JP7312677B2 - WEB TENSION ADJUSTMENT APPARATUS AND METHOD AND PRINTING MACHINE - Google Patents

Description

The present invention relates to a web tension adjusting device and method for adjusting the tension of a web conveyed by a plurality of driving rollers, and a printing press to which the web tension adjusting device is applied.

For example, a newspaper offset rotary press consists of a feeder, a printer, a web path, and a folder. Before starting printing, a newspaper offset rotary printing press performs a paper threading operation in which the leading edge of a web drawn out from a roll of paper supported by a paper feeding device is guided through a printing device and a web path device to a folding machine. After the paper threading work is completed, tension adjustment work is performed to set the tension of the web passed from the paper feeding device to the folding machine to an appropriate value.

Techniques for adjusting the web tension are disclosed in, for example, the following patent documents. The printing press described in Patent Document 1 performs a tension applying operation in which, among the rollers provided on the web path, the rollers that affect the tension of the web are attached to the web, the printing cylinder is disengaged, and the tension of the web is increased. Further, the control method at the start of operation of a rotary printing press described in Patent Document 2 is to make the peripheral speed of the upstream drag slower than the peripheral speed of the downstream drag, and when the tension of the web between the upstream drag and the downstream drag reaches an appropriate value, the upstream drag is returned to the slow running speed.

JP 2008-105277 A Japanese Patent No. 3564409

In the above-described conventional printing press, the web tension is increased while the print cylinder is disengaged from the web. At this time, the upstream drag is set at a lower speed than the downstream drag to increase the web tension, and when the web tension reaches an appropriate value, the upstream drag is returned to the slow running speed. By the way, in a printing press, even when the printing cylinders are separated from the web, some of the printing cylinders are in contact with the web. Therefore, even if the web tension is adjusted between the upstream drag and the downstream drag, the web tension on the downstream side of the print cylinder may be lower than the proper value. In this state, when the printing cylinder is attached to the web, there is a problem that excessive stress acts on the web, which is not properly tensioned, and breaks the web.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a web tension adjusting device and method, and a printing press, which are intended to solve the above-described problems, and which enable the web tension to be adjusted appropriately and improve the workability of the web tension adjusting work.

A web tension adjusting device of the present invention for achieving the above-described object comprises an upstream driving roller and a downstream driving roller that are arranged at a predetermined interval in the web conveying direction and are capable of conveying the web, an intermediate driving roller that is arranged between the upstream driving roller and the downstream driving roller and is capable of conveying the web, an upstream tension detector that detects the tension of the web in an upstream section from the intermediate driving roller in the web conveying direction, and a downstream section from the intermediate driving roller to the downstream side in the web conveying direction. and a control device capable of adjusting the tension of the web by controlling the rotation speed of the upstream drive roller based on the detection results of the upstream tension detector and the downstream tension detector.

Therefore, since the web tension is adjusted by controlling the rotation speed of the upstream drive roller based on the web tension in the upstream section and the web tension in the downstream section with respect to the intermediate drive roller, even if there is an intermediate drive roller between the upstream section and the downstream section, the tension of the web in the upstream section and the web tension in the downstream section can be properly adjusted. As a result, it is possible to properly adjust the tension of the web and to improve the workability of the work for adjusting the tension of the web.

In the web tension adjusting device of the present invention, the control device adjusts the web tension in the downstream section to a preset downstream proper tension, and then adjusts the web tension in the upstream section to the preset upstream proper tension.

Therefore, after the web tension in the downstream section is adjusted to the downstream proper tension, the web tension in the upstream section is adjusted to the upstream proper tension. Therefore, when the upstream proper tension is adjusted, the web tension that has already been adjusted to the downstream proper tension does not fluctuate, and the web tension can be adjusted efficiently.

In the web tension adjusting device of the present invention, the control device makes the rotational speed of the upstream drive roller lower than the rotational speed of the downstream drive roller, and when the tension of the web in the downstream section reaches the proper downstream tension, controls the rotational speed of the upstream drive roller so that the proper downstream tension is maintained.

Therefore, since the rotational speed of the upstream drive roller is set lower than the rotational speed of the downstream drive roller, the tension of the web can be easily increased. When the tension of the web in the downstream section is adjusted to the proper tension on the downstream side, the rotational speed of the upstream drive roller is controlled so that the proper tension on the downstream side is maintained, so that the tension of the web can be adjusted efficiently.

In the web tension adjusting device of the present invention, when the tension of the web in the downstream section reaches a preset downstream proper low tension lower than the downstream proper tension, the control device changes the rotational speed of the upstream drive roller to adjust the tension to the proper tension.

Therefore, when the tension of the web in the downstream section reaches the appropriate low tension on the downstream side, the rotation speed of the upstream driving roller is changed to adjust the tension to the appropriate tension, so that the tension of the web is increased step by step, and breakage of the web due to a rapid increase in tension can be suppressed.

In the web tension adjusting device of the present invention, a presser roller is provided that pinches the web by coming into contact with at least one of the upstream drive roller and the downstream drive roller, and the control device moves the presser roller from the disengaged position to the applied position when the tension of the web in the downstream section reaches the appropriate low tension on the downstream side.

Therefore, when the tension of the web in the downstream section reaches the proper low tension on the downstream side, the pressure roller moves from the disengaged position to the applied position, so that the tension of the web increases while the web is nipped between the upstream drive roller, the downstream drive roller, and the respective pressure rollers, and the web is stably supported, thereby suppressing the breakage of the web.

In the web tension adjusting device of the present invention, a presser roller is provided that pinches the web by coming into contact with at least one of the upstream drive roller and the downstream drive roller, and the control device is characterized in that, after adjusting the tension of the web in the downstream section to the appropriate downstream tension, the intermediate drive roller in the spaced position is moved to the contact position, and then the presser roller is moved from the release position to the application position.

Therefore, after the tension of the web in the downstream section is adjusted to the proper tension on the downstream side, the intermediate drive roller at the separated position is moved to the contact position, and then the pressure roller is moved from the disengaged position to the on position. Therefore, when the web is nipped by the upstream drive roller, the downstream drive roller, and the respective pressure rollers, the tension of the web is already adjusted to the proper downstream tension, which suppresses an instantaneous increase in the tension on the web, thereby suppressing breakage of the web.

In the web tension adjusting device of the present invention, the control device adjusts the web tension in the upstream section to a preset upstream tension for downstream tension adjustment, and then, when the web tension in the downstream section reaches a preset downstream proper tension, adjusts the web tension in the upstream section to the preset upstream proper tension.

Therefore, after the web tension in the upstream section is adjusted to the upstream tension for downstream tension adjustment, when the web tension in the downstream section reaches the preset downstream proper tension, the web tension in the upstream section is adjusted to the upstream proper tension, so that the web tension can be increased early to adjust the web tension to the upstream proper tension.

In the web tension adjusting device of the present invention, the control device makes the rotational speed of the upstream drive roller lower than the rotational speed of the downstream drive roller, and when the web tension in the downstream section reaches the proper downstream tension, controls the rotational speed of the upstream drive roller so that the current tension of the web is maintained.

Therefore, when the rotational speed of the upstream drive roller is set lower than the rotational speed of the downstream drive roller and the tension of the web in the downstream section reaches the appropriate downstream tension, the rotational speed of the upstream drive roller is controlled so that the current web tension is maintained, so that the web tension can be efficiently adjusted.

In the web tension adjusting device of the present invention, the control device adjusts the web tension in the downstream section to the proper downstream tension, then moves the intermediate drive roller in the spaced position to the contact position, and then adjusts the web tension in the upstream section to the proper upstream tension.

Therefore, after the tension of the web in the downstream section is adjusted to the proper tension on the downstream side, the intermediate driving roller at the separated position is moved to the contacting position, and then the tension of the web in the upstream section is adjusted to the proper tension on the upstream side. Therefore, the intermediate driving roller is moved to the contacting position in a state in which the tension of the web is adjusted to the proper tension on the downstream side, and breakage of the web can be suppressed.

In the web tension adjusting device of the present invention, the control device starts the driving rotation of the downstream driving roller in a state where the driving rotation of the upstream driving roller is stopped, and when the tension of the web in the downstream section increases, the driving rotation of the upstream driving roller is started.

Therefore, the downstream drive roller starts to rotate while the upstream drive roller stops rotating, and when the tension of the web in the downstream section increases, the upstream drive roller starts to rotate, so that slack in the web can be quickly eliminated.

In the web tension adjusting device of the present invention, the intermediate driving rollers are a pair of blanket cylinders in the printing apparatus, and are movable between a separated position where a gap is secured between them and the pair of blanket cylinders and a contact position where there is no gap between them and the pair of blanket cylinders, and when the pair of blanket cylinders are in the separated position, at least one of the pair of blanket cylinders contacts the web.

Therefore, even if at least one of the blanket cylinders is in contact with the web, the web tension in the upstream section and the web tension in the downstream section can be properly adjusted. As a result, it is possible to improve the workability of the web tension adjustment work.

In the web tension adjusting device of the present invention, a path length changing device capable of changing the path length of the web is provided between the upstream drive roller and the downstream drive roller, and the control device is characterized in that the web tension is adjusted by controlling the path length changing device based on the detection result of the upstream tension detector or the downstream tension detector.

Therefore, since the web tension is adjusted by controlling the path length changing device based on the detection result of the upstream tension detector or the downstream tension detector, the web tension can be quickly adjusted by combining with the method of controlling the rotational speed of the upstream drive roller or the downstream drive roller.

In the web tension adjustment device of the present invention, a plurality of web tension adjustment sections between the upstream drive roller and the downstream drive roller are provided along the web transport direction, and the control device is characterized by adjusting the web tension from the web tension adjustment section on the downstream side in the web transport direction among the plurality of web tension adjustment sections.

Therefore, since the web tension is adjusted from the downstream web tension adjustment section in the web transport direction among the plurality of web tension adjustment sections, when adjusting the web tension in the upstream tension adjustment section, the web tension in the already adjusted downstream tension adjustment section does not fluctuate, and the web tension can be adjusted efficiently.

In the web tension adjustment device of the present invention, a plurality of web tension adjustment sections between the upstream drive roller and the downstream drive roller are provided along the web conveying direction, and the control device is characterized by adjusting the web tension from the upstream web tension adjustment section in the web conveyance direction among the plurality of web tension adjustment sections.

Therefore, since the web tension is adjusted from the upstream web tension adjustment section in the web transport direction among the plurality of web tension adjustment sections, when adjusting the web tension in the downstream tension adjustment section, the web tension in the already adjusted upstream tension adjustment section does not fluctuate, and the web tension can be adjusted efficiently.

Further, the web tension adjustment method of the present invention includes an upstream driving roller and a downstream driving roller that are arranged at a predetermined interval in a web conveying direction and are capable of conveying the web, and an intermediate driving roller that is arranged between the upstream driving roller and the downstream driving roller and is capable of conveying the web. and adjusting the tension of the web by controlling the rotation speed of the upstream driving roller based on the tension of the web in the upstream section and the tension of the web in the downstream section.

Therefore, even if there is an intermediate drive roller between the upstream section and the downstream section, the web tension in the upstream section and the web tension in the downstream section can be properly tension-adjusted. As a result, it is possible to properly adjust the tension of the web and to improve the workability of the work for adjusting the tension of the web.

Further, the printing press of the present invention is characterized by comprising a paper feeding device for supplying a web, a printing device for printing on the web fed from the paper feeding device, a folding device for longitudinally folding the web printed by the printing device and then cutting the web to form a predetermined signature, and a tension adjusting device for the web.

Therefore, even if there is an intermediate drive roller between the upstream section and the downstream section, the web tension in the upstream section and the web tension in the downstream section can be properly tension-adjusted. As a result, it is possible to properly adjust the tension of the web and to improve the workability of the work for adjusting the tension of the web.

In the printing machine of the present invention, the paper feeding device has a plurality of paper feeding units, the printing device has a plurality of printing devices, and the folding device vertically folds the plurality of webs printed by the printing devices and then cuts them to form a predetermined signature. When the tension of the webs in all the downstream sections of the plurality of web transport paths is adjusted to a predetermined downstream proper tension, the control device shifts the intermediate drive roller from the spaced position to the contact position. characterized by movement.

Therefore, when the tension of all the webs is adjusted to the proper tension on the upstream side, the intermediate driving rollers in the separated position are moved to the contacting position, so that the intermediate driving rollers come into contact with all the webs at the same time, and breakage of the webs can be suppressed.

According to the web tension adjusting apparatus and method and the printing press of the present invention, it is possible to appropriately adjust the web tension and improve the workability of the web tension adjusting work.

FIG. 1 is a schematic configuration diagram showing a web tension adjusting device according to the present embodiment. FIG. 2 is a schematic diagram showing the throw-on state of the printing unit. FIG. 3 is a schematic diagram showing the unthrown state of the printing unit. FIG. 4-1 is a schematic diagram showing the content of web tension adjustment work. FIG. 4-2 is a schematic diagram showing a modified example of web tension adjustment work. FIG. 5 is a flow chart showing a web tension adjustment operation in the printing unit. FIG. 6 is a flow chart showing a first modification of the web tension adjustment operation in the printing unit. FIG. 7 is a flow chart showing a second modification of the web tension adjustment operation in the printing unit. FIG. 8 is a schematic configuration diagram showing a modification of the web tension adjusting device of the present embodiment. FIG. 9 is a flow chart showing a web tension adjustment operation in the web pass unit. FIG. 10 is a timing chart showing the web tension adjustment work. FIG. 11 is a timing chart showing a first modification of the web tension adjustment work. FIG. 12 is a timing chart showing a second modification of the web tension adjustment work. FIG. 13 is a timing chart showing a third modification of the web tension adjustment work. FIG. 14 is a flow chart representing a printing operation. FIG. 15 is a timing chart showing a modification of the web tension adjustment work. FIG. 16 is a flow chart showing a modification of the printing work. FIG. 17 is a schematic configuration diagram showing a newspaper offset rotary printing press. FIG. 18 is a schematic configuration diagram showing a printing unit in an offset rotary printing press for newspapers.

Preferred embodiments of a web tension adjusting apparatus and method and a printing press according to the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the present invention is not limited by this embodiment, and when there are a plurality of embodiments, it also includes a combination of each embodiment.

FIG. 17 is a schematic configuration diagram showing a newspaper offset rotary printing press.

As shown in FIG. 17, the printing press of this embodiment is a newspaper offset rotary printing press 10, comprising a paper feeding device R, an infeed device I, a printing device U, a web path device D, and a folding machine F. The paper feeding device R has a plurality of (seven in this embodiment) paper feeding units R1 to R7, the infeed device I has a plurality of (seven in this embodiment) infeed units I1 to I7, the printing device U has a plurality of (six in this embodiment) printing units U1 to U6, the web path device D has a plurality of (two in this embodiment) web path units D1 and D2, and the folding machine F has a plurality of (two in this embodiment) table) folding units F1 and F2.

Although six printing units U1 to U6 have been described, each printing unit U1 to U6 is capable of four-color printing, and can also be divided into upper and lower units and used as 12 printing units U11, U12, U21 . . . U61, U62 capable of two-color printing. Also, although the two folding units F1 and F2 are arranged vertically, they are actually the operating side folding unit F1 and the drive side folding unit F2 arranged side by side in the direction orthogonal to the plane of the drawing. Furthermore, although the printing apparatus U has been described from two parts, it is only described as being divided into two parts for functional reasons, and in reality it is one apparatus.

In the paper feeding device R, the paper feeding units R1 to R7 have substantially the same configuration, and have a holding arm for holding three paper rolls on which the web W is wound in a roll. In the infeed device I, the infeed units I1 to I7 have substantially the same configuration, and adjust the tension of the web W sent to each of the printing units U1 to U6 of the printing device U, thereby stably maintaining the tension of the web W traveling through the printing device U at an appropriate value. The tension of the web W from the sheet feeding device R to the infeed device I is performed by a brake device (not shown) provided in the sheet feeding units R1 to R7.

In the printing apparatus U, the printing units U1 to U6 are multi-color printing units capable of performing two-sided four-color printing. However, each of the printing units U1 to U6 can be divided into upper and lower printing units U11 to U62 capable of double-sided two-color printing. The printing units U11 to U62 have substantially the same configuration and have ink supply devices, plate cylinders, blanket cylinders, and the like. In the printing units U1 to U6, the peripheral length (diameter) of the plate cylinder and the peripheral length (diameter) of the blanket cylinder are set to be the same. Here, in the printing units U1 to U6, the peripheral length (diameter) of the plate cylinder and the blanket cylinder are set to be the same as the peripheral length (diameter) of the printing cylinder, but the peripheral length (diameter) of the printing cylinder may be 1/2 of the peripheral length (diameter) of the blanket cylinder.

In the web path device D, the web path unit D1 is provided for the printing units U1-U3, and the web path unit D2 is provided for the printing units U4-U6. The web pass units D1 and D2 have substantially the same configuration, and include a slitter that cuts the web W in the longitudinal direction (conveying direction of the web W) at the center of the width direction, a turn bar that sets the conveying route of the longitudinally cut web W, a compensator (route length changing device) that can change the route length of the web W, and the like.

Each web W printed by the printing units U1 to U3 is longitudinally cut by a slitter in a web pass unit D1, the conveying route is changed by a turn bar, and the route length is changed by a compensator, and then superimposed in a predetermined order. Each web W printed by the printing units U4 to U6 is longitudinally cut by a slitter in a web pass unit D2, the conveying path is changed by a turn bar, and the path length is changed by a compensator, and then superimposed in a predetermined order.

In the folding machine F, two folding units F1 and F2 are arranged on the operating side and the driving side. When a plurality of webs W1 are superimposed and introduced from the web pass unit D1, the folding unit F1 vertically folds the web W1, horizontally cuts it to a predetermined length, horizontally folds it to form a signature, and discharges it as a newspaper. When a plurality of webs W2 are superimposed and introduced from the web path unit D2, the folding unit F2 vertically folds the webs W2, horizontally cuts them to a predetermined length, horizontally folds them to form signatures, and discharges them as newspapers.

Here, the printing unit U1 in the printing apparatus U will be described in detail. FIG. 18 is a schematic configuration diagram showing a printing unit in an offset rotary printing press for newspapers.

The printing unit U1, as shown in FIG. 18, is an H-shaped tower unit so as to enable four-color printing. The printing unit U1 is configured by arranging four stacks 21, 22, 23, and 24 for black, indigo, magenta, and yellow along the conveying direction of the web W (the direction from bottom to top in FIG. 18), and the stacks 21, 22, 23, and 24 each have a symmetrical roller arrangement.

The stacks 21, 22, 23, and 24 are laterally opposed to each other, and the blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, and 34b can be in contact with each other across the conveying path of the web W. 3a, 43b, 44a and 44b face each other. The stacks 21, 22, 23, 24 are provided with ink feeders 51a, 51b, 52a, 52b, 53a, 53b, 54a, 54b for the plate cylinders 41a, 41b, 42a, 42b, 43a, 43b, 44a, 44b. Dampening devices 61a, 61b, 62a, 62b, 63a, 63b, 64a and 64b are provided for the plate cylinders 41a, 41b, 42a, 42b, 43a, 43b, 44a and 44b.

In the newspaper offset rotary printing press 10 of the present embodiment configured as described above, there is a work of adjusting the tension of the web W as a preparatory work before starting the printing operation. The newspaper offset rotary printing press 10 is provided with a plurality of rotatable drive rollers on the transport path of the web W, and a tension detector for indicating the tension of the web W in the area between the plurality of drive rollers. Therefore, the tension of the web W is adjusted by increasing or decreasing the rotational speeds of the plurality of drive rollers based on the detection result of the tension detector.

FIG. 1 is a schematic configuration diagram showing a web tension adjusting device according to the present embodiment.

As shown in FIG. 1, the paper feeding device R has a holding arm 101 that holds a plurality of (for example, three) paper rolls WR. The web W drawn out from the paper roll WR is sent to the infeed device I via a guide roller 102, a floating roller 103, a guide roller 104, a tension pickup roller 105, and a guide roller . The holding arm 101 is provided with a brake device 107 that brakes the web W unwound from the paper roll WR.

The infeed device I receives the web W supplied from the paper feeding device R and feeds it to the printing device U via the guide roller 108 , the infeed drag roller 109 , the paper pressure roller 110 and the tension pickup roller 111 . The in-feed drag roller 109 can be driven and rotated by a drive motor 112 .

The printer U has the blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, and 34b and the plate cylinders 41a, 41b, 42a, 42b, 43a, 43b, 44a, and 44b, and performs double-sided printing on the web W supplied from the infeed device I, as described above. The blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, 34b and the plate cylinders 41a, 41b, 42a, 42b, 43a, 43b, 44a, 44b can be independently driven and rotated by drive motors 113, 114, 115, 116. The printed web W is sent to the web path device D via the tension pickup roller 117 , exit drag roller 118 , paper pressure roller 119 and guide roller 120 . The outlet drag roller 118 can be driven and rotated by a drive motor 121 .

The web path device D cuts the web W supplied from the printing device U at the center in the width direction by the slitter knife 122 and the slitter drag roller 123, and the turn bar changes the conveying path and the compensator changes the path length. The slitter drag roller 123 can be driven and rotated by a drive motor 124 . After that, the web W is sent to the folding machine F via the intermediate drag rollers 125 and 126, the paper pressure rollers 127 and 128, the tension pickup rollers 129 and 130, the triangular plate drag roller 131 and the paper pressure roller 132. The intermediate drag rollers 125 and 126 can be driven to rotate by a drive motor 133 , and the triangular plate drag roller 131 can be driven to rotate by a drive motor 134 . Note that the paper pressing rollers 127 and 128 may not be provided for the intermediate drag rollers 125 and 126 .

The control device 140 can adjust the delivery speed of the web W from the paper roll WR by controlling the brake device 107 . Further, the control device 140 controls the drive motors 112, 113, 114, 115, 116, 121, 124, 133, 134 to control the infeed drag roller 109, the blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, 34b, the plate cylinders 41a, 41b, 42a, 42b, 43a, 43b, 44a, 44b, outlet drag roller 118, slitter drag roller 123, intermediate drag rollers 125, 126, triangular plate drag roller 131 can be controlled. Furthermore, the controller 140 receives detection values from the tension pickup rollers 105 , 111 , 117 , 129 and 130 .

By the way, during the printing operation of the newspaper offset rotary press 10, the printing apparatus U is in a throw-in state in which the outer peripheral surfaces of the blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, and 34b are in contact with the front and rear surfaces of the web W. On the other hand, during the tension adjustment operation in the newspaper offset rotary printing press 10, the printing device U is in a state where the outer peripheral surfaces of the blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, and 34b are separated from the front and back surfaces of the web W. However, the outer peripheral surfaces of some of the blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, and 34b are in contact with the front and back surfaces of the web W during this tension adjustment operation.

FIG. 2 is a schematic diagram showing a throw-on state of the printing unit, and FIG. 3 is a schematic diagram showing a throw-off state of the printing unit.

As shown in FIG. 2, the outer peripheral surfaces of the blanket cylinders 31a, 32a, 33a, and 34a and the outer peripheral surfaces of the blanket cylinders 31b, 32b, 33b, and 34b are in contact with the web W therebetween when the printing unit U1 is thrown on. The blanket cylinders 31a, 32a, 33a, 34a and the blanket cylinders 31b, 32b, 33b, 34b are arranged with a predetermined distance in the vertical direction, and in the throw-in state of the printing unit U1, the web W is wrapped around the outer peripheral surfaces of the blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, 34b at a predetermined angle.

On the other hand, as shown in FIG. 3, in the unthrown state of the printing unit U1, the outer peripheral surfaces of the blanket cylinders 31a, 32a, 33a, and 34a are separated from the outer peripheral surfaces of the blanket cylinders 31b, 32b, 33b, and 34b with the web W therebetween. At this time, the web W in the printing unit U1 is straight in the vertical direction. However, the web W is conveyed between the blanket cylinders 31a and 31b from the infeed drag roller 109 and the paper pressure roller 110 via the tension pickup roller 111. As shown in FIG. Here, the tension pickup roller 111 and the blanket cylinders 31a and 31b are arranged with a horizontal shift. Therefore, when the web W is transported from the tension pickup roller 111 between the blanket cylinders 31a and 31b, the web W is wrapped around the outer peripheral surface of the blanket cylinder 31b at a predetermined angle. Also, when the web W passes through the printing unit U1, it contacts some of the blanket cylinders 32a, 33b, and 34a.

When the work for adjusting the tension of the web W is carried out in the offset rotary printing press 10 for newspapers, the tension of the web W is adjusted in the section where the printing unit U1 exists, with the section between the infeed drag roller 109 and the exit drag roller 118 set as one section in the unthrown state. However, as described above, the printing unit U1 is located between the infeed drag roller 109 and the exit drag roller 118, and some of the blanket cylinders 31b, 32a, 33b, and 34a are in contact with the web W. Therefore, the tension of the web W differs between the upstream side and the downstream side of the printing unit U1, making it difficult to adjust the tension of the web W to an appropriate value. After the printing plates are mounted on the plate cylinders 41a, 41b, 42a, 42b, 43a, 43b, 44a, and 44b, the phases of the plate cylinders 41a, 41b, 42a, 42b, 43a, 43b, 44a, and 44b and the blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, and 34b must be adjusted. At this time, forward rotation and reverse rotation are performed, and the web W is loosened or pulled, so that the tension of the web W is in various states.

Therefore, in this embodiment, the tension of the web W is adjusted to an appropriate value by controlling the rotational speeds of the infeed drag roller 109 and the exit drag roller 118 based on the tension of the web W on the upstream side of the printing unit U1 and the tension of the web W on the downstream side of the printing unit U1.

The web tension adjusting device of the present embodiment includes an upstream drive roller and a downstream drive roller that are arranged at a predetermined interval in the web W conveyance direction and can convey the web W, an intermediate drive roller that is arranged between the upstream drive roller and the downstream drive roller and can convey the web W, an upstream tension detector that detects the tension of the web W in the upstream section in the conveyance direction of the web W from the intermediate drive roller, and a downstream side that detects the tension of the web W in the downstream section in the conveyance direction of the web W from the intermediate drive roller. A tension detector and a control device capable of adjusting the rotational speed of the upstream driving roller based on the detection results of the upstream tension detector and the downstream tension detector are provided.

Hereinafter, the web tension adjusting device of the present embodiment will be described in detail. First, the section in which the printing unit U1 is arranged will be described by applying it to the web tension adjustment section by the web tension adjustment device of the present embodiment. In this case, as shown in FIG. 1, the upstream drive roller corresponds to the infeed drag roller 109, the downstream drive roller corresponds to the outlet drag roller 118, the intermediate drive rollers correspond to the blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, and 34b, the upstream tension detector corresponds to the tension pickup roller 111, the downstream tension detector corresponds to the tension pickup roller 117, and the controller corresponds to the controller 140. The upstream section is the section between the infeed drag roller 109 and the blanket cylinders 31 a and 31 b , and the downstream section is the section between the blanket cylinders 34 a and 34 b and the outlet drag roller 118 . However, a plurality of rollers other than the blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, 34b, such as guide rollers and drive rollers, may be arranged in the upstream section and the downstream section.

FIG. 4-1 is a schematic diagram showing the content of the web tension adjustment work, and FIG. 5 is a flow chart showing the web tension adjustment work in the printing unit.

As shown in FIGS. 1 and 4-1, in the tension adjustment work of the web W, the control by the control device 140 includes (1) paper tension control, (2) low tension application control, (3) paper pressure control, (4) proper tension application control, (5) slow operation control, and (6) upstream tension control.

(1) Paper tension control is control that pulls the downstream side of the web W after threading to eliminate slack, and the target tension in the downstream section is Td1 (for example, a value greater than 0). When the rotational speed of the downstream drive roller (exit drag roller 118) is 100%, the speed ratio of the upstream drive roller (infeed drag roller 109) is, for example, 0%, and the speed ratio of the printing units (blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, 34b) is, for example, 0%. At this time, the paper pressing rollers 110 and 119 of the infeed drag roller 109 and the exit drag roller 118 are in the released state.

(2) Low-tension application control is control for applying a preset downstream-side appropriate low-tension to the web W in the downstream section after the paper tension control, and the target tension is Td2 higher than Td1. The speed ratio of the upstream drive roller (infeed drag roller 109) is, for example, 99%, and the speed ratio of the printing units (blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, 34b) is, for example, 100%.

(3) Paper holding control is control to pinch and hold the web W between the infeed drag roller 109 and the paper holding roller 110 and the exit drag roller 118 and the paper holding roller 119 after the low tension application control. That is, the paper pressing rollers 110 and 119 are moved from the disengaged position to the applied position. The target tension in the downstream section (appropriate low tension Td2 on the downstream side), the speed ratio of the upstream drive roller (infeed drag roller 109), and the speed ratio of the printing units (blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, 34b) are not changed.

(4) Appropriate tension application control is control for applying a preset downstream appropriate tension to the web W in the downstream section after the paper holding control, and the target tension is Td3 higher than Td2. The speed ratio of the upstream drive roller (infeed drag roller 109) is, for example, 98%, and the speed ratio of the printing units (blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, 34b) is, for example, 100%.

(5) Slow operation control is control for maintaining the tension of the web W in the downstream section at the downstream proper tension after the proper tension application control, and the target tension is Td3. The speed ratio of the upstream drive roller (infeed drag roller 109) is N%, and this speed ratio N% is feedback-controlled. Also, the speed ratio of the printing units (blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, 34b) is not changed. At this time, the paper pressing rollers 110 and 119 of the infeed drag roller 109 and the exit drag roller 118 are in the worn state.

(6) The upstream tension control is control that applies a preset upstream appropriate tension to the web W in the upstream section after the slow operation control, and the target tension is Tua higher than Td3. The speed ratio of the upstream drive roller (infeed drag roller 109) is Na% lower than 98%.

A tension adjusting operation of the web W by the web tension adjusting apparatus of the present embodiment will be specifically described. As shown in FIGS. 3 and 5, when the tension adjustment work of the web W is started, the printing unit U1 is in a state where the outer peripheral surfaces of the blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, and 34b are separated from the front and back sides of the web W.

In step S11, control device 140 determines whether or not the paper threading operation is completed. Here, if it is determined (No) that the paper threading operation has not been completed, this state is maintained. On the other hand, if it is determined that the paper threading operation is completed (Yes), in step S12, the control device 140 determines whether or not the cylinder phase alignment of the printing unit U1 is completed. In the cylinder phasing operation, the plate cylinders 41a, 41b, 42a, 42b, 43a, 43b, 44a, 44b are rotated slowly, rapidly, forwardly, or reversely to align the phases. Therefore, the web W between the upper and lower blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, and 34b rotating in synchronization with the plate cylinders 41a, 41b, 42a, 42b, 43a, 43b, 44a, and 44b may be loosened or stretched in various ways. Here, if it is determined (No) that the cylinder phase alignment of the printing unit U1 has not been completed, this state is maintained. On the other hand, if it is determined (Yes) that the cylinder phase adjustment of the printing unit U1 has been completed, the paper tensioning operation is started after step S13.

In step S14, the control device 140 drives and rotates the downstream drive roller (outlet drag roller 118) to perform paper tension control. Then, slack in the web W is eliminated in the section between the upstream drive roller (infeed drag roller 109) and the downstream drive roller (outlet drag roller 118), and tension is generated in the web W. In step S15, the control device 140 determines whether or not the tension Td of the web W in the downstream section has become equal to or greater than the target tension Td1 (eg, 0). The tension Td of the web W uses the result of detection by the tension pickup roller 117 . Here, if it is determined that the tension Td of the web W is smaller than the target tension Td1 (No), this state is maintained. On the other hand, when it is determined (Yes) that the tension Td of the web W is equal to or higher than the target tension Td1, in step S16, the printing unit U1 (blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, 34b) and the upstream drive roller (infeed drag roller 109) are driven to rotate, and the upstream drive roller (infeed drag roller 109) is adjusted to perform low tension application control. Then, the tension of the web W increases in the section between the upstream drive roller (infeed drag roller 109) and the downstream drive roller (exit drag roller 118).

In step S17, the control device 140 determines whether the tension Td of the web W in the downstream section has become equal to or greater than the downstream appropriate low tension Td2. Here, if it is determined (No) that the tension Td of the web W is smaller than the downstream appropriate low tension Td2, this state is maintained. On the other hand, if it is determined (Yes) that the tension Td of the web W is equal to or higher than the downstream proper low tension Td2, then in step S18, the paper pressure rollers 110 and 119 are moved from the release position to the arrival position. In this case, only the paper pressing roller 110 may be moved from the disengaged position to the applied position. Subsequently, in step S19, the control device 140 reduces the rotational speed of the upstream drive roller (infeed drag roller 109) to perform proper tension application control. That is, since the rotation speed of the upstream drive roller (infeed drag roller 109) is slower than the rotation speed of the downstream drive roller (outlet drag roller 118), the tension of the web W increases in the section between the upstream drive roller (infeed drag roller 109) and the downstream drive roller (outlet drag roller 118).

However, in the proper tension application control in step S19, if the downstream proper tension Td3 is lower than the downstream proper low tension Td2, the rotational speed of the upstream driving roller (infeed drag roller 109) may be increased.

In step S20, the control device 140 determines whether or not the tension Td of the web W in the downstream section has reached the downstream proper tension Td3. Here, if it is determined (No) that the tension Td of the web W is lower than the downstream side proper tension Td3, this state is maintained. On the other hand, if it is determined (Yes) that the tension Td of the web W is the same as the proper tension Td3 on the downstream side, in step S21, the slow operation control is performed to maintain the tension Td of the web W in the downstream section at the proper tension Td3 on the downstream side. By performing the slow operation control, the paper-pasting operation is completed in step S22.

As shown in FIGS. 4-1 and 5, in step S23, throwing-in is performed in the printing unit U1 so that the outer peripheral surfaces of the blanket cylinders 31a, 32a, 33a, and 34a are brought into contact with the outer peripheral surfaces of the blanket cylinders 31b, 32b, 33b, and 34b with the web W interposed therebetween. In the newspaper offset rotary printing press 10, each of the paper feeding device R, the infeed device I, the printing device U, and the web path device D has a plurality of units. Therefore, there are multiple web transport paths. Therefore, when there are a plurality of web transport paths, it is desirable to throw-on the blanket cylinders 31a, 32a, 33a, and 34a on all the web transport paths when the tension Td of the web W reaches the proper tension Td3 on the downstream side and the paper stretching operation is completed on all the web transport paths.

Thereafter, in step S24, the control device 140 further reduces the rotational speed of the upstream drive roller (infeed drag roller 109) to perform upstream tension control. That is, since the rotation speed of the upstream drive roller (infeed drag roller 109) is further reduced with respect to the rotation speed of the downstream drive roller (outlet drag roller 118), the tension of the web W further increases in the section between the upstream drive roller (infeed drag roller 109) and the downstream drive roller (outlet drag roller 118). The web tension adjusting device of the present embodiment performs the above control, but is not limited to this. For example, the process of step S23 and the process of step S26 may be performed in reverse, or may be performed simultaneously. In addition, when there are a plurality of webs W, the throw-in operation is performed after confirming that the paper-stretching operation of the other units has been completed.

In step S25, the control device 140 determines whether or not the tension Tu of the web W in the upstream section has become equal to or greater than the upstream proper tension Tua. The tension Tu of the web W uses the result of detection by the tension pickup roller 111 . Here, when it is determined (No) that the tension Tu of the web W is smaller than the upstream-side appropriate tension Tua, this state is maintained. On the other hand, if it is determined (Yes) that the tension Tu of the web W is equal to or greater than the appropriate upstream tension Tua, the upstream tension control is completed by maintaining the tension of the web W in the upstream section at the upstream appropriate tension in step S26. After the printing unit U1 is accelerated in step S27, printing is started in step S28.

The tension adjustment work of the web W by the web tension adjustment device of the present embodiment is not limited to the method described above. FIG. 4-2 is a schematic diagram showing a modification of the web tension adjustment work content, FIG. 6 is a flowchart showing a first modification of the web tension adjustment work in the printing unit, and FIG. 7 is a flowchart showing a second modification of the web tension adjustment work in the printing unit. Steps having functions similar to those of the above-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIGS. 1 and 4-2, in the tension adjustment work of the web W, the control by the control device 140 includes (1) paper tension control, (2) low tension application control, (3) paper pressure control, (4) proper tension application control, (5) slow operation control, and (6) upstream tension control.

(1) Paper tension control is control for pulling the downstream side of the web W after threading to eliminate slack, and the target tension for the upstream section is Tu1 (for example, a value greater than 0).
(2) Low-tension application control is control for applying a preset downstream-side appropriate low tension (upstream-side tension for adjusting downstream-side tension) to the web W in the upstream section after the paper tension control, and the target tension is Tu2, which is higher than Tu1.
(3) Paper holding control is control to pinch and hold the web W between the infeed drag roller 109 and the paper holding roller 110 and the exit drag roller 118 and the paper holding roller 119 after the low tension application control. That is, the paper pressing rollers 110 and 119 are moved from the disengaged position to the applied position. This is the target tension of the upstream section (upstream tension Tu2 for downstream tension adjustment).
(4) Appropriate tension application control is control for applying a preset downstream appropriate tension to the web W in the downstream section after the paper holding control, and the target tension is Td3 higher than Tu2.
(5) Slow operation control is control for maintaining the tension of the web W in the downstream section at the downstream proper tension after the proper tension application control, and the target tension is Td3.
(6) The upstream tension control is control that applies a preset upstream appropriate tension to the web W in the upstream section after the slow operation control, and the target tension is Tua higher than Td3.

A first modified example of the tension adjusting operation of the web W by the web tension adjusting apparatus of the present embodiment will be specifically described.

As shown in FIGS. 3 and 6, in step S11, control device 140 determines whether or not the paper threading operation is completed. Here, if it is determined that the paper threading operation is completed (Yes), in step S12, the control device 140 determines whether or not the cylinder phase matching of the printing units is completed. Here, if it is determined that the cylinder phase adjustment of the printing unit has been completed (Yes), the paper tensioning operation is started from step S13 onward.

In step S14, the control device 140 drives and rotates the downstream drive roller (outlet drag roller 118) to perform paper tension control. Then, the slackness of the web W is eliminated in the upstream section and the downstream section, and tension is generated in the web W. In step S15A, the control device 140 determines whether or not the tension Tu of the web W in the upstream section has reached or exceeded the target tension Tu1 (for example, 0). Here, when it is determined (Yes) that the tension Tu of the web W is equal to or higher than the target tension Tu1, in step S16, the printing unit U1 (blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, 34b) and the upstream drive roller (infeed drag roller 109) are driven to rotate, and the upstream drive roller (infeed drag roller 109) is adjusted to perform low tension application control. Then, the tension of the web W increases in the section between the upstream drive roller (infeed drag roller 109) and the downstream drive roller (exit drag roller 118).

In step S17A, the control device 140 determines whether or not the tension Tu of the web W in the upstream section has become equal to or greater than the upstream tension Tu2 for downstream tension adjustment. Here, if it is determined (Yes) that the tension Tu of the web W is equal to or higher than the upstream tension Tu2 for downstream tension adjustment, then in step S18, the paper pressing rollers 110 and 119 are moved from the release position to the arrival position. Subsequently, in step S19, the control device 140 reduces the rotational speed of the upstream drive roller (infeed drag roller 109) to perform proper tension application control.

In step S20A, the control device 140 determines whether the tension Td of the web W in the downstream section has become equal to or greater than the appropriate downstream tension Td3. Here, if it is determined (No) that the tension Td of the web W is lower than the downstream side proper tension Td3, this state is maintained. On the other hand, when it is determined (Yes) that the tension Td of the web W is equal to or greater than the proper tension Td3 on the downstream side, in step S21, slow operation control is performed to maintain the tension Tu of the web W at the current tension in the upstream section. By performing the slow operation control, the paper-pasting operation is completed in step S22.

As shown in FIGS. 4-2 and 6, in step S23, throwing-in is performed in the printing unit U1 so that the outer peripheral surfaces of the blanket cylinders 31a, 32a, 33a, and 34a come into contact with the outer peripheral surfaces of the blanket cylinders 31b, 32b, 33b, and 34b with the web W interposed therebetween. Thereafter, in step S24, the control device 140 further reduces the rotational speed of the upstream drive roller (infeed drag roller 109) to perform upstream tension control. In step S25, the control device 140 determines whether the tension Tu of the web W in the upstream section has become equal to or greater than the upstream proper tension Tua. Here, if it is determined (Yes) that the tension Td of the web W is equal to or greater than the appropriate upstream tension Tua, the upstream tension control is completed by maintaining the tension of the web W in the upstream section at the upstream appropriate tension in step S26. After the printing unit U1 is accelerated in step S27, printing is started in step S28.

Further, a second modified example of the tension adjusting operation of the web W by the web tension adjusting apparatus of the present embodiment will be specifically described.

As shown in FIGS. 3 and 7, in step S11, control device 140 determines whether or not the paper threading operation is completed. Here, if it is determined (No) that the paper threading operation has not been completed, this state is maintained. On the other hand, if it is determined that the paper threading operation is completed (Yes), in step S12, the control device 140 determines whether or not the cylinder phase alignment of the printing unit U1 is completed. Here, if it is determined (No) that the cylinder phase alignment of the printing unit U1 has not been completed, this state is maintained. On the other hand, if it is determined (Yes) that the cylinder phase adjustment of the printing unit U1 has been completed, the paper tensioning operation is started after step S13.

In step S14, the control device 140 drives and rotates the downstream drive roller (outlet drag roller 118) to perform paper tension control. Then, slack in the web W is eliminated in the section between the upstream drive roller (infeed drag roller 109) and the downstream drive roller (outlet drag roller 118), and tension is generated in the web W. In step S15, the control device 140 determines whether or not the tension Td of the web W in the downstream section has become equal to or greater than the target tension Td1 (eg, 0). Here, if it is determined that the tension Td of the web W is smaller than the target tension Td1 (No), this state is maintained. On the other hand, when it is determined (Yes) that the tension Td of the web W is equal to or higher than the target tension Td1, in step S16, the printing unit U1 (blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, 34b) and the upstream drive roller (infeed drag roller 109) are driven to rotate, and the upstream drive roller (infeed drag roller 109) is adjusted to perform low tension application control. Then, the tension of the web W increases in the section between the upstream drive roller (infeed drag roller 109) and the downstream drive roller (exit drag roller 118).

In step S17, the control device 140 determines whether the tension Td of the web W in the downstream section has become equal to or greater than the downstream appropriate low tension Td2. Here, if it is determined (No) that the tension Td of the web W is smaller than the downstream appropriate low tension Td2, this state is maintained. On the other hand, when it is determined (Yes) that the tension Td of the web W is equal to or higher than the downstream proper low tension Td2, in step S19, the control device 140 reduces the rotational speed of the upstream drive roller (infeed drag roller 109) to perform proper tension application control. That is, since the rotation speed of the upstream drive roller (infeed drag roller 109) is slower than the rotation speed of the downstream drive roller (outlet drag roller 118), the tension of the web W increases in the section between the upstream drive roller (infeed drag roller 109) and the downstream drive roller (outlet drag roller 118).

In step S20, the control device 140 determines whether or not the tension Td of the web W in the downstream section has reached the downstream proper tension Td3. Here, if it is determined (No) that the tension Td of the web W is lower than the downstream side proper tension Td3, this state is maintained. On the other hand, if it is determined (Yes) that the tension Td of the web W is the same as the proper tension Td3 on the downstream side, in step S21, the slow operation control is performed to maintain the tension Td of the web W in the downstream section at the proper tension Td3 on the downstream side. By performing the slow operation control, the paper-pasting operation is completed in step S22. In step S23, throwing-in is performed in the printing unit U1 so that the outer peripheral surfaces of the blanket cylinders 31a, 32a, 33a, and 34a and the outer peripheral surfaces of the blanket cylinders 31b, 32b, 33b, and 34b are brought into contact with each other with the web W interposed therebetween. Subsequently, in step S18, the paper pressing rollers 110 and 119 are moved from the disengaged position to the applied position. In this case, only the paper pressing roller 110 may be moved from the disengaged position to the applied position.

By moving the paper pressure rollers 110 and 119 to the landing position after the throw-on, the large tension momentarily acting on the web W when the paper pressure rollers 110 and 119 are moved to the landing position is relieved. That is, when the paper pressure rollers 110 and 119 are moved to the landing position between steps S17 and S19, a predetermined tension is secured in the short section between the infeed drag roller 109 and the exit drag roller 118. FIG. As a result, a large tension momentarily acts on the low-tension web W conveyed in this section, and the web W may be damaged. On the other hand, when the paper tensioning operation is completed, the tension Td of the web W reaches the downstream side proper tension Td3, and even if the paper pressing rollers 110 and 119 are moved to the landing position after throwing, the large tension instantaneously acting on the web W is relieved.

Thereafter, in step S24, the control device 140 further reduces the rotational speed of the upstream drive roller (infeed drag roller 109) to perform upstream tension control. In step S25, the control device 140 determines whether or not the tension Tu of the web W in the upstream section has become equal to or greater than the upstream proper tension Tua. Here, when it is determined (No) that the tension Tu of the web W is smaller than the upstream-side appropriate tension Tua, this state is maintained. On the other hand, when it is determined (Yes) that the tension Td of the web W is equal to or greater than the appropriate upstream tension Tua, the upstream tension control is completed by maintaining the tension of the web W in the upstream section at the upstream appropriate tension in step S26. After the printing unit U1 is accelerated in step S27, printing is started in step S28.

In the above-described embodiment, the web tension adjusting device of the present embodiment is applied to the printing units U1 to U6 of the printing apparatus U, but the configuration is not limited to this. For example, the web tension adjusting device of this embodiment can be applied to the web pass units D1 and D2 of the web pass device D. FIG. FIG. 8 is a schematic configuration diagram showing a third modification of the web tension adjusting device of the present embodiment, and FIG. 9 is a flow chart showing a web tension adjusting operation in the web pass unit.

As shown in FIG. 8, the web path device D (web path units D1 and D2) cuts the web W supplied from the printing device U (see FIG. 1) at the center in the width direction by the slitter knife 122 and the slitter drag roller 123, changes the transport path by the turn bar 141, and changes the path length by the compensators 142 and 143. The slitter drag roller 123 can be driven and rotated by a drive motor 124 . After that, the web W is sent to the folding machine F via the intermediate drag rollers 125 and 126, the paper pressure rollers 127 and 128, the tension pickup rollers 129 and 130, the triangular plate drag roller 131 and the paper pressure roller 132. The intermediate drag rollers 125 and 126 can be driven to rotate by a drive motor 133 , and the triangular plate drag roller 131 can be driven to rotate by a drive motor 134 .

The controller 140 can control the rotational speeds of the slitter drag roller 123 , the intermediate drag rollers 125 and 126 , and the triangular plate drag roller 131 by controlling the drive motors 124 , 133 and 134 . The control device 140 also receives detection values (tension of the web W) from the tension pickup rollers 129 and 130 . Here, the upstream drive rollers are the intermediate drag rollers 125 and 126 and the downstream drive roller is the triangular plate drag roller 131 .

The operation of adjusting the tension of the web W in the web pass device D will be specifically described. As shown in FIGS. 8 and 9, in step S51, control device 140 determines whether or not the paper threading operation is completed. Here, if it is determined (No) that the paper threading operation has not been completed, this state is maintained. On the other hand, if it is determined that the paper threading operation is completed (Yes), the paper threading operation is started after step S52.

In step S53, the control device 140 drives and rotates the downstream drive roller (the triangular plate drag roller 131) to perform paper tension control. Then, the slackness of the web W is eliminated in the section between the upstream driving rollers (intermediate drag rollers 125, 126) and the downstream driving roller (triangular plate drag roller 131), and tension is generated in the web W. In step S54, the control device 140 determines whether or not the tension Tm of the web W in this section has reached or exceeded the target tension Tm1 (for example, 0). As the tension Tm of the web W, the results of detection by the tension pickup rollers 129 and 130 are used. Here, if it is determined that the tension Tm of the web W is smaller than the target tension Tm1 (No), this state is maintained. On the other hand, when it is determined (Yes) that the tension Tm of the web W is equal to or higher than the target tension Tm1, in step S55, the upstream driving rollers (intermediate drag rollers 125, 126) are driven to rotate, and the upstream driving rollers (intermediate drag rollers 125, 126) are adjusted to perform low tension application control. Then, the tension of the web W increases in the section between the upstream driving rollers (intermediate drag rollers 125, 126) and the downstream driving roller (triangular plate drag roller 131).

In step S56, the control device 140 determines whether the tension Tm of the web W in the section has reached the appropriate low tension Tm2 or more. Here, if it is determined (No) that the tension Tm of the web W is smaller than the appropriate low tension Tm2, this state is maintained. On the other hand, when it is determined (Yes) that the tension Tm of the web W is equal to or higher than the proper low tension Tm2, in step S57, the control device 140 reduces the rotational speed of the upstream drive rollers (intermediate drag rollers 125 and 126) to perform proper tension application control. That is, since the rotational speed of the upstream drive roller (intermediate drag rollers 125, 126) is slower than the rotational speed of the downstream drive roller (triangular plate drag roller 131), the tension of the web W increases in the section between the upstream drive roller (intermediate drag rollers 125, 126) and the downstream drive roller (triangular plate drag roller 131).

In step S58, the control device 140 determines whether the tension Tm of the web W in the section has reached the proper tension Tm3. Here, if it is determined (No) that the tension Tm of the web W is lower than the appropriate tension Tm3, the compensators 142 and 143 are controlled in step S59, and then the process proceeds to step S60. First, the current positions of the compensators 142 and 143 are stored. Next, the tension of the web W is increased by moving the compensators 142, 143 in a direction to increase the path length of the web W. When the tension Tm of the web W becomes equal to the proper tension Tm3, the compensators 142 and 143 stop moving. On the other hand, if it is determined (Yes) that the tension Tm of the web W is the same as the appropriate tension Tm3, the control of the compensators 142 and 143 is not performed in step S59, and the process proceeds to step S60. In step S60, slow operation control is performed to maintain the tension Tm of the web W in the section at the proper tension Tm3. By performing the slow operation control, the paper-pasting operation is completed in step S61. Thereafter, in step S62, the web pass device D is accelerated, and in step S63, the compensators 142 and 143 are returned to the positions stored in step S58. After that, in step S64, printing is started. In this embodiment, not only is the rotational speed controlled, but also by increasing the path length of the web W with the compensators 142 and 143, the slack state (slackness) of the web W can quickly transition to the paper stretched state.

The process of moving the paper pressure rollers 110 and 119 from the release position to the arrival position by the control device 140 in the intermediate drag rollers 125 and 126 may be performed after the process of step S56 or after the process of step S61. Further, although the intermediate drag rollers 125 and 126 are used as the upstream drive rollers and the triangular plate drag roller 131 is used as the downstream drive roller, the slitter drag roller 123 may be used as the upstream drive roller.

So far, the section in which the printing unit U1 is arranged has been described as being applied to the web tension adjustment section by the web tension adjustment device of the present embodiment. That is, as shown in FIG. 1, the first section is from the infeed drag roller 109 to the outlet drag roller 118, the second section is from the outlet drag roller 118 to the intermediate drag rollers 125 and 126, and the third section is from the intermediate drag rollers 125 and 126 to the triangular plate drag roller 131.

In the first section, as described above, the upstream drive roller corresponds to the infeed drag roller 109, the downstream drive roller to the exit drag roller 118, the intermediate drive rollers to the blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, and 34b, the upstream tension detector to the tension pickup roller 111, and the downstream tension detector to the tension pickup roller 117. The upstream section is the section between the infeed drag roller 109 and the blanket cylinders 31 a and 31 b , and the downstream section is the section between the blanket cylinders 34 a and 34 b and the outlet drag roller 118 .

In the second section, the upstream drive roller is the outlet drag roller 118, the downstream drive rollers are intermediate drag rollers 125 and 126, the intermediate drive roller is the slitter drag roller 123, and the upstream tension detector and the downstream tension detector are not provided, but may be provided separately. The upstream section is the section between the outlet drag roller 118 and the slitter drag roller 123 , and the downstream section is the section between the slitter drag roller 123 and the intermediate drag rollers 125 and 126 .

In the third section, the upstream drive rollers are intermediate drag rollers 125 and 126, the downstream drive rollers are triangular plate drag rollers 131, there is no intermediate drive roller, and the upstream tension detector and downstream tension detector are tension pickup rollers 129 and 130, respectively.

The web tension adjustment device of the present embodiment is provided with a plurality of web tension adjustment sections (three in this embodiment) along the conveying direction of the web W, and the control device 140 adjusts the tension of the web W from the downstream web tension adjustment section in the conveying direction of the web W among the plurality of web tension adjustment sections. That is, the tension of the web W is adjusted in the order of the third section, the second section, and the first section described above.

FIG. 10 is a timing chart representing the web tension adjustment work, FIG. 11 is a timing chart representing a first modification of the web tension adjustment work, FIG. 12 is a timing chart representing a second modification of the web tension adjustment work, and FIG. 13 is a timing chart representing a third modification of the web tension adjustment work. 10 to 13, numbers (1) to (6) respectively correspond to paper tension control, low tension application control, paper pressure control, proper tension application control, slow operation control, and upstream tension control.

As shown in FIG. 10, the control device 140 performs paper feed tension control, infeed drag control, exit drag control, and intermediate drag control on the upstream side of the first section, and in each control, paper tension control, low tension application control, paper pressure control, proper tension application control, slow operation control, and upstream tension control are performed.

First, in the third section, paper tension control and low tension application control in intermediate drag control are performed. Next, in the second section, paper tension control and low tension application control in exit drag control are performed. Then, in the first section, paper tension control and low tension application control in infeed drag control are performed. Finally, paper tension control and low tension application control in paper feed tension control are performed.

Then, paper holding control, appropriate tension application control, slow operation control, and upstream tension control are simultaneously performed in intermediate drag control, exit drag control, infeed drag control, and paper feed tension control in all sections.

Further, as shown in FIG. 11, the control device 140 performs intermediate drag control, exit drag control, infeed drag control, and paper feed tension control in succession in this order. However, after completion of paper tension control and low tension application control in the third section, paper tension control and low tension application control in the second section may be started.

Further, as shown in FIG. 12, the control device 140 performs intermediate drag control, exit drag control, infeed drag control, and paper feed tension control in this order. However, when paper tension control in the third section is completed, paper tension control in the second section is started, and when paper tension control and low tension application control are completed in all sections, paper holding control, appropriate tension application control, slow operation control, and upstream tension control may be performed simultaneously.

Further, as shown in FIG. 13, the control device 140 sequentially performs intermediate drag control, exit drag control, infeed drag control, and paper feed tension control in this order, but after the paper tension control for the third section is completed, the paper tension control for the second section may be started.

The control device 140 may control only a single section or control a plurality of sections in combination, may be configured by combining a plurality of sections with some sections omitted, or may be configured to control only a single section. Also, in the above description, the section is divided into the first section, the second section, and the third section, but the second section and the third section may be combined to form the second section.

Here, the operation of adjusting the tension of the web W in the newspaper offset rotary printing press 10 will be described. FIG. 14 is a flow chart representing a printing operation.

As shown in FIGS. 1 and 14, in step S31, the paper threading work is performed, and in step S32, the controller 140 determines whether or not the paper threading work is completed. Here, if it is determined (No) that the paper threading operation has not been completed, this state is maintained. On the other hand, if it is determined that the paper threading operation is completed (Yes), in step S33, the control device 140 determines whether or not the cylinder phase alignment of the printing units is completed. Here, if it is determined (No) that cylinder phase alignment of the printing unit has not been completed, this state is maintained. On the other hand, if it is determined (Yes) that the phase alignment of the cylinders of the printing units has been completed, the tension adjustment work of the web W is started after step S35.

The control device 140 performs the tension adjustment work of the web W in the order of the third section, the second section, and the first section. Here, in the third section, tension adjustment work for the web W is performed by the control described above. In addition, in the second section, the tension adjustment work of the web W may be performed by the control as described above, or the tension adjustment work of the web W may be performed by one tension detector. Also, in the third section, the tension pickup rollers 129 and 130 are used to adjust the tension of the web W. FIG.

In step S36, it is determined whether or not the tension adjustment work for the web W in the third section has been completed. Here, if it is determined (No) that the tension adjustment work of the web W in the third section has not been completed, this state is maintained. On the other hand, if it is determined (Yes) that the tension adjustment work for the web W in the third section has been completed, it is determined in step S37 whether or not the tension adjustment work for the web W in the second section has been completed. Here, if it is determined (No) that the tension adjustment work of the web W in the second section has not been completed, this state is maintained. On the other hand, if it is determined (Yes) that the tension adjustment work for the web W in the second section has been completed, it is determined in step S38 whether or not the tension adjustment work for the web W in the first section has been completed. Here, if it is determined (No) that the tension adjustment work of the web W in the first section has not been completed, this state is maintained.

On the other hand, if it is determined that the tension adjustment work of the web W in the first section has been completed (Yes), it is determined in step S39 whether or not the tension adjustment work of the web W has been completed in all sections. Here, if it is determined (No) that the tension adjustment work of the web W has not been completed in all sections, this state is maintained. On the other hand, when it is determined that the tension adjustment work of the web W has been completed in all sections (Yes), in step S40, the control device 140 performs throw-in in which the outer peripheral surfaces of the blanket cylinders 31a, 32a, 33a, and 34a and the outer peripheral surfaces of the blanket cylinders 31b, 32b, 33b, and 34b are brought into contact with each other with the web W interposed therebetween. After that, in step S41, the control device 140 performs the upstream tension adjustment work. Then, in step S42, the control device 140 accelerates the operation to adjust the ink supply amount, and then starts printing in step S43.

A modified example of tension adjustment work for the web W in the newspaper offset rotary printing press 10 will be described. FIG. 15 is a timing chart showing a modification of the web tension adjustment work, and FIG. 16 is a flow chart showing a modification of the printing work.

The web tension adjusting section according to the modification of the web tension adjusting apparatus of the present embodiment is the entire conveying section of the web W in the newspaper offset rotary printing press 10 . Here, as shown in FIG. 1, from the paper feeding device R (brake device 107) to the infeed drag roller 109 is the first section, from the infeed drag roller 109 to the outlet drag roller 118 is the second section, from the outlet drag roller 118 to the intermediate drag rollers 125 and 126 is the third section, and from the intermediate drag rollers 125 and 126 to the triangular plate drag roller 131 is the fourth section.

In the first section, as described above, the upstream drive roller corresponds to the paper web WR (brake device 107) of the paper feeder R, the downstream drive roller corresponds to the infeed drag roller 109, there is no intermediate drive roller, and the upstream tension detector and the downstream tension detector correspond to the tension pickup roller 105.

In the second section, as described above, the upstream drive roller corresponds to the infeed drag roller 109, the downstream drive roller to the exit drag roller 118, the intermediate drive rollers to the blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, and 34b, the upstream tension detector to the tension pickup roller 111, and the downstream tension detector to the tension pickup roller 117. The upstream section is the section between the infeed drag roller 109 and the blanket cylinders 31 a and 31 b , and the downstream section is the section between the blanket cylinders 34 a and 34 b and the outlet drag roller 118 .

In the third section, the upstream drive roller is the exit drag roller 118, the downstream drive rollers are the intermediate drag rollers 125 and 126, the intermediate drive roller is the slitter drag roller 123, and the upstream tension detector and the downstream tension detector are not provided, but may be provided separately. The upstream section is the section between the outlet drag roller 118 and the slitter drag roller 123 , and the downstream section is the section between the slitter drag roller 123 and the intermediate drag rollers 125 and 126 .

In the fourth section, the upstream drive rollers are intermediate drag rollers 125 and 126, the downstream drive rollers are triangular plate drag rollers 131, there is no intermediate drive roller, and the upstream tension detector and downstream tension detector are tension pickup rollers 129 and 130, respectively.

The web tension adjustment device of the present embodiment is provided with a plurality of web tension adjustment sections (four in this embodiment) along the transport direction of the web W, and the control device 140 adjusts the tension of the web W from the upstream web tension adjustment section in the web W transport direction among the plurality of web tension adjustment sections. That is, the tension of the web W is adjusted in the order of the first section, second section, third section, and fourth section described above.

As shown in FIG. 15, the control device 140 performs paper feed tension control, infeed drag control, exit drag control, and intermediate drag control on the upstream side of the first section, and in each control, paper tension control, low tension application control, paper pressure control, proper tension application control, slow operation control, and upstream tension control are performed.

First, in the first section, paper tension control and low tension application control in paper feed tension control are performed. In the second section, paper tension control and low tension application control in infeed drag control are performed. In the third section, paper tension control and low tension application control in exit drag control are performed. In the fourth section, paper tension control and low tension application control in intermediate drag control are performed.

Paper holding control, appropriate tension application control, slow operation control, and upstream tension control are simultaneously performed in paper feed tension control, infeed drag control, exit drag control, and intermediate drag control in all sections. Note that the paper feed tension control, infeed drag control, exit drag control, and intermediate drag control by the control device 140 are not limited to those described above, and may be the control described with reference to FIGS. 11 to 13 .

As shown in FIGS. 1 and 16, in step S71, the paper threading work is performed, and in step S72, the control device 140 determines whether or not the paper threading work is completed. Here, if it is determined (No) that the paper threading operation has not been completed, this state is maintained. On the other hand, if it is determined that the paper threading operation is completed (Yes), in step S73, the control device 140 determines whether or not the cylinder phase matching of the printing units is completed. Here, if it is determined (No) that cylinder phase alignment of the printing unit has not been completed, this state is maintained. On the other hand, if it is determined (Yes) that the phase alignment of the cylinders of the printing units has been completed, the tension adjustment work of the web W is started after step S75.

The control device 140 performs tension adjustment work for the web W in the order of the first section, the second section, the third section, and the fourth section. Here, in the first section, tension adjustment work for the web W is performed by the control described above. In the second section, tension adjustment work for the web W is performed by the control described above. In the third section, tension adjustment work for the web W is performed by the control described above. In the fourth section, tension adjustment work for the web W is performed by the control described above.

At step S76, it is determined whether or not the tension adjustment work for the web W in the first section has been completed. Here, if it is determined (No) that the tension adjustment work of the web W in the first section has not been completed, this state is maintained. On the other hand, if it is determined (Yes) that the tension adjustment work of the web W in the first section has been completed, it is determined in step S77 whether or not the tension adjustment work of the web W has been completed in the second section. Here, if it is determined (No) that the tension adjustment work of the web W in the second section has not been completed, this state is maintained. On the other hand, if it is determined (Yes) that the tension adjustment work for the web W in the second section has been completed, it is determined in step S78 whether or not the tension adjustment work for the web W in the third section has been completed. Here, if it is determined (No) that the tension adjustment work of the web W in the third section has not been completed, this state is maintained.

On the other hand, if it is determined (Yes) that the tension adjustment work for the web W in the third section has been completed, it is determined in step S79 whether or not the tension adjustment work for the web W in the fourth section has been completed. Here, if it is determined (No) that the tension adjustment work of the web W in the fourth section has not been completed, this state is maintained. On the other hand, if it is determined (Yes) that the tension adjustment work for the web W has been completed in the fourth section, it is determined in step S80 whether or not the tension adjustment work for the web W has been completed in all sections. Here, if it is determined (No) that the tension adjustment work of the web W has not been completed in all sections, this state is maintained. On the other hand, when it is determined that the tension adjustment work of the web W has been completed in all sections (Yes), in step S81, the control device 140 causes the outer peripheral surfaces of the blanket cylinders 31a, 32a, 33a, and 34a to come into contact with the outer peripheral surfaces of the blanket cylinders 31b, 32b, 33b, and 34b with the web W interposed therebetween. After that, in step S82, the controller 140 accelerates and performs the ink supply amount adjustment work, and then starts printing in step S83.

As described above, in the web tension adjusting device of the present embodiment, the infeed drag roller (upstream driving roller) 109 and the exit drag roller (downstream driving roller) 118 which are arranged at predetermined intervals in the conveying direction of the web W and are capable of conveying the web W, the blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, and 34b arranged between the infeed drag roller 109 and the exit drag roller 118, and the upstream A tension pickup roller (upstream tension detector) 111 that detects the tension of the web W in the side section, a tension pickup roller (downstream tension detector) 117 that detects the tension of the web W in the downstream section, and a control device 140 that can adjust the tension of the web W by controlling the rotational speed of the infeed drag roller 109 based on the detection results of the tension pickup roller 111 and the tension pickup roller 117.

Therefore, the tension of the web W is adjusted by controlling the rotational speed of the in-feed drag roller 109 based on the tension of the web W in the upstream section and the tension of the web W in the downstream section with respect to the blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, and 34b. Even with 4b, the tension of the web W in the upstream section and the tension of the web W in the downstream section can be properly adjusted. As a result, the tension of the web W can be properly adjusted, and the workability of the work for adjusting the tension of the web W can be improved.

In the web tension adjusting device of the present embodiment, the control device 140 adjusts the tension of the web W in the downstream section to the preset downstream proper tension, and then adjusts the tension of the web W in the upstream section to the preset upstream proper tension. Therefore, when the tension of the web W is adjusted to the proper tension on the upstream side, the tension of the web W already adjusted to the proper tension on the downstream side does not fluctuate, and the tension of the web W can be adjusted efficiently.

In the web tension adjusting device of the present embodiment, the control device 140 makes the rotational speed of the infeed drag roller 109 lower than the rotational speed of the outlet drag roller 118, and when the tension of the web W in the downstream section reaches the proper downstream tension, controls the rotational speed of the infeed drag roller 109 so that the proper downstream tension is maintained. Therefore, the tension of the web W can be easily increased, and when the tension of the web W in the downstream section is adjusted to the proper tension on the downstream side, the rotation speed of the in-feed drag roller 109 is controlled so that the proper tension on the downstream side is maintained, so the tension of the web W can be adjusted efficiently.

In the web tension adjusting device of the present embodiment, when the tension of the web W in the downstream section reaches a preset downstream proper low tension lower than the downstream proper tension, the control device 140 changes, for example, decelerates, the rotational speed of the in-feed drag roller 109 to adjust it to the proper tension. Therefore, the tension of the web W is increased in stages, and breakage of the web W due to a sudden increase in tension can be suppressed.

In the web tension adjusting device of the present embodiment, paper pressure rollers 110 and 119 are provided that sandwich the web W by coming into contact with at least one of the infeed drag roller 109 and the exit drag roller 118, and the control device 140 moves the paper pressure rollers 110 and 119 from the release position to the arrival position when the tension of the web W in the downstream section reaches the downstream appropriate low tension. Therefore, the tension of the web W is increased while the web W is nipped by the infeed drag roller 109, the exit drag roller 118, and the paper pressure rollers 110, 119. By stably supporting the web W, breakage of the web W can be suppressed.

In the web tension adjusting device of the present embodiment, paper pressing rollers 110 and 119 are provided to hold the web W by coming into contact with at least one of the infeed drag roller 109 and the exit drag roller 118. After adjusting the tension of the web W in the downstream section to the appropriate downstream tension, the control device 140 controls the blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, and 34 at the separated positions. b to the contact position, and then the paper pressing rollers 110 and 119 are moved from the release position to the arrival position. Therefore, when the web W is nipped between the infeed drag roller 109, the exit drag roller 118, and the paper pressure rollers 110, 119, the tension of the web W is already adjusted to the proper tension on the downstream side, and the momentary increase in the tension on the web W is suppressed, and the breakage of the web Q can be suppressed.

In the web tension adjusting device of the present embodiment, the control device 140 adjusts the tension of the web W in the upstream section to the preset upstream tension for adjusting the downstream tension, and then, when the tension of the web W in the downstream section reaches the preset downstream proper tension, adjusts the tension of the web W in the upstream section to the preset upstream proper tension. Therefore, it is possible to increase the tension of the web W at an early stage and adjust the tension of the web W to the proper tension on the upstream side.

In the web tension adjusting device of the present embodiment, the control device 140 makes the rotation speed of the infeed drag roller 109 lower than the rotation speed of the outlet drag roller 118, and when the tension of the web W in the downstream section reaches the appropriate downstream tension, controls the rotation speed of the infeed drag roller 109 so that the current tension of the web W is maintained. Therefore, the tension of the web W can be adjusted efficiently.

In the web tension adjusting device of the present embodiment, the control device 140 adjusts the tension of the web W in the downstream section to the appropriate downstream tension, moves the blanket cylinders 31 a, 31 b, 32 a, 32 b, 33 a, 33 b, 34 a, and 34 b in the separated position to the contact position, and then adjusts the web tension in the upstream section to the appropriate upstream tension. Therefore, the blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, and 34b are moved to the contact position in a state in which the tension of the web W is adjusted to the proper tension on the downstream side, and breakage of the web W can be suppressed.

In the web tension adjusting device of the present embodiment, the control device 140 starts the driving rotation of the exit drag roller 118 in a state where the driving rotation of the infeed drag roller 109 is stopped, and when the tension of the web W in the downstream section increases, the driving rotation of the infeed drag roller 109 is started. Therefore, the slackness of the web W can be quickly eliminated.

In the web tension adjusting device of this embodiment, some of the blanket cylinders 31a, 32b, 33a, and 34b contact the web W when the blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, and 34b are at the separated positions. Therefore, even if some of the blanket cylinders 31a, 32b, 33a, 34b are in contact with the web W, the tension of the web W in the upstream section and the tension of the web W in the downstream section can be properly adjusted. As a result, the workability of the work for adjusting the tension of the web W can be improved.

In the web tension adjusting device of the present embodiment, compensators 142 and 143 capable of changing the path length of the web W are provided between the intermediate drag rollers 125 and 126 and the triangular plate drag roller 131, and the controller 140 controls the compensators 142 and 143 based on the detection results of the tension pickup rollers 129 and 130 to adjust the tension of the web W. Therefore, the tension of the web W can be adjusted early by combining with the method of controlling the rotation speed of the intermediate drag rollers 125 and 126 and the triangular plate drag roller 131 .

In the web tension adjusting device of the present embodiment, a plurality of web W tension adjusting sections are provided along the web W conveying direction, and the control device 140 adjusts the tension of the web W from the web W tension adjusting section on the downstream side in the web W conveying direction among the plurality of web W tension adjusting sections. Therefore, when adjusting the tension of the web W in the tension adjustment section on the upstream side, the tension of the web W can be adjusted efficiently without changing the tension of the web W in the tension adjustment section on the downstream side which has already been adjusted.

In the web tension adjusting device of the present embodiment, a plurality of web W tension adjusting sections are provided along the web W conveying direction, and the control device 140 adjusts the tension of the web W from the upstream web W tension adjusting section in the web W conveying direction among the plurality of web W tension adjusting sections. Therefore, when adjusting the tension of the web W in the tension adjustment section on the downstream side, the tension of the web W can be adjusted efficiently without changing the tension of the web W in the tension adjustment section on the upstream side that has already been adjusted.

Further, the tension adjustment method of the present embodiment includes a step of detecting the tension of the web W in the upstream section, a step of detecting the tension of the web W in the downstream section, and a step of adjusting the tension of the web W by controlling the rotational speed of the in-feed drag roller 109 based on the tension of the web W in the upstream section and the tension of the web W in the downstream section. Therefore, even if there are blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, 34b between the upstream section and the downstream section, the tension of the web W in the upstream section and the tension of the web W in the downstream section can be properly adjusted. As a result, the tension of the web W can be properly adjusted, and the workability of the work for adjusting the tension of the web W can be improved.

Further, the printing machine of this embodiment includes a paper feeding device R that supplies the web W, a printing device U that prints on the web W supplied from the paper feeding device R, a folding machine F that vertically folds the web W printed by the printing device U and then cuts it to form a predetermined signature, and a tension adjusting device for the web W. Therefore, the tension of the web W can be properly adjusted, and the workability of the work for adjusting the tension of the web W can be improved.

In the printing press of this embodiment, the sheet feeding device R has a plurality of sheet feeding units R1 to R7, the printing device U has a plurality of printing units U1 to U6, and the folding machine F forms a predetermined signature by cutting a plurality of webs W after vertically folding them. b, 32a, 32b, 33a, 33b, 34a, 34b are moved to the contact position. Therefore, the blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, and 34b come into contact with all the webs W at the same time, and breakage of the webs W can be suppressed.

In addition, since the tension of the web W is quickly adjusted to the appropriate tension on the downstream side and the throwing is performed in a state where the tension on the downstream side is established, stable printing can be realized from the start of printing, and wasted paper can be reduced (reduced black loss). In addition, since paper attachment is completed in low-speed operation, the speed of the web W during throwing can be reduced, and wasted paper can be reduced (white loss reduction). Furthermore, since the paper tensioning operation can be performed automatically, the skill of the operator who monitors the tension of the web W and operates the machine is not required, and the operator's skillless operation and automatic unmanned operation at the start of printing can be realized.

In the above-described embodiment, the upstream drive roller, the downstream drive roller, the intermediate drive roller, the upstream tension detector, and the downstream tension detector are arranged at proper positions. However, the web tension adjusting device is not limited to this configuration, and for example, the web transport path may be divided into two or four or more sections and each component may be arranged at appropriate positions.

In the above-described embodiment, the blanket cylinders 31a, 31b, 32a, 32b, 33a, 33b, 34a, and 34b are arranged as intermediate drive rollers between the upstream section and the downstream section.

In the above-described embodiment, the tension pickup roller is used as the upstream tension detector and the downstream tension detector, but the configuration is not limited to this, and any tension detector such as a dancer roller may be used as long as it can detect the tension of the web.

Further, in the above-described embodiments, the printing press of the present invention is applied to a newspaper offset rotary printing press, but it may be applied to other printing presses that use a web, such as a commercial offset rotary printing press, and may be a double-sided printing press or a single-sided printing press.

R paper feeding device R1 to R7 paper feeding unit I infeed device I1 to I7 infeed unit U printing device U1 to U6, U11 to U62 printing unit D web pass device D1, D2 web pass unit F folding machine F1, F2 folding unit 21, 22, 23, 24 stack 31a, 31b, 32a, 32b, 33a, 33b, 34a, 3 4b Blanket cylinder 41a, 41b, 42a, 42b, 43a, 43b, 44a, 44b Plate cylinder 51a, 51b, 52a, 52b, 53a, 53b, 54a, 54b Ink supply device 61a, 61b, 62a, 62b, 63a, 63b, 64a, 64b Dampening device 101 Holding arm 10 2 guide roller 103 floating roller 104 guide roller 105 tension pickup roller 106 guide roller 107 brake device 108 guide roller 109 infeed drag roller 110 paper pressing roller 111 tension pickup roller 112 drive motor 113, 114, 115, 116 drive motor 117 tension pickup roller 118 exit drag roller 119 paper press Feed roller 120 Guide roller 121 Drive motor 122 Slitter knife 123 Slitter drag roller 124 Drive motor 125, 126 Intermediate drag roller 127, 128 Paper holding roller 129, 130 Tension pickup roller 131 Triangular plate drag roller 132 Paper holding roller 133 Drive motor 134 Drive motor 140 Control device 141 Turn bar 142, 143 Compensator (path length changing device)
WR Roll paper W Web

Claims (16)

an upstream drive roller and a downstream drive roller which are arranged at a predetermined interval in the web transport direction and are capable of transporting the web;
an intermediate driving roller disposed between the upstream driving roller and the downstream driving roller and capable of conveying the web;
an upstream tension detector that detects the tension of the web in an upstream section on the upstream side in the conveying direction of the web from the intermediate drive roller;
a downstream tension detector that detects the tension of the web in a downstream section downstream of the intermediate driving roller in the conveying direction of the web;
a control device capable of adjusting the tension of the web by controlling the rotation speed of the upstream driving roller based on the detection results of the upstream tension detector and the downstream tension detector;
with
The control device makes the rotational speed of the upstream drive roller lower than the rotational speed of the downstream drive roller, adjusts the web tension in the downstream section to a preset downstream proper tension, and then adjusts the web tension in the upstream section to the preset upstream proper tension.
A web tension adjusting device characterized by: 2. The web tension adjusting device according to claim 1 , wherein the rotational speed of the upstream drive roller is set lower than the rotational speed of the downstream drive roller, and when the tension of the web in the downstream section reaches the proper downstream tension, the control device controls the rotational speed of the upstream drive roller so that the proper downstream tension is maintained. an upstream drive roller and a downstream drive roller which are arranged at a predetermined interval in the web transport direction and are capable of transporting the web;
an intermediate driving roller disposed between the upstream driving roller and the downstream driving roller and capable of conveying the web;
an upstream tension detector that detects the tension of the web in an upstream section on the upstream side in the conveying direction of the web from the intermediate drive roller;
a downstream tension detector that detects the tension of the web in a downstream section downstream of the intermediate driving roller in the conveying direction of the web;
a control device capable of adjusting the tension of the web by controlling the rotation speed of the upstream driving roller based on the detection results of the upstream tension detector and the downstream tension detector;
with
The control device makes the rotational speed of the upstream drive roller lower than the rotational speed of the downstream drive roller, adjusts the web tension in the upstream section to a preset downstream tension adjustment upstream tension, and then adjusts the web tension in the upstream section to the preset upstream proper tension when the web tension in the downstream section reaches a preset downstream proper tension.
A web tension adjusting device characterized by: 4. The web tension adjusting device according to claim 3 , wherein the control device makes the rotational speed of the upstream drive roller lower than the rotational speed of the downstream drive roller, and controls the rotational speed of the upstream drive roller so that the current tension of the web is maintained when the tension of the web in the downstream section reaches the appropriate downstream tension. The web tension adjustment device according to any one of claims 1 to 4, wherein when the tension of the web in the downstream section reaches a preset downstream proper low tension that is lower than the downstream proper tension, the control device changes the rotational speed of the upstream drive roller to adjust the tension to the proper tension. 6. The web tension adjusting device according to claim 5, further comprising: a pressure roller that pinches the web by contacting at least one of the upstream drive roller and the downstream drive roller, and wherein the control device moves the pressure roller from the disengaged position to the applied position when the tension of the web in the downstream section reaches the appropriate low tension on the downstream side. The web tension adjusting device according to any one of claims 1 to 6, further comprising: a pressure roller that pinches the web by contacting at least one of the upstream drive roller and the downstream drive roller, and the control device adjusts the tension of the web in the downstream section to the proper downstream tension, moves the intermediate drive roller at the separated position to the contact position, and then moves the pressure roller from the disengaged position to the on position. The web tension adjusting device according to any one of claims 1 to 7 , wherein the control device adjusts the tension of the web in the downstream section to the proper downstream tension, moves the intermediate driving roller from the separated position to the contact position, and then adjusts the tension of the web in the upstream section to the proper upstream tension. The web tension adjusting device according to any one of claims 1 to 8 , wherein the control device starts the driving rotation of the downstream driving roller in a state where the driving rotation of the upstream driving roller is stopped, and when the tension of the web in the downstream section increases, the driving rotation of the upstream driving roller is started. The web tension adjusting device according to any one of claims 1 to 9 , wherein the intermediate drive rollers are a pair of blanket cylinders in a printing apparatus, and are movable between a separated position where a gap is secured between the pair of blanket cylinders and a contact position where there is no gap between the pair of blanket cylinders, and at least one of the pair of blanket cylinders contacts the web when the pair of blanket cylinders is in the separated position. The web tension adjusting device according to any one of claims 1 to 10 , wherein a path length changing device capable of changing the path length of the web is provided between the upstream drive roller and the downstream drive roller, and the control device controls the path length changing device to adjust the tension of the web based on the detection result of the upstream tension detector or the downstream tension detector. The web tension adjustment device according to any one of claims 1 to 11 , wherein a plurality of web tension adjustment sections are provided between the upstream drive roller and the downstream drive roller along the web transport direction, and the control device adjusts the tension of the web from the web tension adjustment section on the downstream side in the web transport direction among the plurality of web tension adjustment sections. The web tension adjustment device according to any one of claims 1 to 11 , wherein a plurality of web tension adjustment sections are provided between the upstream drive roller and the downstream drive roller along the web transport direction, and the control device adjusts the tension of the web from the upstream web tension adjustment section in the web transport direction among the plurality of web tension adjustment sections. an upstream drive roller and a downstream drive roller which are arranged at a predetermined interval in the web transport direction and are capable of transporting the web;
an intermediate driving roller disposed between the upstream driving roller and the downstream driving roller and capable of conveying the web;
with
a step of detecting the tension of the web in an upstream section on the upstream side in the conveying direction of the web from the intermediate drive roller;
a step of detecting the tension of the web in a downstream section on the downstream side in the conveying direction of the web from the intermediate driving roller;
adjusting the tension of the web by controlling the rotational speed of the upstream drive roller based on the tension of the web in the upstream section and the tension of the web in the downstream section;
has
After the rotational speed of the upstream drive roller is set lower than the rotational speed of the downstream drive roller, and the tension of the web in the upstream section is adjusted to a preset upstream tension for adjusting downstream tension, when the tension of the web in the downstream section reaches a preset downstream proper tension, the tension of the web in the upstream section is adjusted to the preset upstream proper tension.
A web tension adjustment method characterized by: a paper feeding device for feeding a web;
a printing device that prints on the web supplied from the paper feeding device;
a folding device for vertically folding the web printed by the printing device and then cutting the web to form a predetermined signature;
A web tension adjusting device according to any one of claims 1 to 13 ;
A printing press comprising: The paper feeding device has a plurality of paper feeding units, the printing device has a plurality of printing devices, the folding device vertically folds the plurality of webs printed by the printing devices and then cuts them to form a predetermined signature, wherein the control device moves the intermediate drive roller from the spaced position to the contacting position when the tension of the web in all the downstream sections of the plurality of web transport paths is adjusted to a preset downstream proper tension. 16. The printing press according to Item 15 .

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