JP5891677B2 - Offset printing machine and printing method - Google Patents

Description

  The present invention relates to an offset printing machine and a printing method for printing on a continuously conveyed elongated web, and in particular, reduces the burden on workers because it is not necessary to preset a compensator roller when printing the web. The present invention relates to an offset printing machine and a printing method that can reduce the amount of waste paper generated.

  Various types of offset printing presses (rotary presses) that perform printing on elongated webs that are continuously conveyed are known. In such an offset printing machine, the color tone and the folding position are adjusted when the web is printed. More specifically, the ink supply amount is adjusted so that the color tone matches the color sample, and the operator confirms the booklet discharged from the folding machine connected to the printing machine with respect to the folding position. The folding position is adjusted by this. Then, when the color tone and folding position are in a desired state, production as a product is started.

  Conventionally, the time required for adjusting the color tone and the folding position and the paper (scrap paper) have been problems, and it is required to reduce the reduction of the waste paper generated during printing. In particular, with regard to the color tone, a technique has been developed in which the ink consumption is predicted for each part of the pattern and the ink supply device is preset by scanning the printing plate and calculating the image rate. In particular, with the widespread use of CTP, a system for directly calculating the area ratio from the pattern data and presetting the ink supply amount has been established. As a result, it is now possible to perform printing with a color tone almost similar to a sample at the time of printing.

  On the other hand, there are three types of web folding operations by the folding machine: former folding, parallel folding, and chopper folding, and it is necessary to adjust the folding position for each. For the former folding, the web guide system (for example, CPC, etc.) installed before entering the web folding machine, the center of the web and the center of the machine (triangular plate) are aligned, and almost no human adjustment is required. It is in a state. For chopper folding, adjustment is required by moving the triangular plate when changing the paper width or when wrapping the print book, etc., but printing can be done by presetting the triangular plate position based on geometric calculation values. There is little need to make adjustments after the start. On the other hand, regarding the folding position (cutting position (cutoff position)) in parallel folding, not only the web path route is changed due to a change in folding specifications, but also various other factors (such as the type of paper changes depending on the item). ) Due to a change in the amount of paper elongation due to the above, there is a problem that it changes at every printing.

  As for parallel folding, at present, as disclosed in, for example, Patent Document 1, the position of the compensator roller is adjusted by an operator at the time of printing, so that the parallel folding position (cutting position (cut-off position)) is set. After the adjustment, a method of maintaining the adjusted parallel folding position using a cutoff controller that maintains the path length of the web at a desired size is used. However, in such a method, there is a problem that adjustment by preset cannot be omitted. Also, when the amount of paper elongation changes due to the slowdown of the web speed at the end of printing, the cut-off controller follows the change in the amount of paper elongation, and the position of the compensator roller changes from the good position during production. There is a problem of shifting.

  Also, for parallel folding, the compensator roller position data of the same paper has been collected, and measures such as presetting the position of the compensator roller based on that data have been taken, but until now, sufficient effects can be obtained. could not. This is because the amount of paper elongation, one of the major causes of misalignment of the parallel folding position, is the temperature and humidity of the atmosphere where the offset printing machine is installed, the temperature and air volume of the dryer, the draw rate of the web, the amount of dampening water of the unit, etc. This is because, due to various influences, the amount of paper expansion differs greatly in the past data even for the same paper.

  As described above, in parallel folding, there is a problem that the time required for adjusting the folding position becomes long, and printing yield loss occurs, resulting in a decrease in yield.

JP-A-62-101442

  In a printing factory, work on the same paper is often assigned to the same machine in a row, such as a flyer for each region or a page difference in a magazine. In such a case, after the production is finished, the cut-off controller is turned off, the web transport is stopped, the item is switched, and the web feed speed reaches the quality confirmation speed. Turn on the controller. This eliminates the movement of the compensator roller in response to changes in the amount of paper stretch due to deceleration at the end of production, and when the web transport speed reaches the production speed after printing is finished, the paper before switching items Since it matches the amount of elongation, the cutting position of the web is the original position. In this case, it is not necessary to preset the compensator roller, and the cutting position with respect to the web can be matched without adjusting the position of the compensator roller.

  The present invention has been made in consideration of the above points, and the cut-off controller is switched on / off while the web conveyance speed is constant, and the printing operation for one web is completed. The web transport speed when the cut-off controller operation is turned off coincides with the web transport speed when the cut-off controller operation is turned on when the printing operation for another web is subsequently started. Accordingly, there is no need to preset the compensator roller at the time of printing the web, thereby reducing the burden on the operator and providing an offset printing machine and a printing method capable of reducing the amount of waste paper generated. For the purpose.

  The offset printing machine of the present invention is an offset printing machine that performs printing on an elongated web that is continuously conveyed, and includes a feeding unit that feeds a wound web, and a web fed from the feeding unit. A printing unit that prints on a web that is conveyed by the conveyance unit, a cutting unit that cuts a web that is conveyed by the conveyance unit and printed by the printing unit, and the printing A cut-off controller that adjusts the path length of the web between the cutting unit and the cutting unit, and a control unit that controls the transport unit and the cut-off controller, and the control unit performs a printing operation on one web. When the cut-off controller is turned off while the web conveyance speed of the conveyance unit is constant. When the adjustment of the path length of the web by the troller is stopped and then the printing operation for one web is finished and the printing operation for the other web is started, the web conveyance speed by the conveyance unit is constant. When the operation of the cutoff controller is turned on in the state, the conveyance unit and the cutoff controller are controlled to resume the adjustment of the web path length by the cutoff controller, and the printing operation for one web is finished. When the operation of the cut-off controller is turned off, the web transport speed when the web is transported by the transport unit, and when the operation of the cut-off controller is turned on when the printing operation for another web is started, It is characterized in that the web conveyance speed by the above is coincident.

  According to such an offset printing machine, when the printing operation for one web is finished, the cut-off controller is turned off by turning off the operation of the cut-off controller while the web conveyance speed is constant. When the adjustment of the web path length is stopped and then the printing operation for one web is completed and the printing operation for the other web is started, the cutoff controller When the operation is turned on, the adjustment of the web path length by the cut-off controller is resumed. This eliminates the need for presetting the compensator roller when printing the web, thereby reducing the burden on the operator. Also, the web transport speed when the cut-off controller operation was turned off when the print operation for one web was completed, and the cut-off controller operation was turned on when the print operation for another web was started. Since the web conveyance speed at the time coincides with the web, the web expansion amount matches before and after the switching of the printing item. Therefore, even in the printing operation after the switching of the printing item, the web cutting position. Is the same position as the printing operation before switching the print items. For this reason, it is not necessary to adjust the cutting position of the web at the time of printing the web, and the amount of waste paper generated can be reduced.

  In the offset printing machine of the present invention, when the printing operation for one web is finished and the printing operation for another web is started, the control unit is configured such that the web conveyance speed by the conveyance unit is set to the web. When the conveyance unit is controlled so as to have a constant quality confirmation speed smaller than the normal printing speed when performing normal printing, and the operation of the cut-off controller is turned off when the printing operation for one web is finished. The web transport speed by the transport section and the web transport speed by the transport section when the operation of the cut-off controller is turned on when starting the printing operation for another web are the quality confirmation speeds, respectively. It is preferable.

  The offset printing machine according to the present invention further includes a tension detection unit that detects a tension of the web conveyed by the conveyance unit, and the control unit uses the conveyance unit when the printing operation for one web is finished. The cut-off controller is turned off by turning off the operation of the cut-off controller when the web tension detected by the tension detecting unit becomes a constant magnitude while the web conveyance speed is constant. When the adjustment of the web path length is stopped, and then the printing operation for one web is finished and the printing operation for the other web is started, the web conveyance speed by the conveyance unit is constant. When the web tension detected by the tension detector becomes a certain level, the cut-off controller is turned on. It is preferable to control the transport section and the cut-off controller so as to resume adjustment of the path length of the web by the cut-off controller by Rukoto.

  In the offset printing machine of the present invention, the cut-off controller is provided between the printing unit and the cutting unit, and moves the compensator roller around which the web conveyed by the conveyance unit is wound, and the compensator roller A compensator roller drive unit and a register mark detection sensor for detecting a register mark attached to the web conveyed by the conveying unit, and the cut-off controller is operated when the cut-off controller is turned on. A path length of the web between the printing unit and the cutting unit by adjusting the position of the compensator roller by controlling the compensator roller driving unit based on the registration mark detected by the registration mark detection sensor While adjusting the cut-off controller Operation when it is turned off is preferably adapted to fix the position of the compensator roller.

  The printing method of the present invention is an offset printing machine that performs printing on an elongated web that is continuously conveyed, and includes a sending unit that sends a wound web, and a web sent from the sending unit. A conveying unit that conveys; a printing unit that performs printing on a web that is conveyed by the conveying unit; a cutting unit that trims a web that is conveyed by the conveying unit and printed by the printing unit; and the printing unit And a cut-off controller that adjusts the path length of the web between the cutting unit and a printing method for printing on the web with an offset printing machine, when the printing operation for one web is finished The cut-off controller turns off the operation of the cut-off controller in a state where the web conveyance speed by the conveyance unit is constant. A step of stopping the adjustment of the web path length between the printing unit and the cutting unit, and when the printing operation for one web is finished and the printing operation for the other web is started, Resuming the adjustment of the web path length between the printing unit and the cutting unit by the cut-off controller by turning on the operation of the cut-off controller in a state where the conveyance speed is constant; The web transport speed by the transport unit when the operation of the cut-off controller is turned off when the print operation for one web is finished, and the cut-off when the print operation for another web is started. The web conveyance speed by the conveyance unit when the operation of the controller is turned on coincides with the controller. .

  According to such a printing method, when the printing operation for one web is ended, the web of the cut-off controller is turned off by turning off the operation of the cut-off controller while the web transport speed is constant. The cut-off controller operates with the web transport speed being constant when the adjustment of the path length of the web is stopped and then the printing operation for one web is completed and the printing operation for the other web is started. By turning on, the adjustment of the web path length by the cut-off controller is resumed. This eliminates the need for presetting the compensator roller when printing the web, thereby reducing the burden on the operator. Also, the web transport speed when the cut-off controller operation was turned off when the print operation for one web was completed, and the cut-off controller operation was turned on when the print operation for another web was started. Since the web conveyance speed at the time coincides with the web, the web expansion amount matches before and after the switching of the printing item. Therefore, even in the printing operation after the switching of the printing item, the web cutting position. Is the same position as the printing operation before switching the print items. For this reason, it is not necessary to adjust the cutting position of the web at the time of printing the web, and the amount of waste paper generated can be reduced.

  In the printing method of the present invention, when the printing operation for one web is finished and the printing operation for the other web is started, the web conveyance speed by the conveyance unit is set to perform normal printing on the web. The web is conveyed so as to have a constant quality confirmation speed smaller than the normal printing speed of the above, and the conveyance when the operation of the cut-off controller is turned off when the printing operation for one web is finished. It is preferable that the web conveyance speed by the conveyance section and the web conveyance speed by the conveyance section when the operation of the cut-off controller is turned on when starting the printing operation for another web are the quality confirmation speed, respectively. .

  According to the offset printing machine and the printing method of the present invention, it is not necessary to preset the compensator roller at the time of printing the web, so that the burden on the operator can be reduced and the amount of waste paper generated can be reduced. .

It is a side view which shows the structure of the offset printing press in embodiment of this invention. It is a graph which shows transition of the conveyance speed of the web in the offset printing machine shown in FIG. 1, and ON / OFF of a cutoff controller. It is a graph which shows transition of the conveyance speed of the web in the conventional offset printing machine, and the on / off of a cutoff controller as a comparative example.

  Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are diagrams illustrating an offset printing machine and a printing method according to the present embodiment.

  The offset printing machine according to the present embodiment performs printing on the elongated web W that is continuously conveyed. As shown in FIG. 1, the offset printing machine according to the present embodiment includes a feed roll 10 on which a web W is wound and a wound web W is fed, and a web W sent from the feed roll 10. A printing unit 12 that performs printing and a cutting unit 14 that cuts the web W printed by the printing unit 12 are provided. A cut-off controller 30 that adjusts the path length of the web W between the printing unit 12 and the cutting unit 14 is provided between the printing unit 12 and the cutting unit 14. Further, the offset printing machine according to the present embodiment is provided with a tension detection unit 40 that detects the tension of the web W between the printing unit 12 and the cutting unit 14.

  Hereinafter, each component of such an offset printing machine will be described in detail.

  The printing unit 12 includes a pair of rollers 12a and 12b. When one roller 12a is pressed against the other roller 12b, a nip portion is formed between the rollers 12a and 12b. It has become. The web W fed from the feed roll 10 passes through a nip formed between the rollers 12a and 12b. One roller 12a is provided with a plate surface, and when the web W passes through the nip portion, the ink transferred from the ink supply unit (not shown) to the plate surface of the roller 12a is transferred from the roller 12a to the web W. It is like that. Further, a roller driving unit 16 is connected to the other roller 12b, and the other roller 12b is rotationally driven by the roller driving unit 16.

  The cut-off controller 30 is provided between the printing unit 12 and the cutting unit 14, and includes a compensator roller 32 around which the web W fed from the feed roll 10 is wound, and a guide for guiding the compensator roller 32 in the vertical direction in FIG. A guide 34 and a compensator roller driving unit 36 that moves the compensator roller 32 along the guide guide 34 are provided. The cut-off controller 30 is provided with a registration mark detection sensor 38 that detects a registration mark attached to the web W on the downstream side of the compensator roller 32 in the web W conveyance direction.

  The cut-off controller 30 controls the compensator roller drive unit 36 based on the register mark on the web W detected by the register mark detection sensor 38 when the operation of the cut-off controller 30 is on, thereby controlling the compensator. The roller 32 is moved in the vertical direction in FIG. 1 along the guide guide 34, and the position of the compensator roller 32 is adjusted. Thereby, the cut-off controller 30 adjusts the path length of the web W between the printing unit 12 and the cutting unit 14 to a desired size. On the other hand, when the operation of the cutoff controller 30 is OFF, the compensator roller driving unit 36 does not move the compensator roller 32. For this reason, the position of the compensator roller 32 is fixed.

  The tension detection unit 40 includes a tension detection roller 42 around which the web W is wound, and a load cell 44 that detects a force applied to the tension detection roller 42 by the web W. The tension detection unit 40 detects the tension of the web W based on the force detected by the load cell 44 and applied to the tension detection roller 42 by the web W.

  The cutting portion 14 is composed of a pair of rollers 14a and 14b, and when one roller 14a is pressed against the other roller 14b, a nip portion is formed between these rollers 14a and 14b. It has become. The web W passes through a nip portion formed between the rollers 14a and 14b. A blade 14c is provided on the outer peripheral surface of one roller 14a, and the web W is cut by the blade 14c when the web W passes through the nip portion. Further, a roller driving unit 16 is connected to the other roller 14b, and the other roller 14b is rotationally driven by the roller driving unit 16.

  As described above, the roller driving unit 16 rotationally drives the roller 12b of the printing unit 12 and the roller 14b of the cutting unit 14. The roller driving unit 16 constitutes a transport unit that continuously transports the web W.

  The offset printing machine according to the present embodiment is provided with a control unit 50 that controls each component of the offset printing machine, such as the roller driving unit 16 and the cutoff controller 30. The control unit 50 controls the roller driving unit 16 to adjust the web W conveyance speed. Further, the control unit 50 can switch the cut-off controller 30 on / off. A method of controlling each component of the offset printing machine by the control unit 50 will be described later.

  Next, the printing operation by such an offset printing machine will be described using the graph shown in FIG. More specifically, an operation when the printing operation for the web W in one print item is terminated, the item for the web W is switched, and then the printing operation for the web W in another print item is started will be described. The operation shown below is performed by the control unit 50 controlling each component of the offset printing machine such as the roller driving unit 16 and the cutoff controller 30.

  When a printing operation is performed on the web W in one print item, the web W is printed at a constant normal printing speed (see state A in the graph of FIG. 2). The normal printing speed of the web W at this time is a speed at which the delivery roll 10 rotates at a rotational speed of 900 to 950 rpm, for example. At this time, the operation of the cutoff controller 30 is on, and the path length of the web W between the printing unit 12 and the cutting unit 14 is always adjusted to a desired size by the cutoff controller 30. It is like that.

  Then, when the production (printing) of about 90% of the production quantity is completed, when an operator inputs a command to start deceleration to the control unit 50 by using a touch panel of a control panel provided in the offset printing machine, the web W Starts to decelerate from the normal printing speed (see state B in the graph of FIG. 2). When the conveyance speed of the web W decreases and reaches a predetermined size within a range of 1/4 to 3/4 of the normal printing speed, the conveyance speed of the web W becomes constant at the predetermined size (FIG. 2). (Refer to the state C in the graph). At this time, the conveyance speed of the web W comes to coincide with the quality confirmation speed described later. Then, when the tension of the web W detected by the tension detection unit 40 becomes a constant magnitude in a state where the conveyance speed of the web W is constant, it is determined that the tension of the web W is stable, and the cutoff controller 30 operations are automatically switched off (see state D in the graph of FIG. 2). As a result, the adjustment of the path length of the web W by the cut-off controller 30 is stopped. Further, when the operation of the cut-off controller 30 is switched off, the conveyance speed of the web W starts to decrease again, and finally the web W is stopped (see state E in the graph of FIG. 2). In addition, the automatic operation by the control unit 50 is performed within the range indicated by the reference symbol M in FIG.

  Then, after the item of the web W is switched, when starting a printing operation for the web W in another print item, an operator inputs an operation start command to the control unit 50. Thereby, the conveyance speed of the web W starts to accelerate from 0 (see state F in the graph of FIG. 2). When the conveyance speed of the web W becomes the quality confirmation speed, the conveyance speed of the web W becomes constant at this quality confirmation speed (see state G in the graph of FIG. 2). For example, the roll 10 rotates at a rotational speed of 400 to 450 rpm. Then, when the tension of the web W detected by the tension detector 40 becomes a constant magnitude while the conveyance speed of the web W is constant, it is determined that the tension of the web W is stable, and the cutoff controller 30 operations are automatically switched on (see state H in the graph of FIG. 2). As a result, the adjustment of the path length of the web W by the cut-off controller 30 is resumed. Thereafter, the worker confirms the printing state such as the color tone and folding position of the web W, determines that there is no problem with the printing state of the web W, and inputs a production start command to the control unit 50 (graph in FIG. 2). 2), the conveyance speed of the web W starts to increase again, and finally the web W is conveyed at the normal printing speed (see the condition J in the graph of FIG. 2). Thereafter, the printing operation for other print items is performed. In addition, the automatic operation by the control unit 50 is performed within the range indicated by the reference symbol N in FIG.

  In the present embodiment, as shown in FIG. 2, when the operation of the cut-off controller 30 is turned off when the printing operation for the web W in one print item is finished, the web W conveyance speed and other printing are performed. The conveyance speed of the web W when the operation of the cut-off controller 30 is turned on when the printing operation for the web W in the item is started coincides. If the conveyance speeds of the two webs W are different, the amount of web W stretched before and after the switching of the print items will also differ, so that the cutting position of the web W by the cutting unit 14 is different. There is a problem of becoming. On the other hand, when the conveyance speeds of the two webs W match, the web W stretches before and after the print item is switched, so that the web W can be used even in the printing operation after the print item is switched. This cutting position is the same position as the printing operation before switching the print items.

  As described above, according to the offset printer and the printing operation of the present embodiment, when the printing operation for the web W in one print item is finished, the cut-off is performed with the web W conveyance speed being constant. By turning off the operation of the controller 30, the adjustment of the path length of the web W by the cut-off controller 30 is stopped, and then the printing operation for the web W in one print item is finished, and the web W in another print item is finished. When the printing operation is started, the cut-off controller 30 is caused to resume the adjustment of the path length of the web W by turning on the operation of the cut-off controller 30 in a state where the conveyance speed of the web W is constant. It has become. This eliminates the need to preset the compensator roller 32 when the web W is printed, thereby reducing the burden on the operator. Further, when the operation of the cut-off controller 30 is turned off when the printing operation for the web W in one print item is finished, and when the printing operation for the web W in another print item is started. Since the web W conveyance speed when the operation of the cut-off controller 30 is turned on coincides with each other, the elongation amount of the web W coincides before and after the switching of the print items. Even in the printing operation after the item switching, the cutting position of the web W is the same position as the printing operation before the printing item switching. For this reason, it is not necessary to adjust the cutting position of the web W at the time of printing the web W, and the amount of waste paper generated can be reduced.

  Further, in the offset printing machine and the printing operation of the present embodiment, as described above, when the printing operation for the web W in one printing item is finished and the printing operation for the web W in another printing item is started. The web W is conveyed so that the conveyance speed of the web W becomes a constant quality confirmation speed smaller than the normal printing speed when normal printing is performed on the web W. As shown in the graph of FIG. 2, the web W conveyance speed when the operation of the cut-off controller 30 is turned off when the printing operation for the web W in one print item is finished, and the other print items When the operation of the cut-off controller 30 is turned on when the printing operation for the web W is started, the conveyance speed of the web W is set to coincide with the quality confirmation speed.

  Note that the offset printing press and the printing operation according to the present invention are not limited to such a mode. The conveyance speed of the web W when the operation of the cut-off controller 30 is turned off when finishing the printing operation for the web W in one print item, and the cut when starting the printing operation for the web W in another print item As long as the transport speed of the web W when the operation of the off controller 30 is turned on, the transport speed of the web W at this time does not necessarily need to match the quality confirmation speed. As another aspect of the present invention, when the printing operation for the web W in one print item is finished, the operation of the cut-off controller 30 is turned off at the normal printing speed, and then the web W in the other print item is printed. When starting the printing operation, the operation of the cutoff controller 30 may be turned on at the normal printing speed.

  Further, in the offset printer and the printing operation of the present embodiment, as described above, when the printing operation for the web W in one printing item is finished, the web conveyance speed is constant, When the web tension detected by the tension detector 40 reaches a certain level, the operation of the cut-off controller 30 is turned off. In addition, when the printing operation for the web W in one print item is finished and the printing operation for the web W in another print item is started, the tension detection unit 40 in a state where the conveyance speed of the web W is constant. When the tension of the web W detected by the above becomes a certain magnitude, the operation of the cut-off controller 30 is turned on. Thus, after the tension of the web W is stabilized, the operation of the cut-off controller 30 can be switched on / off.

  The offset printing machine according to the present invention is not limited to such a mode. As another aspect of the present invention, the operation of the cut-off controller 30 may be switched on / off even when the web tension detected by the tension detector 40 does not have a constant magnitude. Further, in the offset printing machine according to still another aspect of the present invention, the installation of the tension detection unit 40 may be omitted.

  In the present embodiment, as described above, the cutoff controller 30 is provided between the printing unit 12 and the cutting unit 14 and moves the compensator roller 32 around which the web W is wound, and the compensator roller 32. A compensator roller driving unit 36 and a registration mark detection sensor 38 for detecting a registration mark attached to the web W being conveyed are provided. The cut-off controller 30 controls the compensator roller driving unit 36 based on the register mark detected by the register mark detection sensor 38 when the operation of the cut-off controller 30 is on, and the compensator roller 32. By adjusting the position, the path length of the web W between the printing unit 12 and the cutting unit 14 is adjusted. On the other hand, when the operation of the cutoff controller 30 is off, the position of the compensator roller 32 is adjusted. It is designed to be fixed. In the offset printing machine according to the present invention, the configuration of the cutoff controller is not limited to such a mode. As the cut-off controller, other than the configuration described above may be used as long as the path length of the web W between the printing unit 12 and the cutting unit 14 can be adjusted.

  Next, as a comparative example, FIG. 3 shows the web conveyance speed and the on / off transition of the cutoff controller in a conventional offset printing press.

  In the graph shown in FIG. 3, the printing operation for the web W in one print item is terminated by the conventional offset printing machine, and after the item of the web W is switched, the printing operation for the web W in another print item is started. The action is shown.

  When a printing operation is performed on the web W of one print item by a conventional offset printer, the web W is printed at a constant normal printing speed (see state A in the graph of FIG. 3). ). At this time, the operation of the cutoff controller 30 is on, and the path length of the web W between the printing unit 12 and the cutting unit 14 is always adjusted to a desired size by the cutoff controller 30. It has become.

  Then, when the production (printing) of about 90% of the production quantity is completed, when an operator inputs a command to start deceleration to the control unit 50 by using a touch panel of a control panel provided in the offset printing machine, the web W Is started to decelerate from the normal printing speed (see state B in the graph of FIG. 3). And the conveyance speed of the web W comes to reduce to 0 (refer the state C in the graph of FIG. 3). At this time, the operation of the cut-off controller 30 remains on. Further, even after the web W is stopped, the operation of the cutoff controller 30 remains on.

  Then, after the item of the web W is switched, when starting a printing operation for the web W in another print item, an operator inputs an operation start command to the control unit 50. As a result, the conveyance speed of the web W starts to accelerate from 0 (see state D in the graph of FIG. 3). When the conveyance speed of the web W becomes the quality confirmation speed, the conveyance speed of the web W becomes constant at the quality confirmation speed (see state E in the graph of FIG. 3). At this time, the operation of the cut-off controller 30 remains on. However, at this time, the worker needs to adjust the position of the compensator roller 32 in the cutoff controller 30. This is because the operation of the cut-off controller 30 is kept on so that the position of the compensator roller 32 follows as the web W is decelerated when the printing operation on the web W in one print item is stopped. Because it will end up.

  Thereafter, the operator confirms the printing state of the web W, such as the color tone and folding position, determines that there is no problem with the printing state of the web W, and inputs a production start command to the control unit 50 (graph in FIG. 3). ), The conveyance speed of the web W is increased, and finally the web W is conveyed at the normal printing speed (see the state G in the graph of FIG. 3). Thereafter, the printing operation for other print items is performed.

  As described above, in the offset printing machine in the comparative example as shown in the graph of FIG. 3, it is necessary to adjust the position of the compensator roller 32 in the cutoff controller 30 at the time of printing. is there. Further, in the offset printing machine according to the comparative example, when the printing operation for the web W in one print item is stopped, the cut-off is performed when the conveyance speed of the web W is reduced to a predetermined size during the deceleration of the web W. Although a method of automatically turning off the operation of the controller 30 is conceivable, the position of the compensator roller 32 is stable when the operation of the cut-off controller 30 is switched on / off when the conveyance speed of the web W is not constant. It is considered undesirable because it does not. As described above, the conventional offset printing machine has various problems as compared with the offset printing machine of the present invention.

DESCRIPTION OF SYMBOLS 10 Sending roll 12 Printing part 12a, 12b A pair of roller 14 Cutting part 14a, 14b A pair of roller 14c Blade 16 Roller drive part 30 Cut-off controller 32 Compensator roller 34 Guide guide 36 Compensator roller drive part 38 Registration mark detection sensor 40 Tension detection Part 42 tension detection roller 44 load cell 50 control part

Claims (4)

An offset printing machine that performs printing on a continuously elongated web.
A sending section for sending a wound web;
A transport unit for transporting the web sent from the sending unit;
A printing unit that performs printing on the web conveyed by the conveyance unit;
A cutting unit that cuts the web conveyed by the conveying unit and printed by the printing unit;
A cut-off controller for adjusting a web path length between the printing unit and the cutting unit;
A control unit for controlling the transport unit and the cutoff controller;
With
When the control unit finishes the printing operation for one web, the control unit turns off the operation of the cut-off controller in a state where the web transport speed by the transport unit is constant. When the adjustment of the web path length is stopped, and then the printing operation for one web is finished and the printing operation for another web is started, the web conveyance speed by the conveyance unit is constant. Controlling the conveyance unit and the cutoff controller to resume adjustment of the web path length by the cutoff controller by turning on the operation of the cutoff controller;
The conveyance speed of the web by the conveyance unit when the operation of the cut-off controller is turned off when the printing operation for one web is finished, and the operation of the cut-off controller when the printing operation for another web is started The web transport speed by the transport section when the is turned on is the same,
When the printing operation for one web that is performed at a normal printing speed when performing normal printing on the web is finished and the printing operation for another web is started, the control unit The transport speed is a constant quality confirmation speed smaller than the normal printing speed, and then the transport unit is controlled to be the normal printing speed,
The web conveyance speed by the conveyance unit when the operation of the cut-off controller is turned off when the printing operation for one web is finished, and the operation of the cut-off controller when the printing operation for another web is started An offset printing machine , wherein each of the web conveyance speeds by the conveyance unit when the is turned on is the quality confirmation speed . A tension detection unit for detecting the tension of the web conveyed by the conveyance unit;
When the control unit finishes the printing operation for one web, the web detection speed of the web detected by the tension detection unit is constant while the web conveyance speed by the conveyance unit is constant at the quality confirmation speed. When the tension becomes a certain magnitude, the adjustment of the web path length by the cutoff controller is stopped by turning off the operation of the cutoff controller, and then the printing operation for one web is finished. When starting a printing operation on another web, the web tension detected by the tension detection unit is constant while the web conveyance speed by the conveyance unit is constant at the quality confirmation speed. When this happens, turn on the cut-off controller to adjust the web path length by the cut-off controller. Offset printing machine according to claim 1, wherein the controller controls the transport section and the cut-off controller so as to restart. The cut-off controller is provided between the printing unit and the cutting unit, and a compensator roller around which a web conveyed by the conveying unit is wound, a compensator roller driving unit that moves the compensator roller, and the conveying unit A registration mark detection sensor for detecting a registration mark attached to the web conveyed by
The cut-off controller controls the compensator roller driving unit based on the register mark detected by the register mark detection sensor to control the position of the compensator roller when the operation of the cut-off controller is on. By adjusting the web path length between the printing section and the cutting section, the position of the compensator roller is fixed when the operation of the cutoff controller is off. offset printing machine according to claim 1 or 2, characterized in that is. An offset printing machine that performs printing on an elongated web that is continuously conveyed, a sending unit that sends a wound web, a conveying unit that conveys the web sent from the sending unit, and A printing unit that performs printing on the web conveyed by the conveying unit, a cutting unit that cuts the web that is conveyed by the conveying unit and printed by the printing unit, and between the printing unit and the cutting unit A printing method for printing on the web by an offset printing machine having a cut-off controller for adjusting the path length of the web in
When the printing operation for one web is completed, the operation of the cutoff controller is turned off in a state where the web conveyance speed by the conveyance unit is constant, and the printing unit by the cutoff controller and the Stopping the adjustment of the web path length with the cutting section;
When the printing operation for one web is finished and the printing operation for another web is started, the operation of the cut-off controller is turned on while the web conveyance speed by the conveyance unit is constant. Resuming adjustment of a web path length between the printing unit and the cutting unit by the cut-off controller;
With
The conveyance speed of the web by the conveyance unit when the operation of the cut-off controller is turned off when the printing operation for one web is finished, and the operation of the cut-off controller when the printing operation for another web is started The web transport speed by the transport section when the is turned on is the same,
When the printing operation for one web performed at the normal printing speed when performing normal printing on the web is finished and the printing operation for the other web is started, the web conveyance speed by the conveyance unit is: It becomes a constant quality confirmation speed smaller than the normal printing speed, and then the web is conveyed so as to become the normal printing speed.
The web conveyance speed by the conveyance unit when the operation of the cut-off controller is turned off when the printing operation for one web is finished, and the operation of the cut-off controller when the printing operation for another web is started The printing method according to claim 1 , wherein the web conveyance speed by the conveyance unit when turning on is the quality confirmation speed .

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