JP6472680B2 - Web conveying device in printing system - Google Patents

Description

  The present invention relates to a web conveyance device in a printing system such as a screen printing machine.

  Conventionally, a configuration shown in FIG. 4 is known in a web transport apparatus in which a web is transported through a printing unit of a screen printing machine and printing is performed on the web during the transport.

  In the configuration shown in FIG. 4, a slack portion of the web is provided downstream of the printing portion so that the web turning angle with respect to the printing cylinder 71 of the printing portion is widened. In this way, a stable printing operation is obtained. However, in such a configuration, the tension of the web is likely to change, and stable web transport is difficult. In particular, in the case of a transport path from a printing unit that is intermittently transported to a dryer that is continuously transported, it is difficult to smoothly perform a transition from intermittent transport to continuous transport while the web tension is stabilized. .

  Patent Document 1 discloses a configuration in which air is sucked between adjacent conveying rollers in a dryer chamber to bring the web toward the conveying roller.

JP 2003-54797 A

  The configuration of Patent Document 1 sucks a continuously conveyed web in a narrow gap between rollers, but does not disclose means for maintaining a web that transitions from intermittent conveyance to continuous conveyance in a stable state. Therefore, in Patent Document 1, it is difficult to stably convey the web in a configuration in which the web is shifted from intermittent conveyance to continuous conveyance and the tension is likely to fluctuate greatly.

  The present invention has been made paying attention to such problems existing in the prior art. The object is to provide a web transport device in a printing system capable of stably transporting a web that is shifted from intermittent transport to continuous transport.

  In order to achieve the above object, a printing unit that periodically prints the web while intermittently conveying the web, and a dryer that dries the printing ink on the web while continuously conveying the web after printing. In the web conveying device disposed between the two, the drawing unit provided on the downstream side of the printing unit, which is intermittently rotated in synchronization with the printing cycle and pulls out the web, and the web between the printing unit and the drawing unit An upstream side adjusting unit that detects the state of the pulling unit and adjusts the amount of rotation per unit time of the pulling unit according to the state, and a feed unit that is provided downstream of the pulling unit and feeds the web into the dryer And downstream adjusting means for detecting the state of the web between the feeding means and the pulling means and adjusting the rotational speed of the feeding means according to the state It is characterized in that the provided.

Here, the web includes a synthetic resin film, paper, and metal sheet.
In the above configuration, the printed web is pulled out by the pulling means, and sent to the dryer by the feeding means. In this case, the state of the web is detected by the upstream adjustment means, and the rotational speed of the pulling means is adjusted according to the state, so that the intermittent conveyance speed of the web is appropriately adjusted. Next, the web is switched to continuous conveyance by the feeding means and fed toward the dryer. At this time, the web state is detected by the downstream adjustment means, and the continuous conveyance speed of the web is appropriately adjusted.

  In this invention, there exists an effect which can perform intermittent conveyance and continuous conveyance stably in web conveyance.

1 is a simplified diagram illustrating a web conveyance device according to an embodiment. The perspective view of a 3rd guide roller and a 6th guide roller. The block diagram which shows the electric constitution of a web conveyance apparatus. The simplified diagram which shows a prior art example.

Hereinafter, an embodiment of a printing system will be described with reference to FIGS.
As shown in FIG. 1, the printing system of this embodiment includes a printing unit 10 that includes a printing cylinder 12 for screen printing and a screen frame 16. And the conveyance path | route 30 of the web 100 is provided so that this printing part 10 may be passed.

  That is, the web roll 11 on which the web 100 is wound, the printing cylinder 12, the first guide roller 13, the first suction box 14, and the second guide roller 15 are sequentially provided on the conveyance path 30 of the web 100 from the upstream side. Is arranged. The screen frame 16 is provided at a position facing the printing cylinder 12 with the web 100 interposed therebetween. On the downstream side of the second guide roller 15, a third guide roller 17, an inspection illumination table 18, a first suction roller 19, a fourth guide roller 20, a second suction box 21, a fifth guide roller 22, a sixth guide roller 27, a second suction roller 23 is arranged. The sixth guide roller 27 and the second suction roller 23 are disposed at an upstream position inside the dryer 24. The sixth guide roller 27 and the second suction roller 23 are linked by a linkage mechanism such as a belt, and are rotated at the same peripheral speed.

  In the dryer 24, a plurality of rollers 26 are arranged inside a housing 25, and the conveyance path of the web 100 is configured by these rollers 26. The inside of the dryer 24 is maintained at a high temperature by a heat source (not shown), and the printing ink on the web 100 conveyed through the conveyance path is dried.

  The printing cylinder 12 and the first suction roller 19 are intermittently rotated by servo motors 31 and 32 shown in FIG. 3 in accordance with the length of one printing range. The first suction roller 19 has a function of sucking the web 100 with air, and applies a conveying force to the web 100 in the sucked state. The servo motor 32 of the first suction roller 19, that is, the first suction roller 19, can change the amount of rotation per unit time. In the present embodiment, the rotation amount per unit time is changed by changing the rotation speed.

  The second suction roller 23 has a function of sucking the web 100, and applies a conveying force to the web 100 in the sucked state. The second suction roller 23 is continuously rotated by a servo motor 33. The rotation speed of the servo motor 33, that is, the second suction roller 23 can be changed, and the second suction roller 23 has a speed within a predetermined adjustment rate range with respect to a predetermined specified transport speed. Adjustable. This adjustment rate is appropriately changed according to the material of the web 100, the type of printing ink, and the like.

  The suction holes of the web 100 of the first and second suction rollers 19 and 23 are formed with a small diameter, and are set to appropriate values so that the suction pressure from the suction holes does not become excessive. For this reason, a suction mark is not formed on the web 100, and an effective conveyance force is applied to the web 100 without any unreasonableness, so that the upstream side and the downstream side of each of the first and second suction rollers 19 and 23. There is no significant difference in the tension of the web 100 between the sides.

  The first to fifth guide rollers 13, 15, 17, 20, 22 and the roller 26 in the dryer 24 are freely rotated. The web 100 in the dryer 24 is continuously pulled out while applying a weak tension by a drawing device (not shown) on the downstream side of the dryer 24.

  In the present embodiment, the first and second suction rollers 19, 23, the first to sixth guide rollers 13, 15, 17, 20, 22, 27, and the roller 26 in the dryer 24 are each formed by one cylindrical body. It is configured.

  As shown in FIG. 2, the third guide roller 17 on the downstream side of the first suction box 14 is subjected to low friction processing with a fluororesin or the like on the outer peripheral surface thereof. A pair of annular guide walls 171 are provided at both ends of the outer periphery of the third guide roller 17, and both width ends of the web 100 are guided by the guide walls 171 to guide the conveyance of the web 100. . Further, as shown in FIG. 2, a pair of annular guide walls 271 is provided at both ends of the outer periphery of the sixth guide roller 27 on the downstream side of the second suction box 21, and the webs are formed by both guide walls 271. Both width ends of 100 are guided, and the conveyance of the web 100 is guided. Both the guide walls 171 and 271 can be adjusted in position in the axial direction of the third guide roller 17, and are usually disposed at a position slightly outside the conveyance path of the web 100.

  The first and second suction boxes 14 and 21 include bottomed rectangular tubular housings 41 and 42 whose upper surfaces are open, and a plurality of fan motors 43 (only one is shown) attached to the lower portions of the housings 41 and 42. , 44 generates a downward suction flow in the housings 41, 42. The fan motors 43 and 44 are adjusted so as to have an appropriate air volume according to the transport conditions and printing conditions such as the thickness and rigidity of the web 100 and the size of the printing range. The fan motors 43 and 44 are attached to appropriate positions such as the lower side wall and the bottom wall of the housings 41 and 42. The fan motors 43 and 44 are selected such that the power and the number of the fan motors 43 and 44 can obtain an appropriate air volume in accordance with the transport conditions and printing conditions. The second suction box 21 is formed higher than the first suction box 14, that is, has a large vertical dimension and a large volume. Gap sensors 45 and 46 for detecting the distance from the web 100 are provided at the bottoms of the housings 41 and 42, respectively. The inner surfaces of the housings 41 and 42 of the first and second suction boxes 14 and 21 are smoothed so as not to scratch the web 100.

  At least one of the first and second guide rollers 13 and 15 and the at least one of the fourth and fifth guide rollers 20 and 22 positioned at the upper surface openings of the first and second suction boxes 14 and 21 are The position can be adjusted in the direction of arrow P in FIG. 1 in accordance with the rigidity and the strength of the air suction flow. Further, the guide rollers 13, 15, 20, 22 are moved integrally with the guide rollers 13, 15, 20, 22 between the guide rollers 13, 15, 20, 22 to be adjusted and the side walls of the first and second suction boxes 14, 21. The closing plates 131, 151, 201, and 221 are provided. And these obstruction | occlusion board 131,151,201,221 can suppress that a useless suction | inhalation flow arises between the guide rollers 13,15,20,22 and the side walls 411,421 of the suction box 14,21.

  The printing system according to the present embodiment includes a control device 61 shown in FIG. 3, and signals from the gap sensors 45 and 46 are input to the control device 61. The control device 61 stores an operation program for the web conveyance device, and controls the operation of each unit such as the servo motors 31 to 33 based on the operation program.

  In the present embodiment, the control device 61 constitutes a control means. The first suction roller 19 constitutes a drawing means, and the second suction roller 23 constitutes a feeding means. The gap sensor 45 and control device 61 of the first suction box 14 constitute upstream adjustment means, and the gap sensor 46 and control device 61 of the second suction box 21 constitute downstream adjustment means. The first and second suction boxes 14 and 21 and the fan motors 43 and 44 constitute a pool part, and the gap sensors 45 and 46 constitute a detection means.

Next, the operation of the web conveyance device in the printing system configured as described above will be described.
As the screen frame 16 reciprocates, the printing cylinder 12 and the first suction roller 19 are intermittently rotated synchronously, and the web 100 on the web roll 11 is intermittently unwound and drawn onto the conveyance path 30. . For this reason, screen printing is continuously performed on the web 100 on the printing cylinder 12. The web 100 that has passed through the printing cylinder 12 reaches the first suction box 14 via the first guide roller 13, and is pulled down so that the loop-shaped portion 101 is formed in the housing 41 by the suction flow by the fan motor 43. Pooled. Then, the position of the bottom of the loop-shaped portion 101 of the web 100 is detected by the gap sensor 45 in the first suction box 14, and the first suction roller 19 is set so that the position of the bottom of the loop-shaped portion 101 falls within a certain range. The rotation speed is adjusted.

  Therefore, even if a difference occurs in the conveyance speed of the web 100 due to slip or the like between the position of the printing cylinder 12 and the position of the first suction roller 19, the speed difference is absorbed. For this reason, the tension of the web 100 is kept substantially constant.

  The web 100 in the first suction box 14 passes through the second and third guide rollers 15 and 17 to the inspection illumination table 18, and the quality of the printing state is determined on the inspection illumination table 18.

  The web 100 passes through the first suction roller 19 and the fourth guide roller 20, and reaches the second suction box 21 by the drawing action of the second suction roller 23. Then, the web 100 is pulled down and pooled in the housing 42 so that the loop portion 102 is formed by the suction flow by the fan motor 44. Here, the second suction roller 23 is continuously rotated. For this reason, the web 100 is shifted from intermittent conveyance to continuous conveyance with expansion and contraction of the pooled loop-shaped portion 102, and is brought into the dryer 24 by the sixth guide roller 27 and the second suction roller 23 in the dryer 24. Be drawn.

  Then, the position of the bottom of the loop-shaped portion 102 of the web 100 is detected by the gap sensor 46 in the second suction box 21 and is continuously rotated so that the position of the bottom of the loop-shaped portion 102 is within a certain range. The rotational speed of the second suction roller 23 is adjusted.

  Therefore, even if there is a difference in the conveyance speed between the position of the first suction roller 19 and the position of the second suction roller 23 on the web 100 due to slip or the like, for example, every intermittent feeding cycle, that is, the conveyance amount per unit time. Even if a difference occurs, the difference is absorbed. In this case, the speed of the second suction roller 23 is adjusted within a range of a predetermined ratio with respect to a specified transport speed in the dryer 24. Therefore, the fluctuation of the passage time of the web 100 drawn into the dryer 24 in the dryer 24 can be suppressed, and adverse effects on the drying quality can be suppressed. For this reason, an even dry state can be obtained.

The web 100 from which the printing ink has been dried in the dryer 24 is sent from the dryer 24 to the next process.
The present embodiment has the following effects.

  (1) The printed web 100 is intermittently drawn by the first suction roller 19 and continuously drawn by the second suction roller 23 toward the dryer 24. In this case, the position of the loop-shaped portion 101 of the web 100 is detected by the upstream gap sensor 45 in the first suction box 14, and the rotational speed of the first suction roller 19 is adjusted according to the position. The intermittent conveyance speed is adjusted appropriately. Further, the web 100 is switched to continuous conveyance by the second suction roller 23 as described above, and is drawn into the dryer 24. At this time, the loop-shaped portion 102 of the web 100 is detected by the downstream gap sensor 46, and the continuous conveyance speed by the second suction roller 23 is appropriately adjusted. Therefore, the web 100 is stably conveyed, and the tension of the web 100 is maintained evenly.

  (2) In the two suction boxes 14 and 21, a part of the web 100 is pooled by the air flow to absorb the slackness of the web 100, and thereby moderate tension is applied to the web 100. In addition, the web 100 can be stably conveyed.

  (3) As described above, the rotation speed of the first suction roller 19 is adjusted based on the detection by the gap sensor 45 in the first suction box 14, and the intermittent conveyance speed and tension of the web 100 are adjusted appropriately. . Accordingly, the height of the web 100 in the first suction box 14 greatly fluctuates, the web 100 undergoes large vibrations and tension fluctuations, twists, the web 100 has an inner surface of the side wall of the first suction box 14, Contact with the inner surface of the bottom wall is prevented. For this reason, it is possible to prevent inconveniences such as creases and folds in the web 100, or dirt and scratches on the web 100 due to the contact, and ink transfer to unnecessary positions due to two folds.

  (4) Similar to the first suction box 14, the rotation speed of the second suction roller 23 is adjusted based on detection by the gap sensor 46 in the second suction box 21, and the continuous conveyance speed and tension of the web 100 are appropriate. Adjusted to. Therefore, the height of the web 100 in the second suction box 21 greatly fluctuates, the web 100 undergoes large vibrations and tension fluctuations, twists, the web 100 has an inner surface of the side wall of the second suction box 21, Contact with the inner surface of the bottom wall is prevented. For this reason, it is possible to prevent inconveniences such as ink transfer to an unnecessary position due to wrinkles or creases in the web 100, dirt or scratches due to the contact, or two folds.

  (5) Between the 1st suction box 14 and the 2nd suction box 21, the 1st suction roller 19 which provides conveyance force to the web 100 with moderate suction | attraction force is arrange | positioned. Therefore, the tension balance of the web 100 on the upstream side and the downstream side of the first suction roller 19 can be appropriately maintained.

  (6) The outer peripheral surface of the third guide roller 17 is subjected to low friction processing, and guide walls 171 are formed on both sides of the conveyance range of the third guide roller 17. In addition, guide walls 271 are formed on both sides of the conveyance range of the sixth guide roller 27. Therefore, when the conveyance direction or the conveyance position of the web 100 is displaced, the displacement is easily corrected by the guide wall 171 of the third guide roller 17 under a low resistance. Similarly, the displacement is corrected by the guide wall 271 of the sixth guide roller 27. In addition, the suction pressure of the first suction roller 19 on the downstream side of the third guide roller 17 and the suction pressure of the second suction roller 23 on the downstream side of the sixth guide roller 27 are set to appropriate low pressures, respectively. The displacement of the web 100 is further corrected without difficulty.

  (7) Since the first suction box 14 is provided immediately after the printing cylinder 12, the web 100 can be circulated over a wide range close to 180 degrees with respect to the outer circumferential surface of the printing cylinder 12. For this reason, slip on the printing cylinder 12 can be more reliably prevented, and accurate printing becomes possible.

  (8) Since the height of the second suction box 21 is made higher than the height of the first suction box 14 and formed into a large volume, the loop-shaped portion 102 of the web 100 can be formed larger, and the intermittent conveyance of the web 100 The transition to continuous conveyance can be performed smoothly. That is, since the printing cylinder 12 and the first suction roller 19 are intermittently rotated synchronously, the web 100 between the printing cylinder 12 and the first suction roller 19 is only intermittently conveyed. For this reason, the position and size of the loop-shaped portion 101 in the first suction box 14 do not vary much. On the other hand, since the web 100 shifts from intermittent conveyance to continuous conveyance between the first and second suction rollers 19 and 23, the position and size of the loop-shaped portion 102 of the web 100 in the second suction box 21 are small. It fluctuates greatly. In this case, since the second suction box 21 has a larger volume than the first suction box 14, the large variation is allowed, and the web 100 can smoothly shift to continuous conveyance.

  (9) The speed adjustment range of the second suction roller 23 is controlled based on the average feed amount per unit time of the printing cylinder 12. For this reason, the fluctuation | variation of the passage time in the dryer 24 of the web 100 can be suppressed, and drying conditions can be maintained constant. In this case, since the second suction box 21 is formed in a large volume, the speed adjustment can be performed slowly and smoothly over time, and the tension fluctuation of the web 100 can be suppressed.

  (10) As described above, in the transport device of the present embodiment, the first and second suction boxes 14 and 21 can absorb the tension fluctuation and vibration of the web 100, and the first suction between the boxes 14 and 21. The displacement and speed of the web 100 can be corrected or adjusted by the roller 19 and the third guide roller 17. Further, the speed and tension of the web 100 can be adjusted at the second suction roller 23 downstream of both boxes 14 and 21. Therefore, since the web 100 can be conveyed while adjusting the speed and tension of the web 100 over almost the entire range of the conveyance path 30 on the upstream side of the dryer 24, the web 100 can be stably tensioned and the speed fluctuation can be reduced. Can be transported.

The present invention is not limited to the embodiment described above, and may be embodied in the following manner.
-Omit inspection light table 18.

  In the above embodiment, the state of the web 100 is determined by detecting the positions of the loop-like portions 101 and 102 of the web 100 during conveyance. On the other hand, it is configured so as to determine the state of the web 100 by detecting the tension and speed of the web 100.

  In the embodiment, the rotation speed of the first suction roller 19 is adjusted to adjust the conveyance amount per unit time of the web 100. However, the rotation time in one cycle in the intermittent rotation of the first suction roller 19 Adjusting the conveyance amount by adjusting (the length of the rotation time between rotation stops).

A plurality of first suction boxes are provided between the printing unit 10 and the first suction roller 19 along the conveyance direction of the web 100.
A plurality of suction boxes are provided between the first suction roller 19 and the second suction roller 23 along the conveyance direction of the web 100.

  DESCRIPTION OF SYMBOLS 10 ... Printing part, 11 ... Web roll, 12 ... Printing cylinder, 14 ... 1st suction box, 16 ... Screen frame, 19 ... 1st suction roller, 21 ... 2nd suction box, 23 ... 2nd suction roller, 24 ... Dryer, 26 ... roller, 45 ... gap sensor, 46 ... gap sensor, 100 ... web.

Claims (7)

A web conveying device disposed between a printing unit that periodically prints a web while intermittently conveying the web and a dryer that dries the printing ink on the web while continuously conveying the web after printing. In
A pull-out means provided on the downstream side of the printing unit, which is intermittently rotated in synchronization with a printing cycle to pull out the web;
An upstream adjustment unit that detects a state of the web between the printing unit and the pulling unit and adjusts a rotation amount per unit time of the pulling unit according to the state;
A feeding means that is provided downstream of the pulling means, and continuously rotates at the same speed as the conveying speed in the dryer to feed the web into the dryer;
A web conveyance device in a printing system, comprising: a downstream side adjusting unit that detects a state of a web between the feeding unit and the drawing unit and adjusts a rotation speed of the feeding unit according to the state.   The upstream adjustment means includes a pool section that pools the web in a loop by air suction flow, a detection means that detects a state of the web in the pool section, and a unit time of the drawing means according to the detection result. The web conveyance device in the printing system according to claim 1, further comprising a control unit that controls a rotation amount of the printing system.   The web transport apparatus in a printing system according to claim 2, wherein the pool section is a suction box that generates an air suction flow therein, and the detection means is a gap sensor that detects a distance between the pool section and the web.   The downstream adjustment means includes a pool section that pools the web in a loop shape by air suction flow, a detection means that detects a state of the web in the pool section, and a rotation speed of the feeding means according to the detection result. The web conveyance apparatus in the printing system according to claim 3, further comprising a control unit that controls the apparatus.   5. The web conveyance device in a printing system according to claim 4, wherein the pool unit is a suction box that generates an air suction flow therein, and the detection unit is a gap sensor that detects a distance between the pool unit and the web.   6. The web conveying device in a printing system according to claim 5, wherein the suction box of the downstream adjustment means is formed to have a larger volume than the suction box of the upstream adjustment means.   The adjustment of the conveying speed of the feeding means by the downstream adjusting means is maintained within a predetermined adjustment rate range with respect to a specified conveying speed in the dryer. The web conveyance apparatus in the printing system as described in 2.