the machine is restarted after stopping.

[0002]

2. Description of the Related Art FIG. 4 is a schematic diagram illustrating a main part of a web tension control device of a conventional general commercial web offset press, and FIG. 5 is a schematic diagram illustrating a defect in the web tension control device. FIG. As shown in FIG. 4 and FIG. 5, a general commercial rotary offset printing press includes a sheet feeding unit 1, an infeed unit 2, a printing unit 3, a cooling unit 4, a web path unit 5, a folding unit 6, and the like. The control unit 7 and the like, which are appropriately controlled, are configured as main components.

The paper feeding section 1 includes a reel stand 18 on which a roll-shaped web 22 is mounted, and functions to connect the new and old webs to each other and continuously feed the web 8 during printing operation. are doing. The infeed section 2 is a section for continuously drawing out the web 8 from the web 22 and serves as a means for appropriately controlling the web tension (web tension) downstream.
5, a fulcrum shaft 16, a balance weight roller arm 17, and an air cylinder 21. And web 8
The infeed roller 12 for holding and rotating the infeed roller is connected via a continuously variable transmission 23 to a main drive shaft 19 for interlocking the entire printing press so that the rotational drive force from the main drive shaft 19 is transmitted. It has become.

In the printing section 3, a plurality of sets of printing apparatuses 24a to 24d having different ink colors are usually arranged side by side in the web running direction. In the printing section 3, the web 8 is printed by the printing apparatuses 24a to 24d. The multi-color printing can be performed by sequentially passing the sheets through the printer. Then, the web 8 that has been printed in the printing unit 3 is heated and dried in a drying unit (not shown) in the next step, and then cooled in the cooling unit 4 and transferred to the web pass unit 5, where it is folded. It is cut and folded at. The web 8 in the folding unit 6 is vertically folded in two via a triangular plate (forming) 25, and then a lead-in roller 26 (26 a, 26 b) and a first nipping roller 9 are formed.
(9a, 9b) and the second nipping roller 27 (27
a, 27b) are sequentially cut at a predetermined position and folded to form a desired signature.
It is designed to be carried out.

Next, a conventional web tension control device and control method will be described. In the rotary printing press, when printing of the current order is completed, the machine is stopped and washed, and the printing wound on the plate cylinder is replaced, and other preparations for the next order are performed. In this case, the web path line on which the web 8 runs is free to release the engagement (nipping) of the blanket cylinder and the nip rollers 9a, 9b, 27a, 27b of the folding unit 6. Therefore, the tension acting on the web 8 that has passed through the web 8 is lost, and the web 8 is in a relaxed state (W in FIG. 5). When printing is restarted from such a state, there occurs a problem that the printing position shifts in the vertical direction or the processing position shifts for a long period of time when cutting or folding the web 8 in the folding unit 6.

[0006]

Therefore, in the above-mentioned conventional apparatus, when starting reprinting due to an order change or the like, first, the first and second nipping rollers 9 and 27 of the folding unit 6 are engaged. Then, the web 8 is transported downstream as usual, and the continuously variable transmission 23 of the infeed section 2 is set at a low speed to reduce the feed amount. In other words, the tension of the web 8 is gradually increased by the difference in traveling speed between the downstream side and the upstream side of the web 8, and regular printing can be performed when the web 8 reaches the specified tension. Therefore, it takes much time for the web tension to reach the specified tension, and the web travels (consumed) during that time.
All the webs 8 become waste. For this reason, in the conventional apparatus, there is a problem that not only the productivity is reduced, but also the loss of the material (rolled paper) is increased, resulting in an increase in production cost.

[0007] The present invention has been made in view of such circumstances, and an object thereof is to shorten the time required to reach a specified tension and to greatly reduce the waste paper generated at the start. Another object of the present invention is to provide a web tension control device and a web tension control method for a rotary printing press capable of reducing material costs and improving productivity.

[0008]

According to the present invention, there is provided a drive unit provided at an entrance side of a printing unit and independent of a drive system of a main machine body. An infeed section having a function of performing web tension control; a web tension detecting section provided upstream of the folding section to detect web tension; and a main body provided upstream of a cutting device of the folding section. And a folding unit tension applying section having a function of performing web tension control based on a detection signal from the web tension detecting section while nipping the web.

According to the present invention, there is provided an infeed unit which is provided at an entrance side of a printing unit, has driving means independent of a driving system of a main machine main body, and has a function of controlling web tension. Provided on the upstream side of the cutting device of the unit, having driving means independent of the driving system of the main machine main body, and holding the web based on a detection signal of a web tension detecting unit provided upstream of the folder unit while holding the web. After the tension control unit having the function of performing tension control and the tension control unit starts tension control, the rotary press is accelerated.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on illustrated embodiments. Here, FIG. 1 is an overall schematic configuration diagram of a web tension control device installed in a commercial offset rotary printing press according to a first embodiment of the present invention, and FIG. 2 is a functional explanatory diagram of the web tension control device. First of the present invention
As shown in FIG. 1, the commercial offset rotary printing press according to the embodiment includes a paper feeding unit 1, an infeed unit 2, a printing unit 3, a drying unit 30, a cooling unit 4, a web path unit 5, a folding unit 6, and The control section 7 controls the printing at an appropriate timing. The printing section 8 performs predetermined printing on the web 8 continuously fed from the sheet feeding section 1 and then cuts the sheet at the folding section 6 in the final process. At the same time, it is formed on a signature 31 having a predetermined shape (see FIG. 3), and is carried out to the outside.
These series of configurations and functions are the same as those described in the section of the related art.

In the rotary printing press of the present embodiment, a web tension control device is provided as a new mechanism in addition to the above configuration. The web tension control device is provided at the entrance side of the printing unit 3 and has an infeed unit 2 having a driving unit independent of a driving system of the main machine main body and having a function of performing web tension control; Installed upstream of
A web tension detecting unit (detector) 32 for detecting web tension, and a driving unit provided upstream of a cutting device (not shown) of the folding unit 6 and independent of a driving system of the main machine main body; A folding machine tension applying section (folding machine tension applying device) 33 having a function of performing web tension control based on a detection signal from the web tension detecting section 32 while holding the web 8 is provided.

The infeed section 2 has an infeed roller 12 for applying tension to the web 8 fed to the printing section 3.
The infeed roller 12 is configured to be separated from the drive system of the printing press main body (main machine main body) and to rotate via a motor (drive means) 13 that can be driven independently. ing. The motor 13 of the in-feed unit 2 is of a type having a function of freely switching between forward rotation and reverse rotation and having a function of freely setting a rotation speed. In addition, a pair of pretension rollers 11 (11
a, 11b). These pretension rollers 11a and 11b are located on the downstream side of the web path line near the pair of first nip rollers 9a and 9b provided in the folding unit 6, and are driven by the folding machine main body (main machine main body). It is configured to rotate via a motor (drive means) 10 that can be driven independently and at any rotational speed. Further, the web tension detecting unit 3
Reference numeral 2 denotes a tension pickup device 14 that is provided upstream of the folding unit 6 and measures the web tension immediately before reaching the folding unit 6.

In FIG. 1, reference numeral 15 denotes a balance weight roller for appropriately controlling the tension of the web 8 conveyed to the printing section 3.
Is rotatably attached to one end of the balance weight roller arm 17. The other end of the balance weight roller arm 17 is swingably supported by a fulcrum shaft 16 and has an air cylinder 21 at the center thereof.
Are connected. That is, the balance weight roller 15 controls the supply amount of the web 8 fed through the in-feed roller 12, and the balance weight roller arm 17 swinging about the fulcrum shaft 16.
Is maintained in a horizontal position by the air cylinder 21 so that the target tension of the web 8 is regulated.

The web tension controller of the present embodiment operates as follows when the printing press is restarted after stopping the rotary printing press for order change or other reasons. As shown in FIG. 2, first, the pair of first nipping rollers 9a and 9b are released from engagement with the printing machine stopped, and the printing rollers 11a and 11b are moved closer to each other to clamp the web 8. Subsequently, the pretension rollers 11a and 11b are driven, and the web 8 is rotated and transported while nipping the web 8, thereby pulling the web 8 and applying tension to the downstream side. The tension of the web 8 is detected by the tension pickup device 14,
The control signal is fed back to the drive motor 10 of the pretension roller 11 via the control unit 7 and is controlled. On the other hand, the infeed roller 12 provided in the infeed section 2 on the upstream side is once inverted from a stopped state,
By pulling back the web 8 to the reel stand 18 side, tension (back tension) is applied to the web 8. The tension of the web 8 is controlled by a balance weight roller 15, that is, by maintaining a horizontal state of an arm 17 on which the balance weight roller 15 is mounted. Then, the drive motor 13 is stopped.

As described above, the web tension control device according to the first embodiment of the present invention operates the rotary printing press by the motor 13 driving the in-feed roller 12 and the motor 10 driving the pretension roller 11. The web 8 has been configured so that a predetermined tension can be set on the web 8 that has been previously passed. After the initial tension is set, the printing press is started. The first nip roller 9 and the pre-tension roller 11 of the folder 6
Are in contact with each other at the time of starting the printing machine, that is, driven in a state where the web 8 is sandwiched, and after being accelerated to a predetermined rotation speed, a pair of pretension rollers 11
a and 11b are released. Then, the rotary printing press starts printing at an early stage when it starts accelerating. On the other hand, the infeed roller 12 controls the motor 13 after the printing press starts in the same manner as in the conventional machine, and controls the web 8 to be fed to always apply a predetermined tension.

As described above, the web tension control device of the present embodiment has the above-described configuration and function, and applies a tension corresponding to a specified value to the web 8 in advance as preparation for starting printing. be able to. Therefore,
It is possible to run the web 8 with a specified tension immediately after the start of the machine, to eliminate problems such as initial printing misalignment, and to accurately match the cutting position and the folding position in the folding unit 6. In this printing machine, it is possible to greatly reduce the waste paper generated before reaching the normal operation state. In addition, various effects can be obtained, such as reduction of material costs and improvement of productivity.

FIG. 3 is an explanatory view of a main part of a web tension control device installed in a commercial offset rotary printing press according to a second embodiment of the present invention. As shown in FIG. 3, a folding machine tension applying mechanism 44 is provided in the folding machine tension applying section 43 of the web tension control device according to the present embodiment, instead of the first nip roller 9 provided in the folding machine section 6. ing. The folder tension applying mechanism 44 includes a pair of forming rollers 49 (49a, 49a).
49b) and the rotational drive system of the forming rollers 49a, 49b can be separated from the interlocking main drive shaft 19 (see FIGS. 4 and 5) of each unit provided in the printing press, and can be driven independently and at an arbitrary rotational speed. A motor 20 is provided, and the forming rollers 49a and 49b are configured to rotate via the motor 20. Other configurations and functions of the paper feeding unit 1, the infeed unit 2, the printing unit 3, the cooling unit 4, the web path unit 5, and the like are the same as those in the first embodiment.

Since the web tension control device according to the present embodiment is configured as described above, after stopping the rotary printing press for an order change or other reasons,
To resume printing, the following operation is performed. First, in a state where the printing press is stopped, the forming rollers 49a and 49b are approached to sandwich the web 8,
Thereafter, the forming rollers 49a and 49b are driven, and the web 8 is pulled by rotating and transporting the web 8 while pinching the web 8, thereby applying tension to the downstream side. The tension of the web 8 is controlled by the tension pickup device 1
4 and is fed back to the drive motor 20 of the forming roller 49 via the control unit 7 to be controlled. On the other hand, as in the first embodiment, the infeed roller 12 provided on the upstream infeed portion 2 is once inverted, and the web 8 is pulled back to the reel stand 18 side, thereby adding back tension to the web 8. .

The tension of the web 8 is controlled to a specified value by maintaining a horizontal state of the balance weight roller arm 17 on which the balance weight roller 15 is mounted. In other words, the balance weight roller arm 1 which has been lowered as indicated by the dashed line in FIG. 2 due to the slack of the web 8 when the printing press is stopped.
Numeral 7 is lifted by an increase in tension generated due to a difference between the web running speed and the paper feeding speed to the downstream side, reaches a specified tension at a solid line (horizontal position), and stops the motor 13 in the same state. The illustrated web tension adjusting device of this embodiment is configured to be able to set an arbitrary value by changing and adjusting the air pressure applied to the air cylinder 21.

As described above, the web tension control apparatus according to the second embodiment of the present invention operates before the rotary printing press is operated by the motor 13 for driving the in-feed roller 12 and the motor 20 for driving the forming roller 49. A predetermined tension is set in advance on the web 8 that has passed through the printer, and the printing press starts after the initial tension is set. Since the infeed roller 12 and the forming roller 49 perform tension control even when the printing press is started, the infeed roller 12 and the forming roller 49 are controlled to correspond to the operating speed of the printing press, that is, to operate in conjunction with the rotation speed.

As described above, the web tension control device of the present embodiment has the above-described configuration and function, and, as in the first embodiment, corresponds to the specified value on the web 8 as preparation before restarting printing. Tension can be applied. Therefore, according to the web tension control device of the present embodiment, the productivity can be improved, and the waste paper generated at the start can be significantly reduced.
Various effects common to the embodiment can be obtained.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes may be made without departing from the gist of the present invention. What you get

[0023]

As described above, the web tension control device for a rotary printing press according to the present invention is provided at the entrance side of the printing section, has a driving means independent of the drive system of the main machine main body, and controls the web tension. And a web tension detector provided upstream of the folding unit to detect web tension, and a drive system of the main machine main body provided upstream of the cutting device of the folding unit. And a folding machine tension applying section having a function of performing web tension control based on a detection signal from the web tension detecting section while nipping the web. Can be eliminated, the time required for the web to reach the specified tension can be shortened, and the waste paper generated at the start can be greatly reduced. Improved print quality by Le, it is possible to improve the cost and productivity of the material.

The web tension control method for a rotary printing press according to the present invention is provided at the entrance side of the printing unit, has a drive unit independent of the drive system of the main machine main body, and has a function of performing web tension control. An infeed portion having a web provided upstream of the cutting device of the folder section, having a driving means independent of a drive system of the main machine body, and provided upstream of the folder section while pinching the web Since the rotary press is accelerated after the tensioning unit having the function of performing web tension control based on the detection signal of the tension detecting unit and the tension control unit starts tension control, the same effect as the above invention can be obtained. Can be.

[Brief description of the drawings]

FIG. 1 is an overall schematic configuration diagram showing a web tension control device installed in a commercial offset rotary printing press according to a first embodiment of the present invention.

FIG. 2 is a conceptual diagram illustrating functions of the web tension control device.

FIG. 3 is a conceptual diagram showing a main part of a web tension control device installed in a commercial offset rotary press according to a second embodiment of the present invention.

FIG. 4 is a schematic configuration diagram showing a main part of a web tension control device installed in a conventional general commercial web offset press.

FIG. 5 is a schematic configuration diagram illustrating a defect of the web tension control device in FIG. 4;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 paper feed unit 2 infeed unit 3 printing unit 4 cooling unit 5 web pass unit 6 folder unit 7 control unit 8 web 9 first nipping roller 10 motor 11 pretension roller 12 infeed roller 13 motor 14 tension pickup device 15 balance Weight roller 16 fulcrum shaft 17 balance weight roller arm 18 reel stand 19 main drive shaft 20 motor 21 air cylinder 22 web paper 23 stepless converter 24 printing device 25 triangular plate 26 lead-in roller 27 second nipping roller 30 drying unit 31 signature 32 Web tension detector 33, 43 Folder tension applying section 44 Folder tension applying mechanism 49 Forming roller

Claims (6)

[Claims] 1. An infeed unit which is provided at an entrance side of a printing unit, has driving means independent of a driving system of a main machine main body, and has a function of performing web tension control, and is provided upstream of a folding unit unit. A web tension detecting unit for detecting web tension, a driving unit provided upstream of the cutting device of the folding unit, independent of a driving system of the main machine main body, and the web tension while clamping the web. A web tension control device for a rotary printing press, comprising: a folder tension applying unit having a function of performing web tension control based on a detection signal from a detection unit. 2. The infeed unit is provided with an infeed roller for applying tension to a web fed to a printing unit, and the infeed roller includes a driving unit that is driven independently of a driving system of a printing press main body. 2. The web tension control device of a rotary printing press according to claim 1, wherein the web tension control device is configured to rotate via a web. 3. The folding machine tension applying section is provided with a pair of pretension rollers for sandwiching the web, and the pretension rollers are driven independently of the drive system of the folding machine body and at an arbitrary rotation speed. 2. The web tension control device of a rotary printing press according to claim 1, wherein the web tension control device is configured to rotate through a driving unit that performs rotation. 4. The web tension control device for a rotary printing press according to claim 1, wherein the folder tension applying unit is provided near a nip roller provided in the folder unit. 5. The rotary printing press according to claim 1, wherein the folder tension applying section is provided with a folder tension applying mechanism instead of a nipping roller provided in the folder section. Web tension control device. 6. An infeed unit provided at an entrance side of a printing unit, having a driving unit independent of a driving system of a main machine main body, and having a function of performing web tension control, and a cutting device of the folding unit unit. A function provided on the upstream side and having driving means independent of the drive system of the main machine main body, and performing web tension control based on a detection signal of a web tension detection unit provided upstream of the folding unit while holding the web. A web tension control method for a rotary printing press, characterized in that the web offset press accelerates after the tension control unit having the folding machine tension control unit starts tension control.